Information Systems Technician Training Series

Information Systems Technician Training Series
August 1997
Information Systems
Technician Training Series
Module 2—Computer Systems
Any reference within this module to “Radioman” or the former
“Radioman rating” should be changed to “Information Systems
Technician” and the “Information Systems Technician (IT) rating”.
The subject matter presented relates to the occupational
standards for the IT rating.
DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited.
Although the words “he,” “him,” and
“his” are used sparingly in this course to
enhance communication, they are not
intended to be gender driven or to affront or
discriminate against anyone.
DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited.
By enrolling in this self-study course, you have demonstrated a desire to improve yourself and the Navy.
Remember, however, this self-study course is only one part of the total Navy training program. Practical
experience, schools, selected reading, and your desire to succeed are also necessary to successfully round
out a fully meaningful training program.
COURSE OVERVIEW: In completing this nonresident training course, you will demonstrate a
knowledge of the subject matter by correctly answering questions on the following subjects: Computer
Hardware Startup, Computer Center Operations, and Data Management.
THE COURSE: This self-study course is organized into subject matter areas, each containing learning
objectives to help you determine what you should learn along with text and illustrations to help you
understand the information. The subject matter reflects day-to-day requirements and experiences of
personnel in the rating or skill area. It also reflects guidance provided by Enlisted Community Managers
(ECMs) and other senior personnel, technical references, instructions, etc., and either the occupational or
naval standards, which are listed in the Manual of Navy Enlisted Manpower Personnel Classifications
and Occupational Standards, NAVPERS 18068.
THE QUESTIONS: The questions that appear in this course are designed to help you understand the
material in the text.
VALUE: In completing this course, you will improve your military and professional knowledge.
Importantly, it can also help you study for the Navy-wide advancement in rate examination. If you are
studying and discover a reference in the text to another publication for further information, look it up.
1997 Edition Prepared by
DPC(SW) Walter Shugar, Jr. and
RMCS(SW/AW) Deborah Hearn.
Published by
NAVSUP Logistics Tracking Number
Sailor’s Creed
“I am a United States Sailor.
I will support and defend the
Constitution of the United States of
America and I will obey the orders
of those appointed over me.
I represent the fighting spirit of the
Navy and those who have gone
before me to defend freedom and
democracy around the world.
I proudly serve my country’s Navy
combat team with honor, courage
and commitment.
I am committed to excellence and
the fair treatment of all.”
1. Computer Hardware Startup . . . . . . . . . . . . . . . . . . . . .1-1
2. Computer Center Operations. . . . . . . . . . . . . . . . . . . . . 2-1
3. Data Management . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1
I. Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AI-1
II. Glossary of Acronyms and Abbreviations . . . . . . . . . . . . AII-1
III. References Used to Develop the TRAMAN . . . . . . . . . . . AIII-1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . INDEX-1
Trademark Credits
Microsoft is a registered trademark of Microsoft Corporation.
WordPerfect is a registered trademark of WordPerfect Corporation.
Administration and Security—This module covers Radioman duties relating to
administering AIS and communication systems. Procedures and guidance for
handling of classified information, messages, COMSEC material and equipment,
and AIS requirements are discussed.
Computer Systems—This module covers computer hardware startup, including
peripheral operations and system modification. Other topics discussed include
computer center operations, media library functions, system operations, and
troubleshooting techniques. Data file processes, memory requirements, and
database management are also covered.
Network Communications—This module covers network administration, LAN
hardware, and network troubleshooting. Related areas discussed are network
configuration and operations, components and connections, and communication
lines and nodes.
Communications Hardware—This module covers various types of
communications equipment, including satellites and antennas. Subjects discussed
include hardware setup procedures, COMSEC equipment requirements, distress
communications equipment, troubleshooting equipment, satellite theory, and
antenna selection and positioning.
Communications Center Operations—This module covers center operations,
including transmit message systems, voice communications, center administration,
quality control, and circuit setup/restorations. Guidelines for setting EMCON and
HERO conditions and cryptosecurity requirements are also discussed.
assignments. To submit your
answers via the Internet, go to:
The text pages that you are to study are listed at
the beginning of each assignment. Study these
pages carefully before attempting to answer the
questions. Pay close attention to tables and
illustrations and read the learning objectives.
The learning objectives state what you should be
able to do after studying the material. Answering
the questions correctly helps you accomplish the
Grading by Mail: When you submit answer
sheets by mail, send all of your assignments at
one time. Do NOT submit individual answer
sheets for grading. Mail all of your assignments
in an envelope, which you either provide
yourself or obtain from your nearest Educational
Services Officer (ESO). Submit answer sheets
Read each question carefully, then select the
BEST answer. You may refer freely to the text.
The answers must be the result of your own
work and decisions. You are prohibited from
referring to or copying the answers of others and
from giving answers to anyone else taking the
PENSACOLA FL 32559-5000
Answer Sheets: All courses include one
“scannable” answer sheet for each assignment.
These answer sheets are preprinted with your
SSN, name, assignment number, and course
number. Explanations for completing the answer
sheets are on the answer sheet.
To have your assignments graded, you must be
enrolled in the course with the Nonresident
Training Course Administration Branch at the
Naval Education and Training Professional
(NETPDTC). Following enrollment, there are
two ways of having your assignments graded:
(1) use the Internet to submit your assignments
as you complete them, or (2) send all the
assignments at one time by mail to NETPDTC.
Grading on the Internet:
Internet grading are:
Do not use answer sheet reproductions: Use
only the original answer sheets that we
provide—reproductions will not work with our
scanning equipment and cannot be processed.
Follow the instructions for marking your
answers on the answer sheet. Be sure that blocks
1, 2, and 3 are filled in correctly. This
information is necessary for your course to be
properly processed and for you to receive credit
for your work.
Advantages to
you may submit your answers as soon as
you complete an assignment, and
you get your results faster; usually by the
next working day (approximately 24 hours).
Courses must be completed within 12 months
from the date of enrollment. This includes time
required to resubmit failed assignments.
In addition to receiving grade results for each
assignment, you will receive course completion
confirmation once you have completed all the
For subject matter questions:
If your overall course score is 3.2 or higher, you
will pass the course and will not be required to
resubmit assignments. Once your assignments
have been graded you will receive course
completion confirmation.
[email protected]
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FAX: (850) 452-1370
(Do not fax answer sheets.)
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If you receive less than a 3.2 on any assignment
and your overall course score is below 3.2, you
will be given the opportunity to resubmit failed
assignments. You may resubmit failed
assignments only once. Internet students will
receive notification when they have failed an
assignment--they may then resubmit failed
assignments on the web site. Internet students
may view and print results for failed
assignments from the web site. Students who
submit by mail will receive a failing result letter
and a new answer sheet for resubmission of each
failed assignment.
For enrollment, shipping,
completion letter questions
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(Do not fax answer sheets.)
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After successfully completing this course, you
will receive a letter of completion.
If you are a member of the Naval Reserve,
you may earn retirement points for successfully
completing this course, if authorized under
current directives governing retirement of Naval
Reserve personnel. For Naval Reserve retirement, this course is evaluated at 5 points. (Refer
to Administrative Procedures for Naval
Reservists on Inactive Duty, BUPERSINST
1001.39, for more information about retirement
Errata are used to correct minor errors or delete
obsolete information in a course. Errata may
also be used to provide instructions to the
student. If a course has an errata, it will be
included as the first page(s) after the front cover.
Errata for all courses can be accessed and
viewed/downloaded at:
We value your suggestions, questions, and
criticisms on our courses. If you would like to
communicate with us regarding this course, we
encourage you, if possible, to use e-mail. If you
write or fax, please use a copy of the Student
Comment form that follows this page.
Student Comments
Course Title:
Information Systems Technician Training Series
Module 2—Computer Systems
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NETPDTC 1550/41 (Rev 4-00
Upon completing this chapter, you should be able to do the following:
Describe the different components of a computer system.
Describe how to startup a computer system.
Describe how to set parameters for operation and how to perform and
interpret diagnostic tests.
Explain what is involved in inspecting components, running system checks
and troubleshooting error conditions.
Explain how to perform computer interface changes, CMOS changes and
configuration changes.
Describe how to inspect, repair and install cables.
Explain how to install computer equipment and prepare computers for
We receive information in many different forms,
from our eyes, ears, nose, mouth, and even sensory
nerves. Our brains receive and accept this information,
work with it in some form or fashion, and then store it
away somewhere in the back of our minds (memories)
for future use. If what we are processing at the time
requires immediate attention, our minds direct us to
respond with words or actions. The computer’s brain
(the central processing unit) is designed to do basically
the same thing. That is, it receives information (input
data), works with this information (processes data), and
transmits this information (output data) to some form of
output media. This is often shown graphically as:
Computers do nothing more than what we instruct
them to do. They simply follow a set of internally stored
instructions (called a program or software) we provide
and process the data we feed into them.
The design of fifth-generation computers is such
that they will actually learn from previous experiences
and apply what they have learned. This is called
artificial intelligence. Artificial intelligence computers
manipulate data more efficiently, with parallel
processing, and understand written and spoken human
language. Ultimately, we may have a computer similar
to the human brain.
All electronic digital computer systems consist of a
central processing unit (CPU) and one or more
peripheral devices for inputting and outputting data and
processes the data and transfers the intermediate or final
results to an I/O device for storage or distribution.
programs. Figure 1-1 shows the CPU and the types of
peripheral (input and output [I/O]) devices you will find
in a computer system. The devices are interconnected
by electrical cables thru a bus to allow communications
between them. The CPU communicates with the
peripheral devices through input/output (I/O) channels.
The CPU executes stored programs and does all the
processing and manipulating of data. It contains the
circuits that control and perform the execution of
instructions using various types of memories. The I/O
devices simply aid the computer by providing and
receiving data and programs.
The brain of a computer system is the central
processing unit, which we refer to as the CPU. THE
CPU IS THE COMPUTER. It receives the data
transferred to it from one of the various I/O devices. It
In this section, you’ll learn about the control unit,
the arithmetic-logic unit, primary storage, secondary
storage, peripheral devices, I/O channels, and modems.
Figure 1-1.—Units/devices of a computer system.
The arithmetic-logic unit (ALU) performs all
arithmetic operations (addition, subtraction,
multiplication, and division) and logic operations.
Logic operations test various conditions encountered
during processing and allow for different actions to be
taken based on the results. The data required to perform
the arithmetic and logical functions are inputs from the
designated CPU registers and operands.
The control unit maintains order within the
computer system and directs the flow of traffic
(operations) and data. The flow of control is indicated
by the dotted arrows on figure 1-1. The control unit
selects one program statement at a time from the
program storage area, interprets the statement, and
sends the appropriate electronic impulses to the
arithmetic-logic unit and storage section to cause them
to carry out the instruction.
The ALU relies on basic items to perform its
operations. These include number systems, data routing
circuits (adders/subtracters), timing, instructions,
operands, and registers. Figure 1-2 shows a
representative block diagram of an ALU of a
The control unit does n o t perform the actual
processing operations on the data. Specifically, the
control unit manages the operations of the CPU, be it a
single-chip microprocessor or a fill-size mainframe.
Like a traffic director, it decides when to start and stop
(control and timing), what to do (program instructions),
where to keep information (memory), and with what
devices to communicate (I/O). It controls the flow of all
data entering and leaving the computer. It accomplishes
this by communicating or interfacing with the
arithmetic-logic unit, memory, and I/O areas. It
provides the computer with the ability to function under
program control. Depending on the design of the
computer, the CPU can also have the capability to
function under manual control through man/machine
The primary storage section (also called internal
storage, main storage, main memory, or just memory)
serves four purposes:
. To hold data transferred from an I/O device to the
input storage area, where it remains until the
computer is ready to process it. This is indicated
by the solid arrow on figure 1-1.
. To hold both the data being processed and the
intermediate results of the arithmetic-logic
operations. This is a working storage area
within the storage section. It is sometimes
referred to as a scratch pad memory.
The control unit consists of several basic logically
defined areas. These logically defined areas work
closely with each other. Timing in a computer regulates
the flow of signals that control the operation of the
computer. The instruction and control portion makes
up the decision-making and memory-type functions.
Addressing is the process of locating the operand
(specific information) for a given operation. An
interrupt is a break in the normal flow of operation of a
computer (e.g., CTRL + ALT + DEL). Control
memory is a random-access memory (RAM)
consisting of addressable storage registers. Cache
memory is a small, high-speed RAM buffer located
between the CPU and main memory; it can increase the
speed of the PC. Read-only memory (ROM) are chips
with a set of software instructions supplied by the
manufacturer built into them that enables the computer
to perform its I/O operations.
. To hold the processing results in an output
storage area for transfer to an I/O device.
The control unit is also capable of shutting down the
computer when the power supply detects abnormal
Figure 1-2.—Representative block diagram of an ALU.
(iron), which are strung on a grid of very thin wires.
Because computers store data in binary form (covered
in chapter 3), a two-state device is needed to represent
the two binary digits (bits), 0 for OFF and 1 for ON. In
core storage, each ferrite ring can represent a 0 bit or a 1
bit, depending on its magnetic state. If magnetized in
one direction, it represents a 1 bit, and if magnetized in
the opposite direction, it represents a 0 bit. These cores
are magnetized by sending an electric current through
the wires on which the core is strung. It is this direction
of current that determines the state of each core. Look at
figure 1-4. Since the cores store data in the form of
magnetic charges, core storage retains the data even
when the power is off. This is called nonvolatile
storage. An example of nonvolatile storage is ROM.
However, the process of reading from core is
destructive. This means the data must be electronically
regenerated after being read.
l To hold the program statements transferred from
an I/O device. This area is called the program
storage area.
Please note that the four areas (input, working,
output, and program storage) are NOT fixed in size or
location, but rather are determined by each individual
program’s requirements.
About now, you’re probably wondering how the
control unit is able to find these stored instructions and
data items. To understand this, picture memory as a
wall of post office boxes in a post office. Each box has a
different number (address) and represents a specific
storage location in memory, as shown in figure 1-3.
Like the mail in a post office box, the contents of a
storage location can change, but the number on the post
office box or memory address does not change. In this
manner, a particular program instruction or data item
that is held in primary storage can be located by
knowing its address. It is the responsibility of the
programmer to assign descriptive names to these data
items. This enables the computer program and the
computer to keep track of the storage location address of
each data item.
CHIP).— Semiconductor memory has hundreds of
thousands of tiny electronic circuits etched on a silicon
chip. Each electronic circuit, called a bit cell, can
represent a 0 bit or a 1 bit, depending on the current flow
in that bit cell. An OFF state represents a 0 bit, and an
ON state represents a 1 bit. Another name you’ll hear
used for semiconductor memory chips is integrated
circuits (ICs). (See figure 1-5.) Technological
developments have enabled even more circuits to be put
on a single chip, resulting in large-scale integration
(LSI) and very-large-scale integration (VLSI).
Primary storage can be classified by its physical or
functional characteristics.
Memory Types by Physical Characteristics
Primary storage devices may be classified
according to the type of magnetic or electronic principle
they use to store data. Some of the more common types
are magnetic core storage, semiconductor storage, and
bubble storage.
core storage, although not used as much as it used to be,
provides an easy way to show the general concepts of
memories, including integrated semiconductor and
bubble types of memories. Magnetic core storage is
made up of tiny doughnut-shaped rings made of ferrite
Figure 1-3.—Memory locations.
Figure 1-4.—Two-state principle of magnetic storage.
RAM. When you turn the power to the computer off, all
the stored data is lost. Also, when there is a power
failure and you do not have a backup power supply, all
the stored data is lost. As mentioned, this is not the case
with magnetic core storage. With core storage, the data
is retained even when there is a power failure or
breakdown, since data is stored in cores in the form of
magnetic charges, not electric current.
BUBBLE STORAGE.— Bubble memory is one of
the newer storage technologies, generally used in
laptops. It consists of a very thin crystal made of
semiconductor material. The molecules of the crystal
act as tiny magnets. Data is stored by changing the
polarity of these molecules, called magnetic domains.
The magnetic domains can be switched in an opposite
direction by passing a current through a control circuit
imprinted on top of the crystal. Like magnetic core
storage, bubble memory is nonvolatile. The data is
retained even when the power is turned off or there is a
power failure. Unlike magnetic storage, reading from
bubble memory is nondestructive. The data does not
have to be regenerated; it is still present after being read.
Figure 1-5.—Semiconductor memory chip exposed.
If we were to view these magnetic domains under a
microscope, they would look like tiny bubbles; hence,
the name, bubble memory. (See figure 1-6.)
Some of the advantages of semiconductor storage
are fast internal processing speeds, high reliability, low
power consumption, high density (many circuits), and
low cost. However, a drawback to this type of storage is
that it must have a constant power source. The term for
this is volatile storage. An example of volatile storage is
Memory Types by Function
Functionally, we can classify memory by its
operational features: random-access memory (RAM),
Figure 1-6.—Bubble memory.
read-only memory (ROM), programmable read-only
memory (PROM), and erasable programmable readonly memory (EPROM).
programmable read-only memory (EPROM) was
developed to overcome the drawback of PROM. Your
facility can buy blank EPROMs from the manufacturer,
and you can write programs developed at your
command/activity using a special device. The big
difference with EPROM is that you can erase it if and
when the need arises. The data and programs can be
retrieved many times. If you want to reprogram
memory, you first erase the EPROM with a burst of
ultraviolet light. This not only enables you to
reprogram when requirements change, but also, you can
erase and write the program again if a mistake is made
while programming the EPROM. In other words, a
mistake is not fatal, as it is when using PROM. You have
the flexibility to change programs to include
improvements or modifications in the future.
RAM, also called read/write memory, is like a
chalkboard. You can write notes, read them, and erase
them when you no longer need them. In the computer,
RAM is the working memory. Data can be read
(retrieved) from or written (stored) into RAM just by
giving the computer the address of the RAM location
where the data is stored or is to be stored. When the data
is no longer needed, you can simply write over it. This
allows you to use the storage again for something else.
Core, semiconductor, and bubble storage have randomaccess memory (RAM) capabilities.
computers, it is useful to have often used instructions,
such as those used to bootstrap (initial system load) the
computer or other specialized programs, permanently
stored inside the computer. The memory that enables us
to do this without the programs and data being lost even
when the computer is powered down is read-only
memory (ROM). Only the computer manufacturer can
install these programs into ROM, and, once installed,
they cannot be changed. Consequently, you cannot put
any of your own data or programs into ROM. Many
complex functions, such as routines to calculate square
root, translators for high-level programming languages,
and operating systems, can be stored into ROM.
Because the instructions are permanently stored, they
are quickly performed with accuracy. Also, your
computer facility can order programs designed for its
needs and have them permanently installed into ROM
by the manufacturer. To describe these permanently
installed programs, the term microprogram, o r
firmware, is used.
The last type of memory we briefly introduce here
is called secondary storage or auxiliary storage. This is
memory outside the main body of the computer where
we store programs and data for future use. When the
computer is ready to use these programs and data, it
reads them into primary storage. Secondary (auxiliary)
storage media extends the storage capabilities of the
computer. We need secondary storage for two reasons.
First, because the computer’s working memory
(primary storage) is finite and limited in size, it cannot
always hold all the data we need. Second, in secondary
storage, data and programs do not disappear when
power is turned off as they do when semiconductor
memories are used. Secondary storage media are
nonvolatile memories. This means the information is
lost only if you or the users intentionally erase it. The
three types of secondary storage we most commonly
use are magnetic tape, magnetic disk/diskette, and
magnetic drum.
(PROM).— Your computer facility can also buy
programmable read-only memory (PROM) already
programmed by the manufacturer or in a blank state.
Using a blank PROM and a device designed to write
(burn) a program into PROM, you can enter any
program into the memory. However, you cannot make
any changes to the program once it has been written into
PROM. But, PROM does provide flexibility not
available with ROM. Of course, you must be sure the
program is error free before it is written into PROM.
Peripheral devices include all the I/O devices used
with a computer system. When these devices are under
control of the CPU, we say they are online. When they
perform their functions independently, not under direct
control of the CPU, we say they are offline. T h e
peripheral devices described in the following
paragraphs are the ones we commonly use: magnetic
ink character readers, scanners, bar-code readers, keyto-online data entry terminals, magnetic tape units,
magnetic disk drive units, floppy disk drive units,
Key-to-Online Data Entry
cathode-ray tube (CRT) terminals, printers, and
Magnetic Ink Character Readers
Magnetic ink character readers read magnetically
inscribed information (like on a bank check) and
translate it to machine code.
Using a key-to-online data entry terminal, a person
enters input data into the computer directly from the
point of origin. This eliminates the need for human
intervention between source recording and the ultimate
processing by the computer.
Magnetic Tape Units
Scanners read text, drawings, and photographs and
convert them into electronic representations of the
Bar-Code Readers
Magnetic tape units move magnetic tape across
read/write heads that read and write the information.
Characters are recorded (written) on the tape in the form
of magnetized spots along the entire length of the tape.
On tape, data is stored in a sequential manner. In
sequential processing, the CPU must begin searching at
the beginning of the tape and check each record until the
desired data is found.
Bar-code readers scan data encoded in special bar
codes using reflective light and translate them to
machine code. Examples are the code on the front of this
manual and the codes on supermarket and department
store products.
Magnetic Disk Drive Units
Computer Consoles
Computer consoles usually include at least a
display and a keyboard. They may also include a
printer. The main console is located near the CPU and is
used by the computer operator to control the operations
of the computer system. Other consoles maybe used at
the peripheral devices to specify what media to mount,
what forms to use in the printer, what alignment is
required, and so on. They may also be used by the
peripheral equipment operator to start and stop jobs,
bring up other peripheral devices, requeue jobs, and so
on. Computer consoles are not normally used for
keying data from source documents for production jobs.
Magnetic disk drive units are storage devices that
read and write information on the magnetized surfaces
of rotating disks. The disks are made of thin metal,
coated on each side so that data can be recorded in the
form of magnetized spots. As the disks spin, characters
can be stored on them or retrieved from them in a
random (direct) manner. This direct accessing of data
has a big advantage over the sequential accessing of
data. You can direct the disk drive to begin reading at
any point.
Cathode-Ray Tube (CRT) Terminals
Floppy Disk Drive Units
A cathode-ray tube (CRT) terminal looks like a
television with a typewriter-like keyboard. It allows
you, the operator, to enter programs and data directly to
the computer. At the same time, it displays the program
or data on the display screen of the CRT. It can also
receive information directly from the computer and
display it on the screen. You can add a printer, a modem,
and adapters to the CRT terminal to provide for printed
output and communications through telephone lines.
Floppy disk drive units consist of a diskette drive
(the mechanism within which the diskette rotates) and a
controller containing the electronic circuitry that feeds
signals into and from the diskette. Diskettes are thin,
flexible platters (floppy disks) coated with magnetic
material so characters can be recorded on the surface in
the form of magnetized spots. Just like hard disks, as the
disk spins, characters can be stored on them or retrieved
from them in a random (direct) manner.
Printers are widely used output devices that express
coded characters as hard (paper document) copy. They
print computer results as numbers, letters, words,
symbols, graphics, or drawings. Printers range from
electric typewriters to high-speed printers. Low-speed
line printers include the dot-matrix printer commonly
used with personal computers. High-speed line printers
are normally used with larger computers to print supply
requisitions, paychecks, inventory, or financial reports
at 10 lines per second and faster. Laser printers provide
high quality print and print a full page at one time. They
are used with all types of computers.
simplex circuits are seldom used, because a return path
is generally needed to send acknowledgment, control
information, or some type of error signals.
DUPLEX CHANNELS.— A duplex channel
simply means that within each cable connection, there
are two paths (lines) for the transmission of data. One
path is for sending, and one is for receiving, similar to
your telephone. There are two types of duplex charnels,
half-duplex, and fill-duplex. A half-duplex channel is
capable of transmitting and receiving signals, but only
in one direction at a time, similar to citizens’ band (CB)
radio transmissions. Therefore, it is necessary to check
that the line is clear (idle) before starting a transmission.
A full-duplex channel provides for simultaneous
transmission in both directions, as in the use of the
Data Transmission Methods
Plotters are used with a computer to plot coordinate
points in the form of a graph. Digital incremental
plotters, in either online or offline operation with a
digital computer, provide a high-speed plotting system
of high versatility and reliability. For online operation, a
small adapter unit converts the computer output signals
to a form suitable for driving the plotter.
Data may be transmitted over a channel in one of
two ways, in either serial mode or parallel mode.
SERIAL MODE.— In serial transmission,
basically only three wires are needed: one to transmit
data, one to receive data, and one to ground. The data is
sent or received in the form of bits, one after another in
serial fashion, as shown in figure 1-7. This type of
transmission is highly desirable whenever the computer
system is linked to outside peripherals over a long
distance, such as remote terminals.
The input/output (I/O) channels provide for
communications between the CPU and all peripheral
devices. This is accomplished by electrical cables that
carry both data and control information to and from the
computer and peripheral devices.
PARALLEL MODE.— Parallel transmission is a
little more difficult to hookup than serial. It requires all
the data bits in a byte to be transmitted at one time (batch
mode); so you usually have nine or ten wires going
between the computer and the peripheral devices. You
have seven or eight lines for the data bits (figure 1-7)
that make up a letter, number, or special character; one
line to ground; and one or two lines called handshake
lines. The handshaking signals communicate
information back and forth between the peripheral
device and the computer. This information lets the
Signals are transmitted and received through a
cable connecting the CPU and its online devices. This
cable or line provides a path for the signal to travel and is
called a channel. Not only signals for monitoring but
also data are transmitted via channels. All channels
between the CPU and the peripheral devices are
designated as I/O channels. An I/O channel may be
used for data input, data output, or data input and output,
depending on whether the peripheral device handles
input only, output only, or both input and output.
Channel Types
I/O channels may be simplex or duplex.
S I M P L E X C H A N N E L S . — In simplex
operations, communications are in one direction only,
such as a radio. If a device such as a terminal were to be
connected to such a circuit, it would only be capable of
sending or receiving data, but not both. For this reason,
Figure 1-7.—Serial and parallel data transmission.
peripheral device know when the computer is ready to
accept another character and vice versa. This type of
transmission is used when you want to have fast data
transfer. Its drawback is that the computer cannot be too
far away from the peripheral device.
(the computer, peripherals, and accessories). You
should also be able to explain and demonstrate how to
use the different types of systems and applications
software to both computer and noncomputer personnel.
Last, but not least, you should know how to use the
various types of documentation supplied by the
manufacturer and software vendors.
We said that both signals and data can be
transmitted and received through cables (communications lines), which we refer to as I/O charnels. When
we transmit data directly to the computer over long
distances, it becomes necessary to add two other
devices, one at each end of the communications line.
These devices are called modems. The word modem is
an acronym for MOdulator-DEModulator. A modem
converts the digital signal produced by your terminal
(or the computer) to an audio signal suitable for
transmission over the communications line. The
modem at the other end of the line reconverts the audio
signal back to a digital signal before it is supplied to the
computer (or your terminal). If this conversion were not
carried out, the digital signal would degenerate and
become garbled during transmission.
As a communications specialist, you must be able
to set up, configure, upgrade, and initialize
microcomputer systems. You will need to know how to
install applications software so it works with the
system’s unique configuration. It will be your job to
help noncomputer users, end users, learn and
understand everything they need to know to work in a
microcomputer environment. This includes how to
interconnect various peripheral devices (keyboard,
monitor, printer) to the computer or system unit. It also
includes how to tailor the software for the operating
system and the applications software to each user’s
unique hardware configuration. You need to teach them
how to format and label diskettes; how to properly
manage, back up, clean up, and store their files. You
need to demonstrate routine operator maintenance and
explain security procedures. When users are having
problems with their micros, you may be called upon to
troubleshoot the systems using system diagnostics to
help isolate and determine whether the problem is
hardware or software related. You will also be expected
to make recommendations and/or arrangements to have
repairs made. There will be times when you will be
expected to make repairs if spare parts are available.
Microcomputers are everywhere. They stand
alone. They communicate with minis and mainframes.
They communicate with other micros through localarea networks. This communication is accomplished
by the use of software designed to make your computer
system function. The operating system software
enables you to install, select, and execute a variety of
programs. It does this through system/job control
languages and/or commands.
On microcomputers, you will need to be familiar
with all types of productivity software—the program
packages (or packaged software). These include word
processing, spreadsheet, and database programs at a
minimum. You also need to learn how to use local-area
network software, communications programs, graphics
programs, computer-aided design (CAD) programs,
desktop publishing programs, and so on. You, as a
professional data processor, may also be involved with
the construction and modification of batch files. This
provides a convenient way to save numerous keystrokes
for the user and allow the computer to run unattended
for some periods of time. All of these software
functions can and have been implemented on both large
and small scale computers.
Microcomputer users are not often computer
specialists. They are end users in the functional areas
doing computer processing specific to their
requirements. They need to know about the software:
the operating system, the communication software, and
the applications programs. They need to know about
the hardware: the microcomputer, the hard disks and
the floppies, the monitor, the keyboard, and the printer.
You will need to help them configure (set up) the
system, install the operating system and/or applications
program, and troubleshoot problems.
You need to know more than just merely how to
operate them if you are to become a communications
specialist. To be effective, you must keep up with the
latest changes in microcomputer technology and
terminology. You must have a good working
knowledge of microcomputer hardware components
On large computer systems, you maybe executing
programs through system/job control language
commands and processing jobs with multi-reel tape
files or files that reside on disk packs. You will be
responsible for ensuring that system control commands
are correct for a job, selecting a utility program to copy a
file or create a new file by specifying the parameters,
and working with an online database management
system that keeps up-to-date information on inventory
management or personnel.
In this section, we will examine the microcomputer
with its individual hardware components. We will
examine it from the inside. You will see how the
components work and how they interface and
interconnect with one another.
In looking over these last few paragraphs, possibly
you see yourself as a worker, a supervisor, a teacher, and
a troubleshooter, and rightly so. Microcomputers make
up a significant part of your profession; and because of
this, you will be the person that others will come to
looking for answers to their questions. The mere fact
that you are a communications specialist gives the
outside world, the end users, the impression you know it
all; that is, all there is to know about mainframes, minis,
and particularly microcomputers.
There will come a time when you maybe required
to replace or add a board in a computer to upgrade or
expand the capabilities of the system. A few examples
are as follows:
You may need to install an expanded memory
board to increase the amount of RAM to
accommodate larger applications.
You may have to replace the enhanced graphics
adapter (EGA) board with an video graphics
array (VGA) board to upgrade the graphics
capabilities of your system.
Microcomputers come in many shapes and sizes
with a variety of capabilities. A microcomputer can be
designed to operate in a stand-alone configuration or as
a component, an intelligent terminal, a server for a
complex local-area network (LAN) or large
distributed system. In this chapter, we will focus our
attention on desktop microcomputers that operate in a
stand-alone environment. Most stand-alone, desktop
microcomputer systems contain at least five hardware
components. They are as follows:
You may need to install a communications
You may receive a new software release that
requires the presence (or absence) of certain boards to
function properly. You do not want to find out too late
that your software is incompatible with your hardware.
You might have to answer questions such as the following: Will the graphics software the user wants to order
work with the graphics board currently installed in the
system? Does the user’s system have sufficient room to
accommodate another hard disk drive? A diagnostics
routine may indicate that the disk controller board needs
to be replaced, and so on, and so on. For reasons such as
these, you will need to know a lot more about microccomputers (both inside and out) if you are to be effective
and able to help others in your work environment.
. The computer or system unit, which normally
houses the microcomputer (microprocessor
chip[s]) along with other hardware components
and secondary storage devices;
. Secondary storage devices (floppy disk drives,
hard disk drives, and magnetic tape units),
housed either in the system unit or separately;
The Computer or System Unit
. A monitor (standard output device);
The computer or system unit is the main part or
heart of the total microcomputer system. Inside this unit
all data is processed, arithmetic and logic functions are
performed, and control is maintained for the system. If
you were to remove the outer cover from this unit
(figure 1-8), you would see a power supply and as many
. A keyboard (standard input device); and
. A printer (an additional output device—for hard
Figure 1-8.—A microcomputer system unit with the cover
as two floppy disk drives and two hard disk drives or
any combination thereof, depending upon the particular
configuration of your system. You would also see
several boards (also referred to as cards). Some boards
are used to control the peripheral devices of the system,
while other boards work in conjunction with the
microprocessor that is located on the system or
motherboard itself. These boards provide the flexibility
to add a variety of capabilities to a basic system. Certain
boards are required, such as the system board that
contains the main microprocessor(s). Others you might
add to control a light pen or mouse device, or to handle a
communications interface.
video display board (figure 1-9). We will take a look at
small computer systems interface (SCSI) adapter board
is used to control peripheral equipment, such as a CDROM drive.
SLOTS B, D, E, F, AND H.— Slots B, D, E, F, and
H on this particular micro are reserved for future use.
Most disk controller boards are capable of supporting
two internal hard disk drives, two internal floppy drives,
and one external magnetic tape drive for tape backup.
Looking inside the computer system unit (figure
1-8), you will notice there are 5 available slots for board
insertion. These various boards are plugged into what is
called the motherboard. The motherboard is a printed
circuit board that transmits the power and electronic
signals between the other boards and peripheral
devices. It is mounted to the bottom of the chassis of the
computer, as shown in figure 1-9. Memory chips, on the
newer micros, called single in-line memory modules
(SIMMs), are located on the motherboard in a group of
4 or 8 slots. In older micros the memory chips are
located on a memory expansion board. Most
microcomputers also have a lithium battery installed on
the motherboard. It provides power to the real-time
clock when the system is turned off. The life
expectancy of this battery is 3 to 5 years. Other boards
you are likely to see in a typical microcomputer are the
disk controller board, SCSI adapter board, and
video display board includes graphics memory chips to
provide the system with graphics capabilities. Most
micros come from the factory set for VGA (video
graphics array) settings.
By now, you should have a pretty good idea of what
you can expect to see inside the system unit in the way
of microcomputer boards. Before installing any
internal components within the system unit, you must
first carefully remove the outer cover. Be sure you are
authorized to make such changes before removing the
cover. However, before you go looking for a
screwdriver, read the owner’s manual very carefully,
paying particular attention to the section on cover
removal and the steps to follow. For example, the
owner’s manual might say: “Once all cabinet screws
have been removed, raise the cover, keeping it as high as
Figure 1-9.—Boards within the microcomputer system unit and their locations.
possible while pulling it forward for removal.” This
action ensures that none of the internal wires, cables, or
connectors are accidentally pulled loose and avoids
possible damage to the components already installed
inside the system unit.
So that you will have a better understanding and
appreciation for this microcomputer, we will take a
closer look at microprocessor chips and see how they
differ from one another. We will also examine what all
this means to you from a communications specialist’s
Microprocessor Chips
Figure 1-11.—A microprocessor being mounted onto the
carrier package.
All microcomputer systems are driven by one or
more microprocessor chips. A microprocessor chip is
made up of thousands of integrated circuits that contain
all of the essential elements of a central processing unit
(figure 1-10). These include the control logic,
instruction decoding, and arithmetic-processing
Of all the boards in the microcomputer, the system
board is the most important. But what are the functions
of the microprocessor chip? Are all microprocessor
chips designed to perform the same functions?
Basically, yes; but there are some significant
differences in how they perform their functions. You
should be aware of these differences, especially if you
will be working with several different types of micros.
To be useful, the microprocessor chip (which is no
bigger than your fingernail) must be mounted onto what
is called a carrier package (figure 1-11). This carrier
package along with other chips-memory chips (RAM
and ROM) and I/O integrated circuit chips—are
plugged into specific socket locations on a circuit
board called the system board or the motherboard
(figure 1-12).
A chip, is a chip, is a chip, OR IS IT? Computer
chips, like everything else in data processing, have
some rather unique and unusual names; names like
Zilog Z-80A, Intel 80C88, MOS Technology 6502,
Motorola 68000, and so on. Some chip names contain
letters and numbers. Others contain only numbers.
Having the right microprocessor chip in your computer
Figure 1-12.—The system/motherboard showing placement of
the microprocessor, RAM, ROM, and integrated circuit
Figure 1-10.—A typical microprocessor computer chip.
microprocessor chip. For example, IBM uses an Intel
8048 chip on the keyboard to determine which keys are
being depressed and also to check to see that the
keyboard is communicating properly with the
microprocessor. In fact, most peripheral devices have
one or more specialized processors embedded in them.
system makes all the difference in the world in terms of
internal processing speeds (33MHz, 66MHz,
120MHz, and so on), number of bits handled (8, 16, or
32 bits), memory size (640K, 4M, 16M, and up), and
the applications software it will run.
Each microcomputer contains a specific
microprocessor chip as its main processor. A
microprocessor chip can typically handle 8, 16, or 32
bits of information at once. Generally speaking, the
more bits a computer can manipulate at one time, the
faster it can process program instructions and data, and
the larger the main or primary memory it can
accommodate. The type of chip in your computer or
system unit also has a great effect on what you can do
with your micro. For example, operating systems are
written to serve a specific microprocessor chip, and
applications programs that work under one operating
system are not likely to work under another unless the
program is modified. Many applications programs
come in several versions to provide compatibility with
several operating systems.
Other specialized processors are the Intel 80287
and the faster 80387 math coprocessor. These are
special-purpose programmable microprocessors
designed to perform arithmetic calculations up to 100
times faster than the main microprocessor. A math
coprocessor executes arithmetic instructions that would
normally be handled by the main microprocessor’s
arithmetic-logic unit (ALU) as well as those the main
microprocessor cannot perform because of register
constraints. The 80287 and 80387 are companion chips
to the Intel family of microprocessors. Computer
systems using the 80 series of chips are capable of very
high-speed mathematical operations when the math
coprocessor chip is plugged either into or alongside the
system or motherboard. Math coprocessor chips are
used in SX version computers. The SX denotes that the
computer does not have a math coprocessor integrated
into the cpu chip. A DX version computer has a math
coprocessor integrated into the cpu chip. With the
development of the Pentium chip, math coprocessor
chips were no longer required to perform arithmetic
These are just a few of the reasons why we say it is
very important that you read all the documentation
that comes with your microcomputer. The Navy uses
many different types of microcomputers and
microprocessor chips. To give you an idea of the
variety, table 1-1 lists some of the microprocessor chips.
Specialized Processors
Specialized processor chips have been developed to
shift some of the workload from the main
To the system unit we must add input/output
devices to communicate between us and the computer.
These include the monitor, the keyboard, disk drives,
and the printer. We will look at each of these devices in
the following sections, along with some of the more
common accessories found on microcomputers, such as
surge protectors, parallel to serial converters and vice
versa, null modems, cables, and switches used for
sharing hardware.
Table 1-1.—Microcomputer Chips and Microcomputers
Monitors (Display Devices)
Monitors are used as output devices on
microcomputers. They are peripheral devices that
contain a display like a television viewing screen. They
are the principal link between you and the
microcomputer. Their sole purpose in life is to allow the
microcomputer to communicate its actions to you (the
user), so you can act upon those actions to accomplish
whatever job you are doing. They display output from
the computer. The monitor is one of the most important
peripherals to a micro and is certainly the most visible.
Located on the front of most monitors, generally
below the screen, you will find some type of power
on/off switch. It will probably have a green lightemitting diode (LED) indicator light. When this light is
lit, the monitor is on and power is supplied.
Quite often, the term monitor is used interchangeably
with such names as screen, display, display device,
and cathode-ray tube (crt).
At this point, it would be helpful for you to have a
basic understanding of display technology, along with
the various types of display/graphics cards used to
support display devices. Having a good working
knowledge in this area will put you in a better position to
assist the end users in answering any technical
questions they may have, as well as aid you in
troubleshooting and diagnostics testing.
Monitors can display information in either
monochrome or color, depending on their design.
Monochrome displays produce output images using a
single foreground color, such as black, and a single
background color, such as white. This provides you
with black text on a white background. Using a
technique known as reverse video (that is, reversing the
color of the pixels or dots on the screen), it is possible to
have white text on a black background. Monochrome
displays also come in amber (a yellowish brown) and
green. Amber and green are considered more pleasing
and less stressful to the eyes than black and white. Most
color displays are of the red-green-blue (RGB) type.
Depending upon the sophistication of the display device
and the amount of RAM available with the
microcomputer, you may be able to display from 8 to
16,000,000 colors.
A key characteristic of any display device is its
resolution, which determines the sharpness and clarity
of the screen image. If you look closely at your display,
you’ll notice that images are formed by lighting up tiny
dots on the screen. Resolution is measured by the
number of these dots or pixels (short for picture
elements) per square inch of screen. Whether you are
working with text or graphic images, the more pixels
used to form characters/images and the more pixels that
can be packed per square inch of screen, the higher the
resolution and the sharper the character/image. For
example, a display resolution of 1280 by 1024 means
that the screen consists of 1280 vertical columns by
1024 horizontal rows of dots, or if you prefer 1280 ×
1024 = 1,310,720 pixels.
The distance between the dots is called dot pitch.
Smaller pitch values indicate sharper images. The
original IBM PC color monitor had a dot pitch of
0.43mm. The state-of-the-art displays marketed today
have a dot pitch of 0.28mm or less.
Now, let’s take a closer look and discuss some of the
more common features you are likely to find on monitors. These include brightness, contrast, and sizing. We
will also discuss the various types of video display and
graphics boards/cards that are used to support them.
Most display devices are capable of providing you
with both text and graphics (pictures). Text output
consists of letters, numbers, and special characters only.
Text characters are created on the screen in the form of a
You use the brightness control to vary the
brightness of displayed data. When adjusting this
control, you turn the dial until the intensity is at the
brightness level desired. Use the contrast control to
vary the difference between the nonintensified colors
and the intensified colors.
Monitors with a sizing feature allow you to increase
or decrease the physical size (the height and width) of
the displayed information on your screen. Some models
use control knobs. Others use two-position switches.
Depending on the type monitor you have, these control
knobs or switches could be located just about anywhere;
on the back, on the sides, or tucked away underneath the
monitor to keep them from being accidentally hit, as
shown in figure 1-13.
Figure 1-13.—Monitor controls, switches, and indicators.
dot-matrix similar to a dot-matrix printing device. Normally, it is the display device manufacturer who will
decide on a specific matrix size—say, 7 by 12 (for a total
of 84 dots or pixels) to display each character of text
(see figure 1-14). The more pixels used to form characters, the higher is the resolution. Most display devices
use 25 rows of 80-character lines when displaying text,
and there are some that will display 50 rows of 132character lines in what is called a compressed mode.
Of all the components that make up a
microcomputer, you will become most familiar with the
keyboard. It will probably be your primary means for
inputting programs and data on microcomputers.
Graphics output consists of complex picture
images, which brings us to the term bit mapping. Bit
mapped graphics use a technique whereby each dot or
pixel on the screen can be addressed and individually
controlled by the user. This allows you to create
virtually any type of image on the screen. Knowing this
should give you abetter understanding and appreciation
of why resolution is so important, especially if you are
viewing two documents on the screen at the same time,
side-by-side, or working with three-dimensional
Keyboards come in many shapes and sizes, have
different numbers and arrangements of keys, differ in
respect to touch, and have special keys to allow you to
communicate specific software commands. Most
manufacturers have designed their keyboards as
separate devices so you can place them wherever it is
convenient. Other manufacturers have designed their
keyboards into the display/monitor device or system
The type of monitor or display device you have on
your microcomputer will often dictate what type of
display/graphics board you can plug into your system
unit. The key word here is compatibility. S o m e
display devices can automatically switch between any
standard display/color graphics card. Having such a
display device or monitor allows you to upgrade the
video/ graphics board in the system unit without having
to upgrade the display unit. However, not all display
devices are designed to accept the different types of
video boards available primarily because of their
resolution characteristics. It is important that you read
all the documentation that comes with your micro to
determine whether or NOT your display device will be
compatible with the video/graphics board you want to
The important things you need to know about
keyboards are the types of keys and the function and
placement of each. All keyboards have the alphabetic
characters (upper and lower case), numbers, and some
special characters. In addition, keyboards have special
function keys and control keys that are defined by the
operating system or the program. We will briefly
describe an example keyboard and explain some of the
more common keys you are likely to use.
CHARACTER KEYS.— The arrangement of letter,
number, and special character keys may vary. The
QWERTY keyboard shown in figure 1-15 has the same
format as the conventional typewriter.
Figure 1-14.—The letter “L” as formed within a 7- by 12-dot
Figure 1-15.—QWERTY keyboard.
SHIFT KEY The SHIFT key works in
conjunction with other keys. When you hold
down the shift key (or depress the CAPS LOCK
key) and press a letter key, the letter will be
displayed and stored in UPPER CASE. When
you hold down the shift key with the number
keys on the row above the alphabetic keys, the
special characters shown on the top of each key
will be displayed and stored. The CAPS LOCK
key on this particular keyboard contains a light
within the key itself. When it is lit, you know the
caps lock feature is on.
Figure 1-16.—Control keys.
ALT KEY The ALTERNATE key also works in
conjunction with other keys to increase the
number of functions you can communicate to the
CONTROL KEYS.— In looking at figure 1-16,
you will notice several keys are outlined in bold. These
are some of the more common control keys you can
expect to use when working with just about any
keyboard. Beginning in the top left-hand corner, you
see the ESC(ape) key, TAB key, CTRL (control) key,
SHIFT key, ALT (alternate) key, and to the immediate
right are the SPACE BAR and the CAPS LOCK key.
On the right-hand side of the keyboard are the BACK
SPACE key and the ENTER/RETURN key. Depending
on what program/software you are using, the keys may
be assigned different functions.
SPACE BAR Press the SPACE BAR whenever
you want to enter a blank character, a space.
SPACE key moves the cursor one position to the
left, erasing the character that was previously
ENTER/RETURN KEY By pressing the
ENTER/RETURN key, you tell the computer
(microprocessor) you have entered data or
instructions and are ready for processing.
Depressing this key also returns the cursor to the
beginning of the next line.
ESCape KEY The ESCAPE key usually stops
the execution of a program or function e
TAB KEY The TAB key moves the cursor to the
next tab stop position.
figure 1-17, you will notice once again several keys
outlined in bold. These are special function keys you
can expect to use. Located on the far left side of the
keyboard, you see 12 special function keys labeled F1
through F12. On some keyboards you will find these
function keys have been placed across the top of the
keyboard, above the letters and numbers. The number
of these function keys may also vary. To the right of the
keyboard is another group of special function keys.
CTRL KEY The CONTROL key performs
special functions within the system/program. It
is used in combination with other keys to
increase the number of functions you can specify
to a system or program. For example, on most
IBM compatible systems, when used with the
ALT and DEL keys, it reboots the operating
Figure 1-17.—Special function keys.
These include a 10 key (0-9) numeric keypad and the
cursor control keys. Also, beginning on the top row at
the right, you see the NUM(eric) LOCK key, SCROLL
LOCK key, PAUSE key, and the PRT SC (print screen)
key. Located on the bottom right-hand side of the
keyboard are the INS(ert) and DEL(ete) keys. The
purpose/function of each of these keys is as follows:
for cursor control. This is particularly helpful
when you are doing a lot of data entry of
SCROLL LOCK KEY Applications software
uses the SCROLL LOCK mode of the key to
control screen scrolling.
PAUSE KEY The PAUSE key is used to
interrupt program execution.
FUNCTION KEYS F1-F12 These specialpurpose keys are used to communicate special
functions to the operating system, such as MSDOS, or to applications software. The meaning
of each is defined by the particular software.
This simplifies tasks that might otherwise
require several keystrokes. These keys can also
be used with other keys to increase the number of
functions you can specify to a program.
PRT SCreen KEY The PRT SCREEN key is
activated by depressing it in conjunction with the
SHIFT key depressed. This sends whatever is
displayed on the monitor’s screen to the printer.
INSert and DELete KEYS These keys allow
you to insert or delete a character at the position
of the cursor when neither the SHIFT nor the
NUM LOCK keys are depressed.
numeric keypad, press the NUM LOCK key.
The NUM LOCK key may contain an indicator
light within the key to indicate when it is ON.
Use the numeric keypad just like a calculator
keypad to enter numbers you will be using in
mathematical functions.
It is important to remember that any key or
combination of keys can be assigned special meaning
by a program. Therefore, the keys may have different
meanings and functions, depending on the program you
are using. Once again, we remind you, read all the
documentation that comes with each program and with
the computer system.
CONTROL keys are most important. They
allow you to move the cursor from one place to
another on the display screen. Remember, the
cursor is the indicator, the spot of light on the
screen, which lets the user know where the next
entry will be made. On the keyboard shown in
figure 1-17, the cursor control keys are located in
two locations, both on the numeric keypad and as
a separate keypad. When the NUM LOCK key is
OFF, you can use the arrows on keys 2,4,6, and
8 to control cursor movement one line up or
down, or one position to the left or right, as
shown by the direction of the arrow. The
remaining cursor control keys on keys 1, 3, 7,
and 9 are used to move the cursor to other parts of
the screen or document/data (for example, the
end of a line [END key] or the top of the next
page [PgDn key]). Some software packages use
the cursor control keys in combination with each
other or with other keys to increase the number of
ways and the speed with which you can move the
cursor. Read the software documentation; the
faster and more efficiently you are able to move
the cursor through a document or database, the
faster and more efficiently you will get the job
done. Some keyboards have separate arrow keys
Disks and Disk Drives
Magnetic disks, regardless of their type or size, are,
without a doubt, the most important secondary storage
medium used with microcomputers. Disks provide fast
retrieval of information. The disk’s physical
characteristics, flat and round, allow the disk drive
direct access to data. Put simply, the processing unit
goes directly to a designated disk drive, seeks out the
specific location on the disk where the data is stored,
and immediately retrieves it. The disk drive does NOT
have to read through a series of records before reaching
the one desired, as is the case with magnetic tape units.
The two forms of magnetic disk typically used with
microcomputers are the floppy disk (diskette) and the
hard disk. Let’s look at the sizes and construction of
each and at the disk drive devices that read from and
write to them.
diskette is also referred to as a floppy disk, or just plain
floppy, because it is a round, flexible platter.
Physical Characteristics.— The platter is
enclosed in a plastic jacket. At present, diskettes come
in two sizes (diameters): 5 1/4 (5.25) inches and 3 1/2
(3.50) inches (see figure 1-18). The platter is made of a
tough plastic that is coated with a magnetic oxide
material, allowing it to be magnetized. The inside of the
plastic jacket is lined with a soft wiping material that
continuously cleans the floppy disk as it spins within the
jacket. Look at figure 1-19; you will notice a hole in the
middle of the diskette. It is referred to as the center
hub. The hub makes it possible for the floppy disk
drive’s spindle to rotate the diskette inside the jacket.
The recording window allows the read-write head
mechanism of the floppy disk drive to come into contact
with the diskette so it can read from or write data onto
the diskette’s surface. Located just to the right of the
center hub is what we refer to as an index hole. This
index hole (and corresponding hole [or holes] in the
diskette), marks the first sector or starting point on the
diskette. The sectors on a diskette are controlled by
timing. On a soft-sectored diskette, the timing is
controlled by the software; therefore, only one timing
hole is needed on the diskette. On a hard-sectored
diskette, the timing is controlled by the hardware, and
the diskette has several timing holes.
Figure 1-19.—A typical 5.25-inch diskette.
microcomputer system. Floppy disk drives that use
hard-sectored diskettes read and write data faster.
However, the diskettes are more expensive and can only
be presectored (reformatted) for a specific system,
such as an IBM compatible or a Macintosh.
Most diskettes sold today are soil-sectored because
the wide range of microcomputers and their operating
systems vary considerably in respect to sectoring requirements. For now, the important thing to remember
about sectoring is the fact that no matter what type of
diskette you are working with (soft- or hard- sectored),
it must be formatted before it is usable for storing data.
Types of Floppies/Diskettes.— The diskettes you
will be using must be compatible with the floppy disk
drives on your microcomputer system. Diskettes can be
soft-sectored or hard- sectored. Depending upon the
disk drive’s characteristics, the disk drive can record
data on one side of the diskette or both and can record
data in one of several bit densities, depending upon how
the diskette is formatted.
Storage Capacity.— Although diskettes are
relatively small in size, they can store a respectable
amount of data. Some diskettes are single-sided,
single-density, whereas others are double-sided,
single-density; double-sided, double-density; or
double-sided, quad-density.
When you are working with a soft-sectored
diskette, you must use your microcomputer and a utility
routine or program (in this case, a formatter program) to
sector or format each diskette for you. On most
microcomputer systems, using the F O R M A T
command will automatically sector the diskette for you.
When we refer to a diskette as being double-sided,
double-density, what are we really saying? We are
saying the floppy disk drive is able to read from and
write to both sides of the diskette (hence, the term
double-sided), and that each sector on the disk can store
512 bytes of information (instead of the 256 bytes that
can be stored on a single-density diskette); hence, the
term double-density. A diskette’s capacity is also
affected by the number of tracks per side. Therefore, if
you wanted to know the total storage capacity of a
double-sided, double-density diskette with 80 fifteensector tracks per side, then you would use the following
formula to calculate the number of bytes:
If you are working with hard-sectored diskettes,
then you need not format them. They have already been
presectored by the manufacturer for your specific
Figure 1-18.—Floppy disks/diskettes used on microcomputers.
To review, multiply bytes (5 12) times sectors (15) times
tracks (80) times sides (2). This gives the total capacity
of the diskette, 1.2M bytes.
Write Protect Feature.— Like all other media,
floppy disks/diskettes must also have a way of being
protected from a user accidentally writing on them.
This is accomplished with a write-protect notch (or
cut-out) located in the upper right-hand corner of the
plastic jacket (see figure 1-19). Whether or not the
write-protect notch is covered to protect the data on the
diskette depends solely on the disk drive manufacturer.
For example, on most systems using 5 1/4-inch
diameter diskettes, covering the write-protect notch
makes it impossible to write on the disk’s surface.
However, the opposite is true on systems using 3 1/2inch diameter diskettes. Uncovering the write-protect
notch makes writing impossible. In short, find out
which is which on your particular system before you
accidentally wipe out an entire diskette’s data.
Figure 1-21.—Internal hard disk drive mounted on disk drive
units that can be tucked away just about anywhere.
Generally, you will find them inside the system unit
(figure 1-21) in the space occupied by one of the floppy
Hard disk drives provide you with many
timesaving features not available nor possible with the
floppy disk drives. These include increased access
speeds, greater storage capacity (up to 8 gigabytes [GB]
of storage), and overall convenience. Working with
hard disk is much easier because you can quickly end
one program and start another, all through the operating
Floppy Disk Drives.— Floppy disk drives are
manufactured to read and write data in one of several bit
densities for both single- and double-sided diskettes. A
single-sided disk drive can only read a single-sided
diskette. However, a double-sided disk drive, like the
one shown in figure 1-20, can read both a single-sided
and a double-sided diskette.
DRIVES.— Although most microcomputer systems
you will be working on use some type of floppy disk
drive, you should also be aware that all micros also
contain a small sealed unit called a Winchester disk or
hard disk drive. Unless the disk drive is an external
type unit, you might never know it was there. Floppy
disk drives are easy to spot; all you have to look for is the
drive’s door, that open slot where you insert the diskette.
Hard disk drives, on the other hand, are normally sealed
Hard disk units consist of rigid metal platters that
are tiered or stacked. In most cases, the disks
themselves are not removable, and for this reason can be
hermetically sealed in the storage unit along with the
access mechanism that contains the read/write heads.
Because this type of disk drive is completely sealed and
free from air contamination, the read-write heads can be
positioned to within 20 millionths of an inch from the
surface of the disk. This also allows the disk to be
rotated at a high rate of speed-typically, 3600
revolutions per minute. Hard disks also comes in two
sizes (diameters): 5.25 inches, and 3.50 inches, with
3.50 being the most popular. Their storage capacities
range from 500 megabytes to 8 gigabytes, with the
majority in the 1.2- to 2-gigabyte range.
As mentioned earlier, hard disks can be placed
internally within the system unit, like the one shown in
figure 1-21, or externally as a detachable unit, as shown
in figure 1-22. You may have also noticed that the disk
drive shown in figure 1-22 is a portable hard drive in
that the hard disk is removable. The hard disks and
read/write mechanism are enclosed within a rugged
case. The result is a self-contained hard disk you can
insert like a floppy and remove for reasons of security.
Figure 1-20.—A floppy disk drive being removed from system
containing ink particles, the ink adheres to the charges
that form a pattern on the paper to develop the character.
This type of printer can be used for both printing and
plotting (displaying graphic output), and can print up to
5,000 lines per minute.
INK JET PRINTERS.— Ink jet printers employ a
technique very similar to the way we use a can of spray
paint and a stencil. A spray of electrically charged ink is
shot (under pressure) toward the paper. Before reaching
the paper, the ink is passed through an electrical field,
which forms the letters in a matrix form. The print
resulting from this process consists of easy to read,
high-quality characters. Some manufacturers use large
droplets of ink for faster printing, while others use small
droplets for better clarity but with slightly reduced
printing speeds. This type of printer can print up to 300
characters per second.
Figure 1-22.—External hard disk drive with removable disk
LASER PRINTERS.— Laser printers direct a
beam of light through a rotating disk containing the full
range of print characters. The appropriate character
image is directed onto photographic paper, which is
then put through a toner, developed, and used to make
additional copies. The print resulting from this process
consists of sharp, clean images that are easy on the eyes.
These printers can print up to 20,000 plus lines per
Most printers you are likely to use while working on
microcomputers are the low-speed varieties. They are
able to print text at rates of 200 to 800 characters per
second and usually output this information one
character-at-a-time. After close examination, you will
find that basically the only major difference between
printers designed for micros and those used on larger
mainframes is their size, and the speed at which they
print. Other than that, they are very much alike in terms
of setup, operation, and operational features.
Many micro printers can print subscripts and
superscripts, print in several different colors, print
graphic material, and output text in several different
type styles (fonts).
Micro printers, like mainframe printers, are either
impact or nonimpact. At least six printing technologies
are used to produce hundreds of microcomputer printer
models. These technologies include dot-matrix (which
forms characters using a series of dots), xerographic,
electrostatic, ink jet, and laser.
Some printers print in a single direction only, like
the conventional typewriter, whereas others print in
both directions (bidirectional) to save on timeconsuming carriage returns. Many come with either a
friction feed (for handling single-sheet paper) or an
adjustable tractor feed (for handling continuous forms),
and some even have both.
DOT-MATRIX PRINTER.— The dot-matrix
printer uses a print head made up of pins. It creates the
characters by using these pins to generate characters a
dot-at-a-time. Dot-matrix printers have speeds that
range from 60 to 350 cps.
printers use a printing technique very similar to the
methods used in duplicating or copying machines. The
printers can operate at speeds up to 4,000 lines per
You can initiate a wide range of printer functions
either through the applications program you are
working with or by using the controls located on the
front of the printer’s operating panel. These controls can
be buttons, lights, and switches. With a simple touch of
a button, you can change such things as type style, letter
quality, pitch, and spacing. It’s that simple.
printers use a special photographic paper that allows
characters to be etched onto the paper using a stylus.
The stylus, made up of tiny wires, forms characters by
placing an electrostatic charged image on the paper.
Then, as the paper is moved through a toner solution
As mentioned, most printers are equipped with an
operating control panel that allows you to change
various settings. For example, you can change the
number of characters per line or lines per inch, change
fonts and type size, and switch from draft to letterquality mode. You can choose any combination of
Figure 1-23.—Dot matrix printer showing operating control panel.
applications program. When in offline status,
the printer cannot receive data.
features quickly and easily. The printer we are using as
our example is a dot matrix printer (shown in figure
1-23). Dot matrix printers are widely used with
microcomputers in the workspaces. You will become
very familiar with their operation.
LINE-FEED (LF) BUTTON The line-feed
button allows you to advance the printer paper
one line at a time every time you press it. On
many printers, if you depress the line-feed button
for more than 5 seconds, the paper feeds
continuously line by line. Regardless of how this
button is used, the internal line counter is
incremented accordingly; therefore, the top-ofform position is never changed.
PANEL.— The operating control panel shown in figure
1-24 displays the buttons that control various functions
along with several indicator and warning lights that
show you what functions are currently in operation.
Listed below are some of the more common CONTROL
you are likely to see and use on this type of printer.
FORM-FEED (FF) BUTTON The form-feed
button allows you to advance the printer paper to
the top-of-form (TOF) position (the top of the
next page).
Control Buttons. —You can set up various
functions and control printing functions by manually
pushing control buttons. To activate the buttons, you
must first put the printer in an offline status. Normally,
this is done by depressing the online button.
the TOF button will advance the printer paper 1
1/2 inches and redefine the location of TOF on
the paper. On this particular printer, it will not
feed the paper to the TOF position, as it does on
many of the high-speed printers you have
ONLINE BUTTON The online button allows
you to put the printer in either online or offline
status. When in online status, the printer is under
the control of the operating system and
FONT BUTTON With the font button you can
select between fonts, depending upon job
requirements. If no selection is made, the
operating system normally defaults to the courier
PRINT MODE BUTTON The mode button
allows you to select the quality of print. This
Figure 1-24.—Printer operating control panel.
particular printer has two settings: draft mode
and letter-quality (LQ) mode.
PITCH BUTTON Use the pitch button to select
the number of characters to print per inch. This
particular printer has three settings: 10, 12, and
17 characters per inch.
Indicator and Warning Lights.— In looking at
figure 1-24, you will notice indicator lights located
above the control buttons on the control panel. They
provide status information and show the functions or
features currently in effect.
TAPE DRIVE.— You can use cartridge or cassette
tapes to provide backup to the hard drive. The tape drive
may be internal or external to the system unit. A tape
drive makes a good, reliable backup system for the
micro, since it holds 60MB or more of data. If a tape
drive is not available, you can backup to floppy disks.
POWER INDICATOR The power light lets
you know that power is being supplied to the
ONLINE INDICATOR The online indicator
tells you that the printer is in online status and is
ready to receive output from the microprocessor.
While it is in this status, normally, all other panel
buttons are inoperative.
OPTICAL SCANNER.— An optical scanner can
be used to scan (read) graphic art or text directly into the
microcomputer. This saves redrawing or retyping.
ERROR INDICATOR The error indicator
light warns you that there is a problem of some
sort that makes the printer inoperable. This
could be caused by a cover left open, the printer
out of paper, an electrical malfunction, a paper
jam, or possibly the font cartridge is not in place
or is improperly seated.
INDICATOR LIGHTS The lights located
above each button and next to each feature tell
you the current operating modes of the printer.
The lights are lit next to selected features.
Accessories and Other Hardware
In addition to monitors, disk drives, keyboards, and
printers, you may find a number of other attachments to
microcomputer systems. These might include a mouse
device, cassette tape drive, optical scanner, CD-ROM
drive, switch box, modem, and so on.
CD-ROM DRIVE.— You may have a CD-ROM
(compact disk-read only memory) drive to read data
stored on compact disks. CD-ROM technology is the
same as that used for audio disks, except it includes
routines for detection and correction of data errors. The
CD-ROM drive can be internal or external to the system
unit. Compact disks can hold a vast amount of
information, 550MB or more. They are used when the
same information is needed by many, and the
information is fairly constant. For example, libraries
can put all the information they need about documents
and publications on a CD-ROM. On a CD-ROM, the
MOUSE DEVICE.— You may have a mouse
device attached to your micro. It allows you to freehand
sketch or to select items from menus on the display
screen. As you move the mouse, the cursor moves to a
corresponding location on the display screen. For
example, if you are selecting an item from the menu,
you move the cursor to the item and press a button on the
mouse to select the item.
information, once recorded, cannot be erased or
changed, but it can be read many times. The expression
Write Once, Read Many (WORM) describes this type of
As you can see, a basic (low-end) system is only a
beginning. As you become more familiar with
microcomputers and as technology changes, you will
find more and more capabilities and more uses for
SWITCH BOXES.— When you want to share
printers, you can connect them through a switch or
switch box. For example, two or more computers can
use one printer, or one computer can use two or more
printers. As you can see, you will need a cable between
the switch box and each device. You then switch the
setting, A or B, on the box to switch signal lines without
disconnecting and reconnecting cables. Switches range
from this simple, manually operated switch box with
two settings to switches that select signal lines
automatically and provide buffering capability. Some
also provide for both parallel and serial devices.
Before you begin to set up or operate a
microcomputer, know what you are going to do.
THINK FIRST. Start with the documentation, NOT
with the hardware and software.
The first thing you will want to do when you install
or start using a system or a new software package is
become familiar with the documentation that comes
with it. You will also want to see what other
documentation and training materials are available.
Don’t get discouraged over the amount of reading
material provided to you. It takes time to learn
something new, and it takes practice to become
proficient. Spend time learning all you can about the
software and hardware. Refer to manuals and other help
aides when you have problems. You may also have inhouse user manuals to use.
MODEMS.— Modems provide communication
between systems. Through them, your system can send
or receive data over phone lines. You may also use a
null modem cable for communication between systems
that are close enough to each other to be connected by
cable. A null modem cable creates a communications
link that allows devices to communicate without using
modems and phone lines. To make the systems and null
modem cable fit together, you may need a gender
connector or gender changer to bridge two like
User/Owner Manuals
quickly navigate through all sorts of information in
connection with the applications program you are
using. In this example, it would be WordPerfect®. An
entire user’s manual and applicable documentation is
readily available to you with a couple of keystrokes.
Hypertext, which can include text, graphics, video, and
audio, is especially useful for users who do not have
access to manuals or when documentation is stored out
of reach.
User/owner manuals will tell you about the
hardware and how to install and configure it. Each
device will probably have its own owner’s manual. For
example: the printer’s manual will tell you how to
connect the printer to the system, how to insert the paper
and change a ribbon, how to use the tractor feed for
continuous-form paper, what the lights mean, what
settings you can change from the front operating panel,
and so on. The owner’s manual for the monitor will tell
you whether the monitor is monochrome or color, what
buttons and dials you can use to adjust the display, and
so on. The system owner’s manual will provide a
system overview. It will tell you how to unpack and set
up the system, how to power up the system, how to get
the software running, and so on. Disk operating
system and applications soft ware user manuals will
tell you how to install and use the programs. They will
also specify the hardware requirements: processor type,
memory size, hard disk needed, and so on.
Video, audio, or other online tutorial training
materials may be available at your command. For disk
operating systems that are in general use and for many
software packages, you can obtain text books, training
manuals, and supplementary manuals written by people
other than the vendor. Local bookstores and libraries
may have them.
Help Aides
Other help aides are help screens, keyboard
templates, and quick reference cards.
Most manuals that come with the system and
software will include sections with names like Getting
Started, Installation, Using the Software/
System/Commands, Reference, Error Messages, and
Troubleshooting. A learning or self-study section may
also be included. When you first begin, take the
appropriate manual and look at the headings in the table
of contents. Then browse through the appendices,
glossary, and index to become familiar with what they
contain. This will give you an idea of what information
you can find in the manual and how the information is
organized. For example, are the commands listed in a
reference section in alphabetic order, or are they
grouped by function in several sections? The more you
know about where to find information when you need it,
the more professional and confident you will be. One of
the most frequently used sections in the operators
manual is the section that covers the parameters. This
section includes the factory settings, the other settings
available, and how to change the settings.
Help screens are part of the program and can
usually be called on to the display screen at any
time while the program is running. This means if
you get stuck or confused about how to do some
function when you are in the middle of a task,
you can call the help screen function and have it
display information relating to your problem.
Reference cards usually list the features and the
keystrokes that activate each feature.
Keyboard templates fit over or above the keys.
They identify each feature and its associated
These aides are very helpful, especially when you
are jumping back and forth between a number of
different programs that have assigned different
meanings to the function keys. A quick look at a
template or a reference card, or a call for a help screen,
may be all you need to remind you of how something
works. This is especially true once you have become an
experienced user on a particular software package.
Training Materials and Aides
Software packages often include an online tutorial
on disk. If the package you are using has one, take time
to go through it. It will give you at least an overview of
what the software can do and how it works.
In-House User Manuals
To implement your own command’s policy and
procedures, you may have one or more in-house user
manuals. These will generally cover the use of
microcomputers, what software is to be used, any
specially designed routines and programs authorized
for use, standards for labeling diskettes and files,
The system may also have hypertext. Hypertext is
an online information system that can be incorporated
into a software package, such as WordPerfect®. It is a
data management program that allows you to very
backup procedures, maintenance procedures, security
procedures, and so on.
will tell you what cables belong to what equipment and
how to hook up the equipment properly. In the
following paragraphs, we will give you an idea of what
is involved when installing a microcomputer having a
separate monitor, keyboard, and printer.
Diagnostic/Troubleshooting Information
For performing diagnostics and for troubleshooting
problems, there may be separate manuals or the
information may be included in an appendix of an
owner/user manual. Become familiar with the kinds of
operator/user diagnostics you can perform. In this way,
you may be able to identify and isolate problems. Error
messages also provide information to help you solve
problems. Usually, an appendix or special section will
include a list with some explanation.
Most of the hardware components have built-in
system checks that occur when the particular piece of
equipment is powered on. If an error condition occurs
during the self test, an error code or message is
displayed. You will use this code or message to begin
the troubleshooting. Get the manual and look up the
error, this will give the cause of the problem and an
action to take to fix the problem and clear the error
There are several commercial
troubleshooting and information software packages
available to use in performing system checks, each of
which will include an operating manual on how to run
and interpret the results. Remember to use the
associated manual for whatever troubleshooting that
you do.
Normally, each device comes with its own power
line cable (except the keyboard, which gets its power
from the system unit). You plug each into an electrical
outlet. Be sure all power cables are polarized,
grounded, shielded, and have a three-conductor
grounding plug. This brings us to another very
important subject, power requirements.
Power Requirements
Most microcomputers can operate on voltages in
the range of 100 to 130 volts or 200 to 230 volts
alternating current (at). They are able to accommodate
either voltage through the use of a selectable switch
called a voltage or line select switch. The voltage
switch on our particular microcomputer is located on
the back panel of the system unit (see figure 1-25).
Once the computer components arrive, the first
thing that needs to be done is to inspect the components.
This is accomplished in several steps:
l Inspect the boxes for damage before opening
l After opening the box, check to be sure
everything is there (e.g., operating instructions,
cables, and cords).
Changing the voltage switch to a different
setting, say from 115 volts to 230 volts, would
also require that the power cable be changed.
Do NOT attempt to do this on your own;
instead, have it done by a qualified electrical
l Remove the components from the box, looking
for damage (e.g., cracks in the case, loose
connections, missing parts).
After checking over each component and making
sure everything is there, it is time to begin connecting
everything together.
If you’re not sure of the line voltage that is being
supplied to the electrical outlets in your work space,
have a qualified electrician check them for you.
Further, it is recommended that the outlet you select to
support your system be used only by the microcomputer
system and its peripheral devices.
The first thing you must do when setting up the
hardware is to read the installation instructions. They
Figure 1-27.—System unit (rear view).
with the flick of a single switch. There are many
varieties of surge protectors, and there is probably a
particular type already in use in your workspaces.
The System Unit
Figure 1-25.—Back panel of system unit showing voltage/line
select switch.
In looking at the back of the system unit shown in
figure 1-27, you will see a number of places called
connector slots to attach cables. Remember, this is just
an example. Each computer is different; refer to the
owners manual for exact locations of the connector
slots. You will also see the power cord connector. You
will need to connect the monitor, the keyboard, and the
printer to the back of the system unit. Before making
any type of electrical connections, be sure the ON/OFF
switch located on the surge protector is in the OFF
position and that the plug is removed from the wall
outlet. This doubly protects both you and the
equipment; you from being electrocuted, and the
equipment from being damaged.
Once you have determined that the type and amount
of power are sufficient to meet the microcomputer’s
needs, you must attempt to prevent abnormal power
fluctuations from damaging your microcomputer. With
alternating current, you have what are called peaks and
valleys. Valleys (also referred to as low voltage or
brownouts) will not harm the computer or any of its
related components. However, peaks (also referred to
as high voltage or surges) can overload and literally
burn up the computer’s internal components. You can
avoid these peaks/surges and protect the computer by
using a surge protector, like the one shown in figure
1-26. This particular surge protector has a power strip
capable of accommodating up to six components. It is
advisable to first plug the system unit and its supporting
devices into the surge protector, and then plug the surge
protector into the electrical outlet, as illustrated in figure
1-26. This lets you turn all your equipment ON or OFF
Connecting the Monitor
Located on the back of most monitors is an ac
power cable and a video input cable. You may also find
a voltage selection switch (for 115/220 vac operation).
Most monitors are designed to operate at either 115 or
220 volts ac, depending upon the setting of the voltage
selection switch (shown in figure 1-28). Normally, they
are preset at the factory for 115 vac operation. Should
Figure 1-26.—Surge protector with computer and peripherals
Figure 1-28.—Back of monitor.
your monitor have such a selection switch, be sure it is
set for the proper line voltage. Then, plug the power
cord into one of the receptacles on the power strip.
The video input cable has a twenty-five pin serial
connector. Plug it into SLOT H on the back panel of the
system unit, where the video display board happens to
be located on this particular unit (see figure 1-28).
Ensure that whenever you plug in a cable that it is
properly and firmly seated and tightened down if the
connector comes with screws.
Figure 1-30.—Cable connections from printer to system unit
and power strip.
Connecting the Keyboard
On the end of the keyboards cable is a five-pin
connector. Plug this into the back of the system unit to
allow for communication between the keyboard and the
system unit (see figure 1-29).
Configuring the System
Connecting the Printer
Like the monitor, the printer has its own power
cable and a data cable for communicating with the
system unit. Since most printers can operate in either
serial or parallel mode, it is important you look at the
data cable to see what type of connector you are
working with. Serial connectors are usually smaller
than parallel connectors and contain fewer pins. After
visually inspecting the data cable, connect it to the
appropriate printer connector on the back of the printer
(see figure 1-30). Should either the printer or data cable
connector have some type of locking device (screws or
cable locks), be sure to screw (or secure) them in place.
Then, connect the other end of the data cable to the back
of the system unit (slot D), as shown in figure 1-30.
Once you have made this connection, connect the power
cable to the back of the printer and plug it into the power
Once all of the hardware has been connected to the
system unit and has power, you are ready to start
configuring the system. In most cases, the system will
recognize the hardware that was connected and make
the changes on its own, but you need to know how to go
into the system configuration to make changes. Each
system has its own procedures to follow; so get the
manual and read about your system and how to make
To make changes you will need to get into the
system setup. Normally, this is accomplished by
pressing a key or series of keys when the system is
booting up. From system setup, the following changes
can be made:
. Date and time
. Memory size
. Floppy drives
l Hard disk type
All of this information is contained in the
complementary metal oxide semiconductor (CMOS)
chip. Since this is a memory chip, it requires a constant
source of power, a battery. The battery used most often
is a non-rechargeable lithium battery with a life
expectancy of 3 to 5 years.
Inspecting and Repairing Cables
Although inspecting and repairing computer cables
is not an everyday occurrence, you should know how to
perform these tasks. When it comes to inspecting
computer cables, there are several things to look for.
Some of these are:
Figure 1-29.—Cable connection from keyboard to system
be sent to another command. In either case, the
equipment must be packed up and shipped out. When
possible, use the original packing material, if available.
Otherwise, make sure the equipment is wrapped and
packed to avoid any damage. This can be accomplished
by using heavy cardboard boxes, bubble wrap, and
other cushioning packing material.
l Pinched cables
l Cut/broken cables
l Connectors/plugs pulled apart
l Bent pins
l Loose connections
Most of these problems can be avoided by taking your
time when installing the cables, avoiding setting
equipment on the cable, not pulling the cables, and
tightening the connectors down.
With the completion of this chapter, you should
gain a basic understanding of how digital computer
systems work. A computer system is composed of
hardware and software. Electronic digital computer
systems consist of a central processing unit (CPU) with
its primary storage and input/output (I/O) devices. The
arithmetic-logic unit and control unit process both data
and program instructions. Computers use stored
programs to process data and solve problems. This
provides a powerful method of automatic control. In
addition to operating microcomputer system, you
should become proficient at setting up, configuring,
upgrading, and initializing them. It is important that
you become familiar with computer system
documentation, including user manuals and any
software training materials and help aides. Among the
microcomputer-related tasks you will be expected to
perform are: inspecting, repairing, and installing cables;
running system checks; and troubleshooting error
The repairs that you will be expected to perform
most often are:
l Straightening bent pins
l Tightening the connections
l Replacing broken cables
You will not be expected to repin a cable, since the
equipment to perform this operation is very expensive.
It is cheaper and easier to just replace the cable when it is
determined that the cable is bad.
Preparing the Computer for Shipment
From time to time, you will be expected to prepare a
computer for shipping out of the command. This occurs
when a piece of equipment has to be returned to the
manufacturer for some reason, or if the computer has to
Upon completing this chapter, you should be able to do the following:
l Explain the use of trouble reports.
l Describe how to output and inspect data from a computer system.
l Explain the importance of maintaining optimal environmental conditions.
l Explain how to use the computer console to query and monitor the system.
l Describe virus protection software.
l Explain the use of AIS requests.
l State the procedures used in the media library to store and maintain media
and transfer data.
l Identify procedures used for storage media destruction.
l Discuss administrative duties in a media library.
l Explain how to create, modify, delete, backup, and restore system directories
and data files.
l Describe the system processes for performing system backups, executing
application utility programs, and running batch jobs.
implementing performance-tuning initiatives to
improve computer system performance. You will be
evaluating and maintaining user manuals. All these are
technical functions needed to ensure the smooth
operation of an AIS facility.
You, as the computer operator, are an extremely
important individual within your automated
information system (AIS) organization. It is your
efficiency (performing in the best possible and least
wasteful manner) and your knowledge (knowing and
understanding the theory, principles, and facts, coupled
with experience) that help ensure the overall
effectiveness of the AIS installation. You must be
familiar with the various methods of controlling data
and procedures. You must also know the operating
steps and procedures of your assigned computer system.
You will be responsible for submitting trouble
reports, as discussed in chapter 1 of Module 1. Trouble
reports are used in reporting any system problem
involving hardware or software that you cannot correct.
Remember, the report must be as complete as possible.
Technical administration and support are important
aspects of AIS facility management. You will be
making hardware and software projection reports,
software performance reports, hardware utilization
reports, and trouble reports. You will be responsible for
If, during the course of checking over the user’s
output, you happen to come across something unusual
or you find an error, by all means pull (reject) the job
immediately, bring it to the attention of your superior,
and notify the user of the delay. Even at this late stage, it
is better to reject a job to correct any problems or
discrepancies rather than release it, only to have it
returned for rerun later.
Output from computer processing, the work that
has been completed, may take the form of a printed
document, magnetic tape, or magnetic disk or diskette.
In all cases, you are responsible for and must ensure that
all completed jobs run successfully. In addition, you are
responsible for identifying and coordinating the various
outputs for each job, and for initiating their correct
You work in air-conditioned environments that
other AIS personnel (programmers, analysts, and so on)
would probably consider intolerable. The coolness of
the computer room or center is a constant source of
discomfort. Computer rooms have to be kept at a
constant and fairly cool temperature to ensure ideal
operating conditions and prevent equipment failures.
The humidity must also be controlled, for the protection
of the equipment and storage media. This is
accomplished by some sort of dehumidifier system.
Although the requirements usually call for 70°F to 74°F,
temperatures often range from 65°F to 70°F, and the
humidity ranges between 30 to 60 percent. Fortunately
for us, most minicomputers and microcomputers
generate far less heat and humidity than mainframes
during operation and, as a result, require only a minimal
amount of cool air.
To determine whether a job (or system) ran
successfully (to a normal EOJ) and that all processing
steps were properly performed, you may have to review
the computer console printout. This printout indicates
such things as the number of input records read, the
various input files updated, all error conditions (error
messages) that the operator encountered during the run,
and the resulting actions taken, the various output files
created, and so on.
Most of the time, the computer console printout will
provide you with the answers you are looking for when
it comes to reconciling processing discrepancies. For
example, it will inform you of the reasons certain output
products, tapes, diskettes, or report listings, were not
produced. Possibly the operator selected an incorrect
program option, or the input parameters were incorrect
or incomplete before starting the job. In short, you are
responsible and also accountable for every job you
work on, from the time it is submitted by the user until
its delivery back to the user.
You will be using a hypothermagraph to monitor the
temperature and humidity of the computer room. There
are several different models and styles of
hypothermagraphs, each with its own specific operating
requirements. Check the operator’s manual for the
specifics of your equipment. The hypothermagraph
uses a paper chart and marking pens to record the
temperature and humidity. The chart is normally a
7-day graph showing the day and a number range. It
uses two different colors, usually red for humidity and
blue for temperature, to show the temperature and
humidity on the chart.
When checking the user’s output, you should once
again refer to the run sheet and/or task folder to verify
that all items requested were, in fact, produced. If the
output is in the form of magnetic tape, disk, or diskette,
be sure it is labeled properly, given the proper
classification, and it is on the appropriate media
(magnetic media that has been designated for mail-out
or distribution only).
When checking reports, make sure that they were
run on the proper forms (size and type), that no pages are
missing and the correct number of copies were printed,
and that all print is legible and lined up properly.
CPUs aren’t the computers you may have seen in the
movies with all the blinking lights, although their basic
functional units are still the same. The CPU of today,
regardless of its size, still contains an arithmetic-logic
section, a control section, and an internal storage
(memory) section, as we discussed in chapter 1.
However, today’s CPU contains relatively fewer lights,
switches, levers, and dials when compared to earlier
models. So you may be thinking, but aren’t all these
Once it is completed, you then package each copy
of the report, along with any other output products and
the original input, place it in the proper pickup area, and
log the job out in the job control log. You may need to
notify the user when the job is ready.
Each system has a language designed to interact
with the user’s application program and the computer’s
operating system. These languages consist of control
statements that are placed directly before the user’s
program to direct the operating system in its functions.
The format of the control language statements differs
greatly from one system to another. You will learn the
specific control language used on your computer on the
job. In addition to console-related functions, you must
maintain records required to supplement the console
log, including problem documentation and actions that
were taken, computer utilization logs, file
identification, and so on.
bells, whistles, and lights necessary so that I can
communicate with the CPU and its peripheral devices?
They really aren’t.
At one time, systems like the IBM 360 series were
characterized by dials, switches, and lights that
flickered on and off. And although most of the switches
and lights were primarily used by the maintenance
technician or customer engineer, an experienced
computer operator could tell you the status of the system
just by watching the movement of the lights. These
operators were able to detect when a program was in a
loop, when a peripheral device became disabled, or
when the CPU went into await state. The operator used
some switches to manipulate the logic of the program or
to enter data into the system; other switches and dials to
display the contents of registers or data stored within
main memory; and still other switches to perform
special functions, such as single-cycling the computer
through the instructions of a program.
Console Keyboard
The standard keyboard has the same alphabetic key
arrangement as a typewriter with a 10-key numeric
keypad to the right, with special function keys located
on both sides of the alphabetic keyboard. The special
function keys differ, depending upon the console
keyboard. The function keys are usually a different
color from the alphabetic and numeric keys. By
providing you with special function keys, the
manufacturer has made it easier and faster for you to
perform routine functions. Depending upon the
software being used, some console keyboards use the
top row of keys (0-9) as command function keys. The
command keys cause such functions as automatic skip,
enter, update, move, copy, end of job (EOJ), delete. The
operator’s guide usually provides documentation
regarding each of the function keys. For the most part,
console keyboard operations are relatively easy.
Prompts are often displayed to help you in responding to
messages, initiating jobs, and entering commands and
Today, the communications mode between the
operator and the CPU differs considerably from those
earlier systems. We know the computer can
communicate far more effectively with the operator
(that’s YOU) through a CRT and console printer than it
does through lights or display panels. Now, you are able
to communicate with the computer by entering the
necessary responses through the keyboard of the
Depending on the size of the computer system you
are assigned to, there may be one or more system
consoles used to monitor the system. The consoles
include a CRT and a keyboard, and may have a console
printer. As a console operator, you are ultimately
responsible for controlling the entire system. You are
responsible for initial program loading (IPLing) or
booting the system; starting jobs; monitoring jobs;
responding to messages; and, most importantly, making
decisions and taking care of any problems that may arise
with regard to hardware and software. You are also
responsible for directing the activities of peripheral
equipment operators to ensure accurate response to
job/run stream requirements. You are constantly
monitoring system operations to determine whether
programs appear to be operating correctly. You must be
familiar with and know how to use the various types of
control languages and statements that are used with
Configuration Changes
Computer system configuration changes take the
form of both hardware and software changes. The
addition of new hardware and software upgrades will
affect how you do your job.
HARDWARE.— Changes to system hardware
include the addition of new, the loss of existing, and the
modification of existing peripheral equipment. You, as
the computer operator, may be involved with helping to
move the equipment, running cables, or removing
cables, but the majority of the work is usually
performed by maintenance technicians.
SOFTWARE.— Changes to the software include
changing memory, buffer sizes, and hardware
addresses; and adding new application software.
Changes to memory, buffer size, and hardware
addresses require changes to the operating system. In
addition, you must follow the manufacturer’s
instructions. Memory and buffer size changes are done
when system performance has dropped because of
increased use or changes to peripherals. By increasing
memory and buffer sizes, the throughput time of the
system is improved and the user access time is
shortened. Hardware addresses are changed when there
is a change to hardware status, such as the addition or
loss of a piece of equipment. The addition of new
application software will cause the system to be
unavailable to users during the implementation. When
the software arrives, it will include the installation
instructions that are to be followed.
anyone, even someone unfamiliar with the system,
could follow the step-by-step directions.
Computer Diagnostics
Computer diagnostics are of two types: those that
are run when the computer is booted (called internal
diagnostics), and those that can be run from a peripheral
device (called external diagnostics).
diagnostics are performed when the computer is booted
and are designed to test the computer hardware. They
return a pass/fail result to the operator. Some of the
internal diagnostics are designed to test all or selected
sections of the computer. An example of an internal
diagnostic test is the power on-self test (POST), that
checks the components upon power on.
Powering Up the Computer
diagnostics can be loaded into the computer from a
peripheral (disk or magnetic tape unit) but initiated and
controlled by the computer. These diagnostics are very
thorough and offer the option of testing all or specific
sections of a computer. They are more comprehensive
than the internal diagnostics.
The CPU is normally powered up first; then one by
one, each of the I/O devices is turned on. This is done to
prevent a sudden surge of power that might overload the
circuits. With the computer system powered up, you
can then proceed to IPL the system.
Booting the System
Anytime the system loses power, is shut down, or
becomes disabled because of a system crash, it usually
needs to be rebooted or initial program loaded (IPLed).
A system crash is the result of a hardware, software, or
operation problem: a malfunction in the CPU, a
programming error from which the operating system
could not recover, or an operator error caused by an
incorrect response to a message. Booting most systems
resets all status indicators and reloads the supervisor
(the executive-system program along with other
resident routines) into the CPU memory. The manner in
which the system is booted depends upon the computer
system used and the software included in its operating
system. Many of the larger mainframe computers store
their operating systems on disk, and this disk is referred
to as the SYStem RESident (SYSRES) pack. Once the
disk unit with the SYSRES pack is in a ready status, you
can then boot the system. Some systems are so simple to
boot that all you need do is depress the start (or load)
button on the CPU (or master console) and enter the date
and time on the console keyboard. Some of the more
complex systems may require you to take additional
steps—assigning various I/O devices, partitioning
(sectioning off) memory, and so on. It is because of
these differences that boot procedures are well
documented with each step explained to the point that
Unless you respond correctly to a system- or
program-generated message, CPU time can be lost, the
wrong program options can be executed, and the system
can even become disabled. As a console operator, you
are the most important part of a team effort that makes
computerized procedures successful. It is true that while
complex operating systems make it easier for you to
perform various tasks, correct responses to messages
are just as critical. Never second-guess a response.
Always refer to the proper documentation to determine
the response needed. Manuals provided by the
manufacturer, operator’s manuals, and error message
manuals should be located as near to the console as
possible for your convenience.
Basically, you will be concerned with two types of
messages: system-generated messages and programgenerated messages.
System-Generated Messages
System messages are generated by the operating
system software. To be more specific, it is the
executive-program (the supervisor) that is responsible
for monitoring and allocating the resources of the
system, and also for communicating with you, the
common application utility programs that you will run
will be tape and disk copies, to make backup copies of
application files.
While carrying out the instructions of an
applications program or a utility program, the computer
is in a program or problem state. While in this state,
interrupts occur that return control of the system
resources to the supervisor. When this occurs, the
computer is in the supervisor or control state.
While batch jobs are more detailed when it comes to
starting them, as long as the run folder is followed there
will be no problems. They will have different inputs and
outputs required than utility programs. All of the file
names and media types will be supplied by the user in
the form of an AIS service request. Remember, before
starting either an application utility or a batch job, look
at and follow the operator’s manual and run folder for
the job.
When an interrupt occurs, a message to the console
operator may be displayed to indicate either a normal or
abnormal condition. Some messages require a response
on your part; others do not. “File XXX now being
loaded,” or “PAYROLL1 completed (EOJ)” do not
require a response. Other messages, like “Printer Not
Ready,” or “No volume label found on pack XXX999,”
or “Insufficient memory allocated for job XXX” do
require a response on your part.
Using the system console, you can display, by their
assigned name, the status of all jobs that are currently
being executed. The job status also indicates whether
the job is active, stopped, terminated, or canceled but
still residing in the CPU; waiting for space in the work
area or on disk; waiting for a printer or a
communications line; or waiting for you to respond to a
message. You can also display the status of the system’s
I/O devices to see whether or not they have been varied
offline to the system.
You may be asking yourself, how do I know what
occurred, and how do I respond to a system-generated
messages are coded, and you use this code to lookup the
meaning of the message displayed. These types of
messages are normally found in the software manuals
supplied by the manufacturer. As you become more
experienced, you will quickly become familiar with the
different types of messages and be able to determine the
origin of the message just by looking at the identifying
One of your primary responsibilities is to maintain
an awareness of the jobs currently undergoing
processing within the system. Having the above
information is extremely important to you, as it enables
you to provide services to the various jobs being
processed. The jobs with the highest priorities usually
receive immediate attention. Jobs with lower but equal
priorities are processed in the order they were entered
(loaded) into the system (first-come first-served).
Program-Generated Messages
Program-generated messages are those messages
that are displayed by the program as the result of the
programmer wanting to inform you of an available
option or wanting you to supply data. The program
might display a message such as “Enter expiration
date,” or “Option 1 to edit data, Option 2 to update file,”
or “Load four-part paper in printer.”
Considering these operating constraints, it is easy to
understand why the system is in a continuous state of
change. Through the use of the display command, you
are able to get an immediate picture of the system’s
activities. Using this information as a frame of
reference, you can determine what actions are necessary
to maintain a continuous work flow.
Whenever a program message is displayed that
requires a response, the run book/sheet along with the
documentation (operator’s manual, run manual)
provided by the programmer should explain each and
every response or option available and how you are to
Unfortunately for us, not all jobs processed come to
a normal end of job (EOJ). Things like program or
machine interrupts, operator errors, bad input data, and
incorrect responses to messages can cause a job to
prematurely or abnormally terminate (ABORT). When
this occurs, it is imperative that normal operations be
resumed as quickly as possible. Error recovery must be
As an operator, you will be expected to run utility
programs and batch jobs. The start up procedures are
similar for both; refer to the operator’s manuals and run
folders for the specifics for each job you run. The most
accomplished to maintain production schedules and
minimize cost and lost computer time.
By monitoring the console (CRT or console
printer), you can determine whether a job aborted
because of invalid data or during processing. On some
systems, the operating system software will display on
the console the reason for the job’s cancellation or the
point at which the abort of the program took place. If the
job aborted during the input phase, you may conclude
that bad input data was at fault. If the input data was
accepted and processing begun, you may conclude that
a program malfunction was encountered (barring any
hardware problems) and caused the job to be
automatically flushed (canceled) from the system.
Among the tasks you may be asked to initiate via
the console is cancellation of a job currently running
within the system. The purpose of the cancel operation
is to allow you to halt (stop) the processing of an
application program and remove it from the system. A
program can be canceled by either the supervisor
control program or by you. Should the supervisor
control program determine that an application program
is not executable, it automatically directs the computer
to cancel the program and, thereby, halt its processing.
There are times when you must intervene with normal
processing and flush a job from the system even though
the program being executed may not have an error in it.
For example, you could be instructed to process a higher
priority job immediately. Unable to wait for the
completion of the current program (job), you are,
therefore, required to abort it. Don’t become confused
over the terms cancel, flush, or abort; they all have the
same meaning. You may also be required to cancel a job
because it has entered a continuous loop, been running
way beyond the allotted time, or because it is trying to
access a restricted file. You will find that there are many
such reasons for having to cancel a program. There are
times when you will cancel a program or a program will
abnormally terminate (ABEND). This will require you
to dump (print out) the contents of storage. This is
known as a post-mortem dump. The system prints the
contents of all the storage areas used by the program in
the processing. This post-mortem dump is used as a
debugging aid to help the programmer analyze the
Regardless of why the job aborted, ultimately, you
are responsible for initiating recovery from the job
cancellation, using one of a number of methods. In
many cases, the operator’s manual or run manual will
provide you with the proper procedures necessary to
recover or restart a job. One method is to rerun the
entire job. However, this could be very costly and time
consuming, especially if the master file(s) had to be
returned to its/their original state. You might have to
recreate files from backup files and rerun programs that
added, changed, and deleted records. This problem is
especially true when working with disk files.
When the operating system supports checkpoint
restart routines, a job can be restarted near the point
where the problem occurred without having to rerun the
entire job (or system). The logical point to take a
checkpoint is at the end of reading or writing a tape file
or after a predetermined number of records (say,
15,000) have been processed, or after so many minutes
of processing (say, 30 minutes) have occurred. The
programmer determines the points in the program at
which the checkpoints are to occur. This way, if the
program cancels (aborts), it can be started again at the
last checkpoint.
Whenever a job is canceled or abnormally
terminates, it is your responsibility to make an entry in
the error/trouble log, giving the cause of the problem
and as much detail as possible.
Documentation, who needs it? In data processing,
we all do: for without it, we would quickly find
ourselves in serious trouble. As a computer operator, if
you want to know how to run a particular procedure,
job, or system or learn more about a particular
procedure, job, or system, the operator’s manual or run
manual is a good place to start. It can provide you with a
wealth of information. Examples are a written
overview of the system and systems flowchart, in-depth
coverage pertaining to I/O requirements, file
specifications (layouts), processing methods, job setup,
error messages that might be generated,
Even if the system provides for an automatic restart
at the last good checkpoint, you still must authorize the
restart. Usually, a message will appear on the console
indicating the job (or task) to be executed and the
checkpoint for restarting the job. It is then up to you to
either restart the job, postpone the restart until the cause
of the problem can be determined, or indicate that the
job is not to be restarted. Under no circumstances
should the termination or cancellation of a job interfere
with the continuous flow of processing within the
recovery/restart procedures, and sample reports. As the
console operator, you are responsible for running
hundreds, possibly even thousands, of jobs on a regular
basis. Without using the available documentation, even
an experienced operator cannot understand or be
expected to remember exactly how each job is to be set
up and run.
that the next job to be processed will be input to the
computer system with minimum or no delay. In
determining all these factors, you get a feel for what’s
going on and what is to take place during the upcoming
shift—your shift.
In a production environment, personnel sometimes
get too busy to finish a job or job step. Take that little
extra time to stay organized, especially when it comes to
the paperwork. Keep in mind and help other personnel
understand the importance of being organized, and the
problems that come from having too many things going
on at one time. A misfiled or mislabeled tape can, at
best, mean lost time either in locating it or recreating it.
At worst, it can mean lost data and an unrecoverable
The actual format of the operator’s documentation
differs, depending on your installation’s requirements
and SOPS. In some installations, you will find that each
procedure or job has its own folder or notebook. Other
installations may include an entire system (several
jobs), such as personnel or payroll, in one large
notebook. Regardless of how the documentation is
formatted, its basic objectives are to provide you with
complete instructions and to serve as a ready reference.
So take the time to read the documentation. You will
find that from knowledge comes the wisdom to make
the right choice or the right decision every time.
You will find that most AIS installations overlap
each of the shifts from 15 to 30 minutes. This allows
you sufficient time to get acquainted with the jobs
currently being run and provides continuity between
shifts and operators.
As you have probably realized by now, you have the
prime responsibility for keeping the computer in an
operational state. That is, you are responsible for the
continuous and efficient processing of all types of
program applications. Knowing this, it is essential that
you acquaint yourself with the status of the system
before working on the shift, whether it be on the day
shift, eve shift, or mid shift. Before you assume control
of the shift, you should be aware of its operational state.
Normally, this information is obtained from the
operators currently on duty, the shift supervisor, the
various computer logs and run schedules, and by
monitoring the activities of the system. In essence, you
must examine those indicators that can reveal possible
trouble spots or system malfunctions. For example, ask,
what maintenance activities were accomplished, if any,
on the previous shift(s)? what devices (pieces of
equipment) have been varied offline (those devices
which are not available to the CPU)? what other devices
have not been fully operable? what maintenance
activities, if any, are scheduled during your shift? and
are any applications scheduled that are normally
troublesome, difficult to handle, or prone to producing
errors? Then ask about the work to be done on your
shift, what jobs are scheduled to be run? are all the
tapes, disks, documentation, and other various media
and supplies present and accounted for? if not, have the
appropriate personnel or organizations been
notified-the librarian, data entry, or scheduling—to
rectify the problem? This is important, for it ensures you
Throughout this section, we have tried to make one
point clear: you must learn to react quickly to situations
that may affect the processing capabilities of the
computer system. To accomplish this task, you must
have a working knowledge of the operational aspects of
your job. That is, you must understand what procedures
to follow when specific errors arise, know where the
operations manuals are kept and how to use them, know
where the supplies to process jobs are stored (computer
ribbons, paper, tape reflectors, and so on), who to
contact in the event of equipment or program failures
and errors, and what forms are used and for what
purpose. Having a general knowledge of what to do is
particularly important to you as a new operator just
reporting aboard. You must adjust yourself to this new
environment and learn where things are located as well
as what should be done.
Regardless of the system you are working on, you
must know how to use all the available resources, which
include hardware, software, and people. Operators who
are alert to the requirements of the total system and are
able to understand and use the available resources play a
vital role in the overall efficiency of the system, the
department, and the installation. It is your performance
as a computer operator that often determines the general
attitude of users toward your installation. In developing
a proper attitude toward your work, adhere to a code of
Job Monitoring
Viruses take advantage of the sequential step-by-step
process that the computer follows. The virus is read into
the computer via a peripheral device (tape drive,
diskette drive, communication device, and soon) from a
previously infected software application. The virus
then inspects the first few instructions of each program
until it finds a program that does not begin with the same
instructions as itself. Then it attaches a copy of its own
instruction set to the front of the program being
examined. The spread of the virus comes from
inspecting and duplicating itself. Execution of
programs may seem to appear normal until the virus
strikes. A virus can destroy data files and programs,
depending on its design. Be particularly careful about
putting new software on your computer; if it contains a
virus, it can infect your other programs and data, giving
you big problems. Your ISSO and Naval Computer
Incident Response Team (NAVCIRT) can assist you in
the detection and eradication of the virus.
Although we would like to believe all jobs run
without error, there are occasions when a program
prematurely or abnormally terminates. It does not
process to normal end of job (EOJ). When this occurs,
the operator is expected to take whatever corrective
actions are necessary to get the job going again. More
often than not, the operator is able to recover a job by
recreating a tape/disk file, moving the file to another
device, or possibly cleaning the read/write mechanisms
of the device prior to rerun. But, there are times when
the operator will notify the I/O control clerk to assist in
correcting the problem. Such would be the case when
the input parameters are in error, the user’s input is bad,
or the job aborted because of an unrecoverable program
error. In the event this happens, you maybe responsible
for collecting all the data, both input and output, along
with any memory dumps, and forwarding them all to the
Processing AIS Service Requests
During the recovery phase of an operation, the
operator may need you to provide certain input
parameters or tape/disk files before the job can be
executed. Because of time constraints, a job that
abnormally terminates may have to be rescheduled. If
so, you may be responsible for seeing to it that the job
gets rescheduled and that the user is notified of any job
delay. We could go on and on, but by now you are
beginning to get the picture. These examples are just a
few of the many things that can get in the way of
achieving a normal EOJ. We bring them to your
attention to make you aware of the types of problems
that can and do arise, and the manner in which you are to
respond. Hopefully, you now know and are aware that
monitoring a job means more than just calling up the
operator to see how the job is progressing. It means you
must oversee the job to its completion, doing whatever
is necessary to help keep the job (or system) on track.
Your first task may be to receive jobs from users.
Each job will have an AIS service request of some type.
A typical AIS service request is illustrated in chapter 1
of Module 1 (figure 1-2). In looking over this form, you
will notice that it provides you with all the information
needed to run the job.
As a librarian, your job encompasses many duties
and tasks vital to the smooth operation within your
installation. Usually, you will find that there are
instructions and/or standard operating procedures
(SOPS) to help guide you along in different areas of
library procedure and toward establishing a highly
functional library.
But what about you? What should you know or be
aware of when working in the AIS media library? The
answer to that question is the topic of our discussion:
library functions. Put briefly, as a librarian, your job is
to become as proficient as possible in the different areas
of library management, by learning all the ins and outs,
you might say. You will need to know how to receive,
handle, maintain (condition, clean, and retire), store,
issue, and transfer magnetic media. You will be
working with a minimum of supervision and will have
to work well with other people to provide the needed
services in a timely manner.
Virus Utilities
Virus utilities keep out viruses (malicious logic)
that can attack computer system software. This type of
software is normally designed to prevent both “known
and unknown viruses” from invading a system, and
detects and removes those already present. What is a
virus? you might ask.
A virus is a self replicating, malicious program
segment that attaches itself to an application program or
other executable system component and leaves no
obvious signs of its presence.
And just like any
bacterial disease, it can spread from disk to disk.
As the AIS librarian, you can be expected to
perform any one, several, or all of the following tasks:
. Have a standard operating procedure (SOP)
instruction manual, indicating all library procedures,
readily available.
. Keep an adequate supply of magnetic media
(scratch tapes, initialized disk packs, diskettes, and
cassettes) available in the library and/or in the computer
area ready for use.
. Retrieve and file magnetic media in accordance
with command policy.
. Have an adequate supply of save (external)
labels and classification labels available for the
computer operators.
l Maintain a current inventory of all magnetic
Control tapes (save tapes, work tapes, and
scratch tapes) on a rotational basis.
Q Check all user submitted save labels with job/run
request sheets to ensure they are correct.
l Test tapes for quality, and clean and degauss
tapes and disks according to prearranged schedules or
upon release by programmers and in-house users.
. Check save labels to ensure they indicate no
more than a 90-day save request, and that only one 90day extension is granted before the tape is copied to
another tape.
. Ensure that all magnetic media is acclimated to
the atmosphere in which it will be used for at least 24
hours before releasing it for use.
. Inspect new tapes and install BOT and EOT
reflectors if not provided by the manufacturer.
. Ensure all users annotate, initial, and return their
weekly copy of the release report, indicating what tapes
are to be scratched, cleaned, degaussed, stripped, or
mailed off-site; or any other action they deem
. File newly created tapes after checking the
identification tape reel number against the tape strap
number (if used) and verifying that the security
classification on the label matches that on the tape reel.
. Collect a copy of the save labels from the
operators for the tape library tape/disk database file
(only if the site has an automated tape library control
system) and supported software.
. Refile previously created tapes, being careful to
scrutinize each as if it were a newly created tape.
. Maintain off-site storage of tapes and disks for
disaster recovery.
. Strip tapes (by removing the first 100 feet) when
the error rate increases and replace the beginning-oftape (BOT) reflector. If a tape has damage to its end,
remove the last 100 feet and replace the end-of-tape
(EOT) reflector.
. Maintain a current list of all foreign (outside)
tapes and disks received and return them on schedule.
. Ensure fire-fighting equipment in the library is
maintained and inspected by appropriate personnel (fire
department, damage control petty officer, and so on) in
accordance with command policy.
. Keep all system tapes and disks in good
condition at all times.
. Update fire-fighting instructions as necessary.
l Maintain a record of tapes and disks that have
been cleaned by stamping the Julian date on a cleaning
label on the back surface of the tape reel or disk pack
. Maintain the correct temperature and humidity
in the library.
. Maintain security requirements and access to the
library area.
. Clean disk pack covers according to schedule or
as the need arises.
. Ensure unauthorized persons do not remove
magnetic media or related materials from the library.
l Maintain and distribute tape and disk error and
usage reports.
. Maintain control of certain required data files,
program files, and various types of microforms
. Promptly report any and all problems to your
supervisor, leading chief, or other appropriate
personnel in accordance with standard operating
procedures (SOPS).
l File all library materials in a neat, organized, and
uniform manner.
As you see by this list, there is a lot to do. In anyone
day, you may perform one or many of these tasks.
Practice being a good communicator, and adopt orderly
work habits.
One of your jobs will be to receive magnetic media
from the manufacturer (new tapes, disks, or diskettes).
The first thing you should do is check the shipping
container for obvious damage, such as crushed corners,
holes, and the like, as shown in figure 2-1. If you find
obvious damage, closely examine the media to
determine whether damage has occurred. In case of
damage, the affected media must be disposed of in
accordance with command policy or contract
Physically check magnetic tapes for damage. Get in
the habit of looking for such things as broken or warped
flanges and damage to the outer edges of the reel. Also,
check for damage to the wrap-around strap (see figure 2-2).
Examine disk packs for broken or cracked dust covers (see
figure 2-3). In addition, visually inspect each and every disk
surface for physical damage and warpage. Also, check the
air filter located on the bottom spindle of the pack to ensure
that it is in place and correctly inserted (mounted).
Figure 2-2.—Damaged wrap-around strap.
new does not necessarily mean good. If a tape cleaner or
certifier is not available, you may be able to use the
computer to check out the tape. Some computer systems
have software programs that will allow you to test a tape
while it is on the tape drive. However, to use this
method, you must be allocated computer processing
When you examine tapes, check to ensure that
reflective tape markers, the beginning-of-tape (BOT)
marker, and end-of-tape (EOT) marker are physically
located and properly placed at the beginning and at the
end of the tape. Should your command have a tape
cleaner or tape cleaner/certifier similar to the one shown
in figure 2-4, by all means use it to check out the
placement of the reflectors as well as to ensure that
nothing is internally wrong with the tape. Remember,
Before releasing magnetic media from the library for
use on the computer, you must ensure that the media has
been properly labeled and prepared (prepped).
We use two types of labels for magnetic media. The
first type is placed on the outside of the media itself and
Figure 2-3.—Damaged disk dust cover.
Figure 2-1.—A damaged tape shipping container.
Figure 2-4.—Checking for BOT and EOT with read/write head.
is referred to as an external label. External labels are
the labels we are interested in. The second type is
written directly onto the media and is referred to as
an internal label. Internal labels contain information
that is needed by the executive control programs
(systems software) of the computer to allow for the
proper functioning of applications programs.
files that are contained on the media. As the magnetic
media librarian, you are responsible for initiating and
maintaining the first four types of external labels:
identification, certification, usage, and cleaning
External Labels
External labels are considered permanent or
nonpermanent, depending on their purpose (see
figure 2-5). The two types of permanent tape and
disk labels are the identification label, which
indicates the number that has been assigned to the
media; and the certification label, which indicates
the last time the media was certified (tested for its
reading and writing capability). Nonpermanent
labels include usage labels to tell you how often the
media has been used on the computer, cleaning
labels to indicate when and how often the media has
been cleaned, and save labels to indicate the file or
labels. The programmer, user, or control clerk is
responsible for the save label.
a cleaning, and that is where you come in. Every time a
tape is returned to the library, you should make it a point
to check the usage label to see whether or not it requires
cleaning. A magnetic tape maybe cleaned at any time.
However, if the tape does contain live data (data still
needed), try to be extra careful not to damage the tape
during the cleaning process. Normal operating
conditions in the computer room require the read/write
heads to be cleaned at least once every 4 hours of
operation and the entire unit once every 8 hours unless
usage is very heavy or as specified in the SOP. If this is
done, a tape should be cleaned after every 5 uses, and
the number of uses between cleanings should never
exceed 10.
PERMANENT LABELS.— The permanent-type
label comes with a special adhesive backing; and when
applied to a surface such as the flange of a magnetic
tape, it adheres permanently. That is not to say this type
of label cannot be removed, but to remove it takes a
considerable amount of effort. Normally, you would
consider using this type of label only if it were to remain
on the media throughout its life cycle, as is the case with
the identification number or certification labels.
Identification Label.— The identification number
(label) contains a series of letters and/or numbers
(usually from 3 to 8 characters in length) that tell you
where the magnetic media resides in the library (see
figure 2-5). It is a permanent home address, you might
say. Your responsibility is to ensure that whenever new
tapes and disks are brought into the library be properly
numbered. If the tape or disk is a replacement for one
that is no longer usable, you must be sure to dispose of
the old media and physically remove the identification
Cleaning Label.— The cleaning label is used to
indicate when and how often a tape has been cleaned.
This is important to know, for after a tape has undergone
so many cleanings (usually 10), it should be put through
a certification process to determine its accuracy
(reading and writing capability). Normally, you place
the cleaning label on the backside of the tape, since the
information it contains is useful only to you, the
Certification Label.— The certification label is
used to indicate the last time a magnetic tape or disk
underwent certification. Diskettes are not normally
certified, but, instead, are disposed of upon receiving an
unacceptable number of unrecoverable read/write
errors. It has been found to be more cost effective to
simply replace this type of media with new rather than
putting it through a refurbishing process.
Save Label.— Whenever a tape is to be saved for a
period of time, a save label, such as the one shown in
figure 2-6, is required for accountability. The save label
(also referred to as a user label) contains information
that helps to identify the job/task number and the data
file(s) written on the media, along with other related
information. This label is placed on the front side of the
media so it can be readily seen by all. Each individual
programmer, user, and, in some cases, the control clerk
(depending upon command policy) has responsibility
for filling out as much information on the save label as
possible before job submission. He or she normally
enters such information as: job or task number, file
identification, security classification, purge date, and/or
its period of retention (30,60, or 90 days). When the job
NONPERMANENT LABELS.— The nonpermanent type label has a special adhesive backing of
stick-on-type construction that can be applied to just
about any kind of surface yet be removed with very little
effort. This type of label is most useful in applications
where information regarding the media itself, or what is
written upon it, changes quite frequently. Usage labels,
cleaning labels, and save labels are usually
nonpermanent type labels.
Usage Label. — The usage label is used to
determine how many times a tape has been read from or
written to. It can be placed on either side of the tape reel.
The usage label is normally made up of several boxes or
circles (approximately one-quarter inch in diameter),
which are filled in (one at a time) by the computer
operator each time a tape is used. Notice that we did not
mention disks. Disks are normally sent outside of the
command for cleaning. At that time, they are also
certified for use. However, magnetic tape is an entirely
different story. After so many uses a tape must undergo
Figure 2-6.—Magnetic tape save label for unclassified
(UNCLAS), Privacy Act (PRIV), and For Official Use Only
Initialization is somewhat similar to an initiation. If
the disk pack (or diskette) passes a series of tests, then it
gets to become a member of the library. If not, then the
media is normally boxed up and shipped back to the
manufacturer. To initialize a disk pack, you must have
computer processing time at your disposal and a special
program called a direct access storage device
initialization (DASDI) program. The initialization
procedure itself is designed to accomplish two things.
First, during the DASDI procedure, an internal volume
identification is recorded on track zero of the disk.
Without this volume identification label, the computer
cannot access the disk. Second, for a new pack, a
surface analysis of the entire disk (or disk pack) is
performed, defective tracks are flagged, and alternate
tracks are assigned. In addition, a listing is produced
that reflects the overall operating condition of the pack.
This listing is normally retained in the library or in the
technical support branch.
is run, the operator inserts the remaining entries: reel
sequence number(s), the creation date of the file, the
system on which the job was run, the magnetic tape unit
(the drive #) that was used to create the tape, along with
his or her operator number or initials upon completion
of the job. These newly created tapes are then
forwarded to the library, where you (the librarian) check
to see that all required entries on the save label have
been made. If there are discrepancies, it is your
responsibility to notify the appropriate personnel so that
corrective action may be taken. Once you are satisfied
that all label entries are correct and complete, you can
then proceed to log and file (store) the media for future
Whenever you are asked to pull (retrieve) magnetic
media (input tapes, disks, diskettes), you should ensure
that save labels accompany the job request for all
outputs to be saved. Do this before releasing the job to
the computer operator.
As you travel from one command to another, you
will find that there are many DASDI programs
available, under just as many names: INIT, FORMAT,
and so on. The one you use will depend upon the
system’s hardware and its executive software.
Internal Labels
Before releasing new magnetic media from the
library, you are sometimes required to put the media
through what is called an internal labeling or
initialization process. As the librarian, one of your
many jobs may be to perform this labeling or
initialization process. Why? you might ask. Good
question. Some computer systems require an internal
label of some sort to be physically written on the
magnetic media for validation (checking) purposes
before the media can be accepted and processed by the
system software and applications programs of the
Have you ever given any thought to how much time
and money are invested in the library? If you are not
working in the library at the moment, next time you visit
one, look around and try to imagine how much money it
would take to replace the equipment and the media, and
how much time it would take to recreate all the
necessary files if everything were totally lost because of
fire or flooding. Depending on the size of the library
and the types of media it contained, it could run into the
millions of dollars. Remember, data entry personnel do
not work for nothing. The loss of these media can have
harmful effects on your command’s operations for quite
some time. And, as we have already noted, recreation of
files can be extremely costly.
When dealing with magnetic tape, the internal label
consists of two blocks of information written
immediately after the BOT marker. The first block is
normally reserved for the identification number, which
is assigned by you at the time a new tape is added to the
library. This identification number never changes. The
second block identifies the information to be stored on
the tape, along with the file ID. It may also contain date
information that is used by special programs to further
identify the tape and to protect the information from
being destroyed prematurely. This type of information
is normally provided by the programmer. You must
schedule computer processing time to set up the internal
All systems software, master files, and other critical
entries and documentation should be duplicated as
backup on a regularly scheduled basis and stored in a
protected area, as far away from the library as possible.
In spite of the many precautions that can be taken to
protect the security of the computer center and the
media library, the safest possible means of protecting
data and information of a vital nature is the off-site,
back-up procedure. This is true because there is no
totally fail-safe procedure to protect a computer room or
the library from the many dangers to which it is
Like magnetic tape, whenever you introduce anew
disk or diskette into the system, it, too, must undergo an
internal labeling process known as initialization.
It is up to the individual programming branch
supervisors, operations supervisor, or division chief to
ensure that all projects, systems, or jobs under their
cognizance or control be identified, duplicated, and stored
off-site in accordance with local Continuity of Operations
(COOP) instructions.
Off-site magnetic media should be changed each time
the data/information is updated. In the case where daily
updates occur, backup files should be minimized to once a
week if at all possible.
As librarian, you should have an established standard
operating procedure (SOP) to copy master files for the
various types of media, for use in the event the originals
become damaged. Copies should be made each time a
master file is updated. These copies can be the actual
COOP tapes/disks or duplicates, depending on the
proximity of the COOP storage site and the delay in
operations required to retrieve the copies. If the COOP site
is distant from the operation, the COOP files should be
duplicated and the duplicates stored within the library for
fast recovery.
Figure 2-7.—Magnetic tape in a canister.
handle a tape the possibility of damage increases, especially
to the outer edges of the tape. Devices, such as canisters
and wrap-around (tape) straps, help protect the reel and tape
during handling and storage. The canister tape seal shown
in figure 2-7 offers the maximum protection against dust
and physical abuse. Canisters provide a dust-free
environment and support the tape reel by its hub. Canister
tape seals are normally supplied by the manufacturer,
unless your command specifically asks for another type
such as the wrap-around strap.
Occasionally, you will be expected to ship media to
another site. The most important thing to remember to do
before packaging a tape or disk up for shipment is to make
a copy. There is nothing worse than mailing off a disk or
tape and the recipient finding it blank when it arrives, and
you don’t have another copy.
Some AIS installations prefer to use wraparound
straps, better known as tape straps, instead of canisters
because they are far less expensive and take up less
storage space in the library, figure 2-8. Unfortunately,
tape straps do not provide the same degree of protection
from dust or physical abuse as do the canisters. It is
The following steps should be followed to prepare
media for shipment:
Pull media from the library
Copy the media, returning original to library
Box media in shipping container
Label container
Affix warning labels on all sides
The warning labels should state that the package contains
magnetic media; do not xray.
While it is inevitable that computer tape eventually
acquires errors, you can help minimize tape errors through
proper handling techniques. Tapes should never be
handled unnecessarily, because each time you
Figure 2-8.—Magnetic tape in a wrap-around (tape)
possible for a person to squeeze the reel flanges during
handling even though a tape strap is properly in place, as
shown in figure 2-9. Handling tapes in this manner will
certainly result in tape-edge damage. In addition,
defective or improper size straps may deflect (twist or
warp) the reel flanges, causing tape-edge damage.
Nonetheless, when handled with care, the wrap-around
tape strap can bean effective method of tape protection.
While working with tapes in canisters, canisters may
be stacked for short periods of time.
NOTE: Avoid stacking more than 10 canisters,
since weight can cause the canisters on the bottom
to crack.
Anytime you are handling magnetic tape,
regardless of how it is protected (by a canister or a tape
strap), always use good judgment and follow the
applicable safeguards, as follows:
Never use rubber stoppers with wrap-around straps.
The extra thickness could result in the tape being
embossed (leaving a permanent imprint).
When a tape is not actually being used, keep it
in its protective container to avoid accidental
breakage and unnecessary contamination.
Do NOT leave empty tape canisters open as
this allows entry of dust or other tape
contaminating matter.
Avoid stacking tapes with wrap-around tape straps,
because doing so can cause tape-edge damage.
Store magnetic tapes in a vertical position.
Always handle tape reels by the center hub, never
by the flanges.
NOTE: If you happen to drop a tape reel, check it
immediately for cracked flanges and the tape itself
for possible edge damage.
Hang wrap-around straps in a clean area while
the tape is in use.
Whenever you return a tape to its respective
canister, you must ensure that a clean stopper is
NOTE: A stopper is a one-inch piece of foam
rubber the same width as the reel (inside the
flanges) and one-half-inch thick. Stoppers are
used to keep the tape from unraveling once
inside the canister.
Figure 2-9.—Magnetic tape being held improperlythe fingers should go through the hub hole without
squeezing the flanges.
Periodically remove and check inside the flange and
hub areas of take-up reels on tape cleaning and
certifying equipment for dirt or other contamination.
Also check these reels (at the hub) periodically for
signs of warpage or cracks. Periodically check the
mounting hubs on your equipment to ensure they are
tight (secure). This prevents a reel of tape from
wobbling during a cleaning or certifying operation.
When you mount a tape on a device, always push in
on the hub itself, never on the outer flanges.
Never touch or handle the recording surface of the
Never place magnetic tape on top of equipment
because of the heat generated by the equipment and
because internal magnetic fields within the device
may scramble recorded bits of information on the
Smoking should not be allowed in working spaces
where magnetic tape is being used. Smoking is
never permitted while handling magnetic tape,
attending to tape units, or working in the library
area. Ashes may contaminate tapes, and live ashes
may cause permanent damage if they come in
contact with the tape.
and storage cabinets on a regular basis (at least once a
week) to prevent dust buildup.
And last, but not least, always follow the rules
and procedures that have been established by
your command or installation. Check your SOP
It also means you must examine disk pack filters as
often as possible (preferably after every use) to ensure
there is no dust buildup or damage of any kind. If dust
buildup or damage to the filter exists, by all means,
replace the filter before it is to be used again. Be sure no
foreign objects or notes are placed inside the disk pack
covers. Foreign objects have a tendency to fly and, as a
result, could slip between the disk platters and become
undetectable until the disk pack is used. This would
certainly cause severe damage to the pack and drive and
make your maintenance technician very unhappy. If, for
any reason, you suspect a disk pack has been damaged
or dropped, under no circumstances should you release
it from the library until it is checked out by a person
using an authorized pack cleaner/certification device.
Remember, anytime your library personnel are to
handle magnetic media, whether it be issuing, receiving,
filing, scratching, inventorying, or mailing, they need to
be on the lookout for certain things. They must look for
such things as tapes that are unevenly rewound, write
rings that have not been removed from a newly created
file, cracked tape flanges, worn tape straps, broken or
cracked tape canisters, faded or peeling file
identification or reel identification labels, mismatched
tape reel number against tape strap number, and soon.
Media with problems such as these should not be
released for use or filed in the library until the problems
are corrected.
Anytime you are retrieving, storing, or just plain
handling a disk pack, always carry it by the handle
located on top of the cover, as illustrated in figure 2-10.
The handle is designed in such a manner that the pack is
supported at its center by locking the cover to the
spindle on the pack. You must ensure that the bottom
cover of the pack is firmly secured (attached), while
holding the pack vertically by the handle. You should
never set the pack down onto the bottom cover. The
locking knob, which is cone-shaped, could puncture the
pack’s filter or possibly bend the disk’s lower platter.
As the librarian, you are primarily concerned with
the care, handling, retrieving, storing, and labeling of
magnetic media. When we care for magnetic media
(especially disks or diskettes), an important element of
that care is cleanliness. Disk packs, as well as diskettes,
have a tendency to attract dust, smoke, oil, hair, you
name it, and a disk pack will attract it (or at least it
seems that way).
Because even tiny particles can cause problems, it
is imperative that all AIS spaces (including the media
library) be as contamination-free as possible. For you,
that means all disk pack file drawers must be kept
closed when not in use. Vacuum the disk pack covers
Figure 2-10.—Magnetic disk should be carried level,
using the dust cover handle.
cases, the reduced length will not detract from its
How important is tape cleaning and recertification?
Let us answer that question by asking another question:
When do you suppose tape failures are most likely to
occur? If you answered, when the tape is being used on
the computer system; then you are correct. Consider this
example: an unrecoverable tape error appears while the
operator is trying to read in reel four of an eight-reel
master file; the operator is about 3 hours into a very
important job, and finds out there is no way to recover
(restart) the job starting with reel three of the input. A
failure at this stage of the operation gets the operator
and a good many other people very upset, for we all
know that reruns are costly in both time and money.
Such failures can be avoided if tapes are cleaned and
recertified on a regular basis. It is well worth the effort
to properly care for tapes according to a regular planned
schedule; since this avoids upset and inconvenience and
gives your users confidence that your AIS facility is
running smoothly.
This procedure is known as stripping a tape. After a
tape has been stripped five times, it should be reloaded
(transferred) onto what we call a mini-reel. A mini-reel
is about half the size of a standard reel of tape.
If the errors continue throughout the length of the
tape, you should determine whether the errors are
distortion errors or dirt errors. Distortion errors are
usually the result of careless handling (abuse) of the
tape and can rarely be corrected. Distortion errors can be
seen as wrinkles, creases, turned-up edges, or a slight
stretching of the tape. Dirt errors usually result from the
accumulation of microscopic foreign matter on the tape
surface and can be removed by careful cleaning. To do
this, you need to use a tape cleaner.
Tape cleaning is the process of removing all
foreign particles (known as residual buildup) and
protruding debris from the oxide and back side (the
shiny side) of the tape. This process does not destroy
any of the data that has been previously recorded on the
Careful and planned maintenance of magnetic tapes
can minimize and even possibly eliminate a lot of lost
computer time. The first step in every magnetic tape
maintenance program is, obviously, careful cleaning.
Despite the many safeguards against contamination, you
can believe that magnetic tape will eventually acquire
some contamination and cause read or write errors.
New tape has a tendency to shed oxide particles
near the surface for approximately the first six passes
through the read/write heads of the magnetic tape unit.
Unless the new tape is cleaned at least twice, increased
tape unit head wear could result. You will also find that
deterioration of the edges of the tape is the major cause
of most tape-generated debris. Edge guides that help to
direct the tape along the tape path also cause a constant
edge-scuffing. This results in a further breakdown of the
oxide/base layer interface of the tape. An effective
You will find the greatest number of tape errors
normally occur in the first 100 feet of a reel. When this
is the case, the appropriate action is to cut off the
contaminated area, relocate the BOT reflective marker,
and continue to use the tape (see figure 2-11). In most
Figure 2-11.—A 100 feet of contaminated tape being removed from reel (stripping).
process to clean a tape is to use a magnetic tape
cleaner/certifier similar to the one shown in figure 2-12.
chart (figure 2-12, upper left-hand corner). The location
of each error is identified by its distance from the
beginning-of-tape (BOT) reflector. On the second pass,
that is the return pass, the certifier stops at every
unremoved error area and the operator, using a
microscope, endeavors to remove the error with a sharp
knife or scalpel. Upon completion, a recertification
operation will usually restore the tape to a near errorfree condition. On a 2,400-foot tape reel, each
recertification operation averages 15 minutes.
Knives are used to remove any protrusions from the
oxide surface. It is estimated that a maximum of 90% of
all tape errors are removed in this manner.
Most tape cleaners clean tape by wiping the oxide
and back surface of the tape. Loosened dirt, oxide
particles, and other debris are removed from the tape by
wiping assemblies. When the EOT marker is sensed by
a photoelectric cell, the tape is automatically reversed,
and the wiping assemblies clean the entire length of tape
in the opposite direction. The wiping tissue used is made
of a special textured fabric and is wound on a spool.
All tapes—scratch tapes, work tapes, save tapes,
and data tapes—should be cleaned after every 10 uses or
every 90 days, whichever is more frequent. All tapes
should have a cleaning label attached to the back surface
of the tape reel. Each time a tape is cleaned, you should
log the Julian date and initial the cleaning label.
It is important to change the wiping material
frequently at the point of contact with the tape. This is
done to avoid entrapment and retention of abrasive dirt
particles at the tape surface being wiped. Some tape
cleaners, like the one shown in figure 2-12, move the
wiping material along automatically.
Some helpful measurement criteria, used by several
of the AIS installations for determining retention or
disposal of magnetic tape, areas follows:
ABSOLUTE-END-OF-LIFE— The tape contains so
many flaws (errors) that it can not function at all.
In addition, most tape cleaners repack the tape as it
rewinds, using a built-in machine programmed tension
arm. This feature helps to relieve irregular tape pack
tension, thereby reducing the possibility of tape
deformation inside the tape reel. The repack tension arm
is shown in figure 2-12.
produce usable results, but because of cost and
annoyance of failures, it is impractical to use it any
Tape cleaning equipment that combines tape
cleaning and recertification (figure 2-12) operates in the
following manner. Any protrusions are removed by a
knife edge during the first tape cleaning pass. At the
same time, the location of every error that was not
removed on the tape pass is indicated on a recording
LEVEL-OF-REJECTION— This is a judgment call
and must be based on your past experience or expertise,
you might say. Some librarians and management
personnel feel that after a tape is cleaned, if 15 write
errors occur throughout the tape, then the tape has
reached the threshold of rejection.
Figure 2-12.—Tape cleaner/certifier.
Ensure that proper and regular operator
maintenance is performed on the library’s equipment.
Keeping a log of when it was conducted and when it
should be done again will help. Make sure outer
cabinets are kept clean and free of dust. All dirt, oxide
particles, and other debris should be removed from the
capstans, turrets, tape pack wheel, and cleaning blades.
Cleaning blades should not be allowed to become
nicked or dull. Also see that the wiping tissues are clean,
and are rotating smoothly and automatically.
at which the number of errors exceeds the rejection
Maintaining Magnetic Media
Maintaining media involves using specialized
library equipment to clean, certify, and degauss
magnetic media. It also involves seeing that media is in
usable condition. The duties and responsibilities
include the following:
Splicing leaders onto magnetic tapes
Placing BOT/EOT markers on magnetic tape
Today, the removable and interchangeable
magnetic disk pack is one of the most frequently used
mass storage media. Not only is it small, fast, and
reliable, but with the proper care and handling, it has an
almost indefinite life span. Like magnetic tape, the
main enemy of the disk pack is dirt. During the
manufacturing of the disk packs, every precaution is
taken to maintain a sterile environment and a
contamination-free assembly of each component of the
disk. However, these safeguards do not entirely prevent
some contamination from occurring, and everyday
operation continues to increase the contamination level
until data checks (read/write errors) do occur.
Rotating tapes and disks
Inspecting and changing disk pack filters
Setting up and operating tape cleaners, certifiers,
and degaussers
Mounting and dismounting magnetic tapes
Performing cleaning, certifying, and degaussing
Performing emergency shut-down/power-off
procedures on equipment
During normal computer use, three different types
of errors are encountered on disk packs: temporary
errors, permanent errors, and disastrous errors (head to
disk contact or head crash).
Setting Up, Operating, and Maintaining
Be sure you and the head librarian know and can
explain the steps involved in setting up and operating
equipment. Be able to demonstrate the proper way to
clean, certify, and degauss magnetic media. Be sure all
library personnel know how to properly perform
emergency shut-down/power-off procedures on the
different types of equipment used in the library (tape
cleaner, certifier, degausser, and remote computer
terminal, if used).
CHECKS— These temporary errors are the direct result
of a minor buildup of contaminants, such as dust,
smoke, and oil.
CHECKS— These permanent errors cause data to be
lost because of an excessive buildup of contaminants.
As a result, the read/write heads are no longer able to
access this particular area on the disk.
Like any area with equipment, some operator
maintenance is required to assure proper functioning
and also to increase the useful life of the equipment.
Operator maintenance on tape cleaners and certifiers
should be performed on a regular basis and include the
following tasks:
CRASH— These disastrous errors are caused when a
read/write head of the disk drive unit comes into direct
contact with the surface of a disk platter. Again, this is
the result of an excessive buildup of contaminants.
. Removing and replacing cleaning blades
These errors can be prevented by inspecting and
cleaning the disk pack. Although none of the major disk
pack manufacturers recommend a regular schedule for
cleaning of disk packs, they do recommend that disks be
cleaned and inspected when they have been exposed to
. Removing and replacing wiping tissues
. Removing dirt/dust from photoelectric cells
. Ensuring tape pack wheel is rotating freely
minutes per reel for a magnetic tape with a maximum
one-inch width.
possible moisture or contamination. The fact is, during
operation, the disk pack is surrounded by dirt and grease
particles that are circulated through the air by the
cooling fans of the disk drive; consequently, there is a
definite need for a cleaning procedure, if not an actual
schedule. If your installation has a disk
cleaner/certifier, learn how to use it, and you will find
fewer disk errors and a significant decrease in the
number of computer reruns. A well-organized disk
management program will serve to eliminate head
crashes caused by contaminants; decrease, if not
eliminate, hard data checks; and decrease significantly
the number of soft data checks encountered.
Magnetic Disk, Diskette, and Drum
Rigid magnetic media such as disk and drum
storage, as well as diskettes (also known as floppy disk),
should be machine cleared (overwritten), using a
specially designed computer software program. Once
the media has been overwritten, it should be verified
(checked) to be sure the read mechanism cannot detect
any traces of data information except the characters
used in the overwrite procedure. Only then can the
media be considered as unclassified, and all
classification labels and markings identifying the
subject matter be removed. You should also ensure the
computer operator checks out the computer and all
related components that are to be used immediately
before beginning the overwrite procedure. This is to let
you know that malfunctions, which could prevent the
classified information from being effectively
overwritten, do not occur. During the overwriting
process, all storage locations will be overwritten a
minimum of three times, once with the binary digit “1 ,”
once with the binary digit “0,” and once with a single
numeric, alphabetic, or special character (other than “0”
or “1”). The current used in overwriting must be equal
to that used when the data was first recorded, but not so
strong that it will damage or impair the equipment. If
the storage device fails in such a reamer that it cannot
erase the data from the media, the media may be
declassified by exposing the recording surface(s) to a
permanent magnet having a field strength at the
recording surface of at least 1500 oersted. Care must be
taken to ensure that the entire surface is wiped at least
three times by a nonuniform motion of the magnet.
Care must also be taken to assure that all tracks are
covered by the center of the magnet. A thin sheet of
clear plastic (a 1-to-5-mill sheet) should be used to
prevent any damage to the recording surfaces.
Degaussing magnetic media—tapes, disks, and
drums-involves a process in which you demagnetize
the media itself. This rearranges all the 0 and 1 bits, sort
of mixing them up, you might say. Normally, the only
time you would be required to perform such an
operation is when you must declassify (remove the data
from) the media before the media can be scratched for
reuse. To remove a previously recorded magnetic signal
(all the 0 and 1 bits), use a concentrated magnetic field
to magnetically saturate the oxide coating of the media
and randomly orient all the magnetic particles.
Magnetic Tape Degaussing
To degauss a magnetic tape, you must pass the
entire tape through controlled fields of alternating
current to reduce the signal level of the magnetic tape’s
recordings to a level which is below the capability of
ADP equipment to interpret. This requires that signal
level reduction be performed on the entire reel of
magnetic tape, including the tape leader and tape trailer.
For a tape 1 inch or less in width to be considered
unclassified by the National Security Agency (NSA)
standards, the signal on the tape must be reduced a
minimum of 90 dB (decibels) below saturation level
after degaussing. The manufacturer’s recommended
operating procedures should be followed when
degaussing a tape. Also, the tape degausser should be
checked at least quarterly by technical personnel to
ensure proper operating level specifications.
When it comes to the destruction of magnetic tape
and diskettes, you will use the same techniques as hard
copy material. Depending to the equipment available to
you, you will shred or burn the material, depending on
the classification and the type of equipment. Because of
their design, some of the shredders can not be used to
shred magnetic tape or diskettes. Remember to use your
local standard operating procedures (SOPs) as guidance
Before degaussing a tape, you should remove the
tape wrap-around strap to prevent the reel from
jamming, and secure the end of the tape with a foam
rubber stopper to prevent the tape from unwinding. The
degaussing operation itself takes no more than 2
for the destruction techniques that are used at your
MAGNETIC DISK— Look for contaminants inside
and outside of the disk pack covers, cracked or broken
covers (top and bottom), and damaged or warped disk
platters. Be sure the locking mechanism is functioning
contaminants, primarily dust and oily marks on the
outside cover.
As librarian, one of your many tasks may be to
release (scratch) magnetic media; that is, make the
media available to the computer operator for reuse.
Before you release or scratch media, there are several
things you should know. First, never remove a save
label from a tape, disk, or diskette without the
permission of the user to whom the data on the media
belongs. Well, then you might ask, how does one go
about getting the user’s permission? There are several
ways this can be accomplished: by phone, by way of an
interoffice memo, or by contacting each individual in
person; but the fastest and easiest way is to distribute a
copy of the release report on a weekly basis. The users
can annotate the files they want released and return the
report to you. At that time, you can scratch the
appropriate files and make the magnetic media
available for reuse.
Finally, be sure to place (insert) a write ring in the
slot provided on the back side of each scratch tape.
Forward the magnetic media to the computer operations
area. Do not forget to follow up on the paperwork. That
is, update the library master file (or database) to reflect
latest status on the media.
But wait, is the file you are about to scratch the same
file that is listed on the release report? Good question.
Before you start removing save labels, be sure that all
information written on the save label agrees with what is
listed on the release report. There are times when the
computer operator is in a hurry to get things rolling and
may accidentally place the wrong wrap-around strap on
a tape, disk pack cover on the wrong disk, or attach the
wrong save label to a newly created file. By performing
this check, you could avoid hours of computer rerun
time. Once you have determined the file to be scratched
agrees with the information on the release report, you
can remove the save label.
Next, you should look at the usage and certification
labels to see whether or not the tape or disk needs to be
cleaned or recertified; and if so, do it.
In addition to performing library functions, you will
need to consider other areas of library management.
These include protection and storage of media,
maintaining a proper physical environment,
management of classified media and materials,
magnetic media administrative duties, tape retention,
and disaster/off-site backup. You will learn about these
management areas in this topic.
Data is one of your installation’s most valuable
assets, and, as the librarian, you are responsible and
accountable for its protection. You must protect it from
a number of things. The data that is recorded on
magnetic media must be protected from theft,
unauthorized access by individuals, destruction by fire,
flooding, contamination, accidental overwrite, and so
on. The key words here are protection and security, not
only of the media but also of the library spaces as well.
If the file to be scratched contains classified data, be
sure the media is degaussed before its release unless it is
to be used again for the recording of classified data of
the same security level.
The library must be theftproof. It should be of
vault-type construction, with no windows and with
cypher locks (or their equivalent) on the doors.
Personnel access must be closely controlled. You must
follow proper procedures to ensure that material
entering or leaving the library is controlled. You should
be aware of the fact that security means more than the
loss of data through theft or sabotage. If the user cannot
depend on the data, as recorded. on magnetic media and
retrieved from the library, then the entire library
becomes worthless. Regardless of the classification of
Next, examine the media thoroughly to be sure it is
healthy (in good physical condition). Be on the lookout
for the following problems:
MAGNETIC TAPE— Look for contaminants on
inside and outside of flanges, tape unevenly rewound
(take note of the tape unit it was created on), cracked or
warped flanges, cracks around the center hub (if made
of plastic), uneven tape packing (look for ripples
between the layers of tape), and broken or deteriorated
locking mechanisms.
the data your command processes (Unclassified,
Confidential, Secret, Top Secret), you must ensure that
the library is secure.
Another security requirement is fire control. Smoke
and fire alarm systems are necessary. Sprinkler systems
that react immediately to any threat of fire area must.
Insulated vaults (safes) and storage cabinets like the
ones shown in figure 2-13 are extremely helpful in
preventing magnetic media and paper records from
being destroyed in the early moments of a fire before it
can be put out. They can also help reduce the heat to
which the storage media are exposed. Heat can be
particularly harmful and damage the data even if the
medium itself is not destroyed, because plastic melts,
and metal warps.
Figure 2-14.—A lead strip bolted in the vault
door hinge.
If the storage devices are insulated, this will further
protect against water damage, either from natural
accidents, such as floods, the sprinkler system, or
personnel putting out a fire. Some commands prefer to
use an inert-gas extinguishing system, or chemical fire
extinguishers rather than the conventional water
sprinklers. These help to eliminate the damage and
contamination that would otherwise be caused by water.
Another safety feature is the lead-strip vault door hinge.
The lead strip will melt at 150°F and automatically close
the vault door (see figure 2-14).
computer facility. If not, the media should be placed in
the proper environment for a minimum of 24 hours
before using; otherwise, the operators may encounter
problems using the media. Temperature and relative
humidity tolerances should be maintained within
specified limits. In the absence of other instructions,
maintaining a 30 to 60 percent relative humidity at 70°F
to 80°F is considered an acceptable environment.
In the library, especially the tape cleaning area, the
elimination of dust, lint, and foreign matter on
equipment is necessary for efficient operation. In short,
the cleanliness of equipment, floors, and contact areas
and the control of humidity and temperature are
The library is usually located in the same
functional area as the computer room it is supporting.
This is especially true aboard ship. Magnetic tape,
disk, and other media must be maintained within the
same environment, or the same type environment, as the
Traffic in and out of the library should be kept to a
minimum. Smoking, eating, and drinking should be
prohibited at all times.
The library should be vacuumed and/or cleaned
with a damp mop. A dry mop, fox tail, or dust broom
should never be used, as they tend to kick up more dust
than they take up. Aerosols should never be used in the
library environment, because the oily, dust-collecting
moisture settles and eventually finds its way onto the
equipment as well as the surfaces of the media.
The use of air-conditioning filters in the library
should be given special attention, because fiber glass
filters often fail to prevent the penetration of fine silts
and tend to deposit particles of fiberglass on magnetic
Figure 2-13.—Media storage vault and cabinet
(with doors open).
materials, how do I go about keeping everything
uncomplicated and on track? The answer is simple:
follow established command procedures, know where
the materials are located, and keep track of classified
media and materials at all times, whether they are in or
out of the library. The keyword here is accountability.
As the media librarian, you must ensure that all
classified magnetic media bear some type of external
markings or labels and internal notations. The markings
must be sufficient to assure that any one receiving such
media will know that classified information is involved
and what its specific classification category is.
Every reel of magnetic tape, disk pack, and diskette
that are to be used for recording classified information
should have a stick-on, pressure sensitive classification
label, specifying the classification of the highest level of
information ever recorded on this media. (See figure
2-15.) In addition, after recording has taken place, you
must ensure that the proper save label has been placed
on the face (front) side surface of the media. This label
should contain the highest classification of information
recorded on the media, the date the recording was
performed, and other appropriate identification
information required by your installation. Magnetic
media that is not the property of your AIS installation,
but which is on loan from another installation, (known
as foreign tapes, disks, and so on), should be isolated in
the library and separated according to security
classification. Classified magnetic media received from
other AIS installations should be degaussed before you
return it, unless the sending organization specifically
requests the media not be degaussed.
The unique methods employed when handling,
processing, storing, degaussing, transferring, or
mailing this type of media require correspondingly
unique security procedures, some of which you read
about in Module 1, “Administration and Security.”
Additional information regarding these and other areas
related to AIS security may be found in OPNAVINST
5239.1, Automatic Data Processing Security Program,
and OPNAVINST 5510.1, Information and Personnel
Security Program Regulations.
The rules, regulations, and procedures in the
OPNAV instructions and local command instructions
are there for good reason. They provide you with the
information needed to protect classified materials and
media, and their contents. It is up to you to carry out
these procedures, without unduly complicating AIS
Before returning the degaussed media to its rightful
owner, a certificate of destruction should be filled out
and retained in the library. For reasons of security,
You are probably asking yourself, as a librarian
charged with the responsibility of handling classified
Figure 2-15.—Classification labels.
copies of the certificate of degaussing destruction
should not accompany the media during transmittal.
l Labeling magnetic media
l Establishing and updating current and history
Performing Security Functions
l Preparing library listings and reports for
Security functions are very important in a magnetic
media library, not only for classified media but also for
any material. Data has value, whatever its classification
or use: Top Secret, Secret, Confidential, Privacy Act,
For Official Use Only, or Unclassified. Applicable
security instructions and procedures must be followed.
Some of the tasks include the following:
l Storing and safeguarding classified media and
l Maintaining security logs and library access lists
l Degaussing and/or destroying classified media
and materials
l Changing lock combinations on doors, safes, and
Ensure that all security procedures and measures
relating to the library are understood by everyone
connected with the library, especially the librarians.
See that procedures are enforced. This includes
controlling entrance (access) to the library spaces (both
on-site and off-site storage areas), as well as providing
physical and administrative controls of the media. The
librarians must ensure proper security protection is
provided for all magnetic media and materials in
accordance with applicable security instructions and
procedures. This includes issuing, receiving, shipping,
declassification, destruction, and disposal.
To accomplish this task requires a specially
designed program that is able to read the internal label
information that is stored on the magnetic media. The
program extracts whatever information it needs to build
a record onto the library master file (or database file).
Once a record is established, you can make changes or
deletions as necessary.
Most AIS installations have incorporated or are
capable of installing some type of automated tape
library control (ATLC) program. Various
manufacturers supply these software programs for their
computing systems. These programs provide an
automated capability for preparing various user and
management reports to assist in the operation and
control of your installation’s magnetic media library.
These reports reflect the current status of each tape reel,
disk pack, and diskette in the library. You will find that
various manufacturers give different names to their
library accounting programs; however, the majority of
these software systems accomplish the same functions.
The names may change, but the game is the same. For
this chapter, we use ATLC.
Attention to administrative detail is a must. It will
help assure that media are properly maintained and
ready for use. Control logs, pass-down log, library
listings, and reports are all a part of the everyday
administrative functions. Administrative duties and
responsibilities include the following:
. Maintaining tape cleaning, verification, and
degaussing logs
A good ATLC system should be capable of
providing you with the library edit and error, reel master
list, application, user/programmer, media to be
released, library maintenance, off-site storage, and
history reports.
l Checking magnetic media in and out, using
appropriate logs
l Making entries in tape and disk control logs
l Making entries in pass-down log
The main purpose of any ATLC system is to relieve
you of having to maintain numerous logs and library
files by hand. So, if your AIS installation has an
automated library control system, take full advantage of
it; otherwise, you can look forward to many, many hours
of manual labor. You will also find that the number of
tape and disk accountability problems will be lessened
considerably under an automated system.
report provides you with information and error-type
messages pertaining to the ATLC system transactions;
those submitted, rejected, and processed.
MASTER LIST REPORT— This report provides
you with information pertaining to each type of media
contained in the ATLC system. This report is normally
listed in identification number sequence.
Using Remote Terminals
APPLICATION REPORT— This report provides
you with information pertaining to media assigned to
any particular project (supply, payroll, and soon). This
report is normally listed by project number and
identification number.
Many tape libraries use remote terminals connected
to mainframes or minicomputers to help manage their
library functions. The automated library control system
(ALCS) is one use. Remote terminal operation will
include the following tasks:
provides you with information pertaining to media that
is assigned to a particular user or programmer. It should
be in user/programmer number, release date, and
identification number sequence.
Performing log-on/log-off procedures
Entering proper system passwords to assure
Inputting data to computer
provides you with information pertaining to the media
that are scheduled to be released (scratched according to
purge date). It is normally listed in identification
number and/or in file-ID sequence.
Retrieving data from computer
Updating library files using ALCS
Querying/searching library files using ALCS
provides you with information regarding the media
itself, indicating when the media was last cleaned, when
it was last stripped (magnetic tape only), and recertified.
This report is normally listed by media type (tape or
disk) and identification number.
Requesting library listings and reports
provides you with information pertaining to the media
that are stored off-site. This report is normally listed by
media type, release date, and identification number.
HISTORY REPORT— This report provides you
with various information pertaining to all magnetic
media classified as history files. This report should be
listed in media type, release date, and identification
number sequence.
Ensure that all library personnel are properly
trained on how to use the library’s remote computer
terminal. All personnel must have a good working
knowledge of the features and functions of the
keyboard. They must know how to properly logon to
the system and how to enter their access code. They
must also understand how to gain access to library files
and how to input and retrieve data to and from the
computer. They should know how to update and query
the library’s database and how to request library listings
and reports. Knowing how to close out files they are
All input, changes, and deletions to the ATLC
systems database (master file) should be accomplished
by the librarian to ensure database integrity. You should
have up-to-date information on how to properly
maintain the ATLC system so you can key-enter (via
CRT) new records, make changes to existing records, or
delete records entirely. You must also know how to use
input parameters and possibly SCL parameters to
produce the appropriate output products.
part, called the file name extension, is optional, and can
be from one to three characters. While the extension is
optional, the primary part of the file name is NOT. An
extension cannot name a file, it can only be used to
further qualify or describe a file. If both parts are used,
they must be separated by a period, for example,
TELECOMM.TP7. To name a file (including its
extension), you may use any combination of the
following characters: the letters A through Z (upper and
lower case), the numbers 0 through 9, the following
special characters: $, #, !, %, ( ), -, { }, _, and the left and
right apostrophe.
working with, and how to properly logoff the system at
the end of their work day are also important parts of
their job.
A restricted retention period has been established to
prevent permanent physical damage to magnetic tapes,
especially tapes that are stored for long periods of time,
such as history tapes. This provides for all magnetic
tapes to be cleaned, possibly certified, and repacked at
prescribed time intervals. This procedure eliminates
such problems as oxide sticking, debris embedment,
and edge deformation caused by tape pack shifts inside
the reel.
Why would you want to use an extension? you
might ask. Let’s assume you created a file that contains
all E-4 evaluations for the year 1997 and you named the
file DIV-EVAL. It’s a perfectly good and valid name
under DOS. However, it is entirely possible you would
want more than one file called DIV-EVAL, considering
the years that follow. In this case, you might want to use
the option of adding a file name extension. For
example, you could label the 1997 evals DIV-EVAL.97,
the next year’s DIV-EVAL.98, the following year’s DIVEVAL.99, and so on. In this case, the years 97,98, and
99 are the extensions.
Initially, an on-site save tape retention period
should be restricted to a maximum of 90 days, with only
one 90-day extension. After 180 days, you should
notify the user indicating that the tape should be copied
(and verified) onto a recently cleaned tape, thus freeing
the original tape to be tested for accuracy. The retention
period for off-site tapes should initially be 180 days,
with one 30-day extension.
Some extensions have special meanings in DOS
and are either created by DOS or assume the file
contains a special type of program or data. For this
reason, use extreme caution and avoid using file
extensions defined by the program or operating system
you are using. Examples of extensions assigned by
DOS are as follows:
File and disk management are other areas where
your knowledge will help users. They probably don’t
know the agony of delete or the problems sometimes
caused by very large files. Think about what you have
learned regarding file management. How to name files.
How to cleanup files. How to back up files. When to
back up files. Where and how to physically store files.
How to protect files. How to organize files on disks.
Let’s examine some of the considerations for setting up
files and file management procedures for
microcomputers: naming files, disk file organization,
and file backup. We will be using DOS as the operating
system for the examples in this section.
COM, EXE, SYS, BAT— File extensions such as
COM(mand), Executable), SYS(tem), and BAT(ch)
contain executable code. That is, the code is actually
understood by the hardware when programs are run.
BAK— When opening a text file, the DOS program
automatically makes a backup copy with the
extension BAK.
Naming Files
BAS— BAS refers to a source program written in
the BASIC language.
Every newly created file must be given a file name
if it is to be stored (written and given an address) on
disk. When the operating system looks for a filename,
it looks up the address in its “address book,” the
directory. The directory is maintained in a fixed
location on every disk.
COB— COB refers to a source program written in
HEX— HEX refers to a special type file where all
information has been stored in HEXADECIMAL
Every operating system will have a system for
naming files. In DOS, file names have two parts. The
first part, the primary file name, names the file and can
be from one to eight characters in length. The second
Various applications software packages
automatically add an extension. For example,
ENABLE adds “WPF,” DBASE adds “DBF, NDX,
FRM, and MEM,” LOTUS adds “WK1, PRN, and
It is important to devise a naming scheme that is
comfortable for you. Your command may have already
addressed this area and come up with descriptive
naming conventions. If so, of course, you will use
those. Whatever method you use, be sure that it is
indeed a method and NOT just haphazard naming of
files. When working alongside the end users, be sure to
pass along what you have learned. When they go to the
filing cabinet, be sure they know exactly which file
drawer to open and which file folder to retrieve from
that drawer. Most people are familiar with organizing
file folders in the drawers of a filing cabinet. You might
want to use this analogy as a starting point, explaining to
the users how they can organize their disk files in much
the same manner. Explain how they can organize their
work (files) into groups of files called directories.
Figure 2-16.—Unstructured disk file directory.
categories: files that deal with user applications and
those that deal strictly with division matters.
Using the tree-structured approach, you can divide
your disk into smaller units by subdirectories, as shown
in figure 2-17. In this example, E5 Christmas, as the
primary user of these files, decided to organize her files
by setting up a separate directory called
directory, she set up several subdirectories. They are
identified by <DIR> following the name and they have
no extensions. Notice also that some files, those that
relate to division matters, are included in the
subdirectory along with the subdirectories that relate to
user files. Because E5 Christmas uses the division files
frequently, she wanted to be able to access them directly
from her directory.
File directories, like the folders that are filed away
in drawers by category, or like the yellow pages of the
phone book, provide you a way to organize and find
files by category and name.
Most operating systems give you the option of
creating either single or multiple-file directories,
regardless of whether your system uses floppy or hard
disk. Disks with only one directory are said to be of the
unstructured or flat type. Disks having more than one
directory are said to be hierarchical or tree structured
because they contain a root directory and several
subdirectories, each subdirectory containing files with
common subject matter. We use the term tree structure
because this type of directory takes on the appearance of
an upside down tree with the trunk of the tree or root
directory located at the top and all the branches or
subdirectories located below.
Subdirectories, like other files, appear as entries in
the directory; however, you can’t see a listing (or a
display) of all the files in all the subdirectories at one
Let’s assume you have a floppy disk that contains 50
files with only a main or root directory, as shown in
figure 2-16. Upon displaying the directory (using the
DIRectory command), you notice the files are listed in
random sequence, usually in the order of their creation
or when last updated. We call this an unstructured
directory. Looking more closely, you realize a number
of things. First, that better organization is needed.
Second, that most of the files listed can be grouped
together by categories: supply, 3-M, personnel,
disbursing, food services, and division management.
Finally, you see that there are really two types of
Figure 2-17.—Tree-structured disk file directory.
must follow to find a given directory/subdirectory or
file name. In example B in figure 2-18, to locate the
file named DIN-MENU.DLY, the path is
time. Instead, you must look at each subdirectory to see
what is in that one. If E5 Christmas wants to see what
files are in the subdirectory SUPPLY, she would use the
DOS command to change the directory name to
SUPPLY and then display its directory (figure 2-18,
example A).
Once you have grouped related files into a
subdirectory, you can act on them as a unit. The DOS
file-handling commands can be applied to an entire
subdirectory of files in a single stroke. For example, you
can issue commands to copy, print, or delete all the files
in a subdirectory as easily as you can for a single file.
Other files on the same disk, but in different directories
go unused and undisturbed. Subdirectories are
especially helpful when working with hard disks
because of their large storage capacities.
As the number of files on a disk increases, so does
the need to have a disk that is well-organized. A wellorganized disk can save you a considerable amount of
time and frustration in locating files. As computer
specialists, we know this is true and of great importance,
but to the uninformed or new user who has not been
properly trained, disk management may seem very
cumbersome and time consuming. Some users may not
even be aware that they can organize their files on disk,
and that’s where you come in. How can you help users
create and use a tree-structured directory? you might
To learn more about DOS directory structures and
commands, read the DOS reference guide that
accompanies the DOS software.
Whenever you format a disk, a single directory
called a root directory is created. You can then instruct
DOS to create or MaKe other DIRectories, using a
command such as MKDIR or just plain MD. These are
called subdirectories. Further, a subdirectory can have
other subdirectories. Directories, regardless of their
level, are given names just like any other files. DOS
keeps track of each directory the same way it does your
files. Using various DOS file handling commands, you
can create (MKDIR or MD), change (CHDIR or CD),
and remove (RMDIR or RD) directories and
subdirectories. To move through the tree structure (UP
or DOWN), you must issue commands that use a
path name. A path name is a list of the directory(ies)
(which might end with a file name) that DOS
Backing Up Files
You have heard it before, and you are going to hear
it again here: BACKUP your programs and data files.
If you don’t, you will eventually lose all or part of your
data, and the only person you can blame is yourself.
Data can be lost or damaged in a number of ways.
Common causes of data loss are power surges and
drops, power failures, and user errors. User errors top
the list. Less common but potentially disastrous are fire,
theft, vandalism, and natural disasters.
How often have you come close to erasing a file or
formatting a floppy or hard disk by accident? Probably
more times than you care to admit. No matter how many
precautions you take, you can’t prevent all the potential
ways data can be lost. You can certainly reduce their
adverse effects by backing up your files on a regular
When working with data files, you will want to back
them up at least on a daily basis either to tape, diskette,
or to another hard disk. For our example, we will use
two diskettes. A technique referred to as the odd/even
backup uses two diskettes. Label one diskette as odd
and the other as even. When you make your backups,
use the odd diskette on odd days, and use the even
diskette on even days. This pays off when you find that
errors were inadvertently made to a file the day before,
and you backed-up that file onto your backup diskette.
With this system, you can go back 2 days if needed.
No matter how many backups you make (two,
three, or one for everyday of the week) or what method
you use to make them, they are worthless if they are
Figure 2-18.—Examp1es of files in subdirectories.
and place the new one on. Never stack labels one on top
of the other on a diskette. It may cause problems when
you insert the diskette into the drive.
destroyed along with your microcomputer. You need to
make multiple backups and store a set in a different area
away from your working area or, at a minimum, in a data
safe. This will require some extra effort by you or the
user, but it will more than pay for itself should you ever
experience a data loss.
Show end users how to handle and properly use
diskettes. To be used, a diskette must be inserted into a
disk drive. Sounds simple enough; however, if you
were to measure a 5.25-inch diskette, you would find
that each side measures 5.25 inches—it is perfectly
square. To the end users, inserting a diskette into a drive
could become a bit of a problem with eight possible
ways to insert it. We know a diskette goes into a drive
correctly in only one way. If the disk drive is the
horizontal type, insert the diskette with the label facing
up and the recording window toward the drive door, as
shown in figure 2-19. Normally, if the disk drive is the
vertical type, hold the diskette with the label facing left
while inserting it with the recording window toward the
drive door. Once the diskette is properly inserted, close
the drive door by lowering the drive latch. This
positions the read/write heads and locks the diskette in
place. This locking step is necessary; otherwise, the
system will not be able to access the diskette in the
Care, Handling, and Protection of Diskettes
As communications specialists, we know how
sensitive diskettes are when it comes to rough handling,
extreme heat and cold, high and low humidity, static
electricity, and contaminants, such as dirt, dust, liquids,
and grease. Unfortunately, many end users do not. They
may leave their diskettes lying around out of their
protective envelopes, expose them to direct sunlight,
store them next to an electric pencil sharpener, and so
on. It will be your job to explain and demonstrate to new
users how to properly manage and maintain their
diskettes as well as other types of magnetic media.
Because diskette mistreatment is usually fatal to
data, it is important to have procedures to help the end
user better understand how to care for, handle, and
protect diskettes. They must be made aware that once a
diskette is damaged, there’s little chance of retrieving
the data. If you were to calculate the value of a single
diskette in terms of the data stored on it and the hours it
took to input the data, then a $2 diskette might well be
worth several thousands of dollars. If you can make the
end users understand this, then maybe they will treat
diskettes more carefully. Go over the fundamentals on
how to care for, handle, and protect diskettes. Explain
how to properly load a diskette into a drive.
times have you read or heard the following “Whenever
diskettes are not being used, they should be stored in a
protective envelope”; or “Whenever a diskette is
removed from its protective envelope, never touch any
of the diskette’s exposed parts”; a thousand times
maybe? The same may not be true of individuals who
have just been introduced to the world of computers. It
will be your job to assist and educate these new users
through OJT in their working environment.
DISKETTES.— We know how important it is to keep
diskettes away from cigarette smoke, greasy foods, and
beverages that might be spilled on them, but what about
the end users? Do they know the negative effects these
substances can have on their computer, the media, or
their work? Probably not, and that’s where you come in.
Temperature and humidity are also important.
Never leave diskettes in direct sunlight or in areas where
humidity is extremely high or low. High humidity can
cause moisture to form on the diskette’s surface or
possibly warp the diskette’s protective jacket. Low
humidity makes conditions ideal for the buildup of
static electricity, which you can transfer or discharge to
a diskette, thereby destroying the data. Diskettes are
designed to withstand temperatures from 50 to 125
degrees Fahrenheit, 10 to 52 degrees Celsius, and a
Never bend or fold diskettes. The diskette drive
only accepts a diskette that is absolutely flat. If it is bent
or crinkled, it may cause severe damage to the
read/write heads as well as make the data unretrievable.
When preparing an external file label, never use a
pencil or ball-point pen if the label is already affixed to
the diskette’s jacket. Instead, use a felt tip marker and be
sure to press lightly. Unless labels are scarce, you
would do well to inform the user it is far better to prepare
a new label before placing it on the diskette. Then,
using extreme care, remove any label on the diskette
Figure 2-19.—Inserting a diskette properly.
relative humidity of 8 to 80 percent. However, we in the
computer community try to keep all magnetic media
within a temperature range of 60 to 80 degrees
Fahrenheit, and a relative humidity of 30 to 60 percent.
Generally speaking, a temperature and humidity in
which you are comfortable will also be comfortable for
low-pressure air or canned air (a harmless gas under
pressure), as this cleaning method has a tendency to
blow dust and dirt into cracks, crevices, and electrical
components that could eventually cause you problems.
The display screen needs routine cleaning. A dirty
screen can be hard to read and may contribute to
headaches and fatigue. You will be able to see the dirt,
dust, and smoke buildup on the screen. The dust can
cause static electricity that may result in lost data. You
may use a liquid video spray cleaner, but do NOT spray
it on the screen. Spray it on a lint-free nonabrasive
cloth. A word of caution. Many commercial cleaning
solvents contain alcohol and other flammable agents. If
your display screen is on (energized) when it is cleaned
with one of these flammable fluids, combustion can
occur. An energized display screen can discharge quite
a bit of static electricity-—a sufficient amount to ignite
alcohol. So, if you intend to clean your screen, turn the
monitor OFF first. Also available are wet/dry
towelettes. These are convenient to use because the
cleaning solution is normally premeasured and they
come in individual packets. To reduce static electricity,
special antistatic sprays are available, or you can use
antistatic pads or mats. Some cleaning solutions
include antistatic chemicals. An antistatic filter for the
display screen is another way to reduce static buildup.
Antistatic dust covers may also help when the system is
not being used.
The users must also be made aware that they are to
keep all types of magnetic media, including diskettes, at
least one foot away from anything that generates a
magnetic field. This includes magnets of any kind, such
as those found in telephones, stereo speakers, and paper
clip dispensers, as well as magnets on copyholders and
inside of printers. It also includes motors, such as those
found in portable fans and floor buffers and polishers.
System Care and Operator/User Maintenance
The fact that microcomputer systems are small and
out in the workspaces doesn’t mean they don’t need
operator maintenance. They do. Dirt accumulates on
diskettes, disk drives, printers, display screens, and
keyboards. Static electricity can also be a major
problem, especially in areas where humidity is low.
Keep your system as clean as possible. One way to
do this is by using dust covers. This, of course, only
protects the system when it is not in use. You will still
need to clean the components on a regular basis.
Clean the floppy disk drive heads with a head
cleaning diskette. It is easy to do. Read the directions
that come with the head cleaning kit. They may have
you put fluid on the cleaning diskette. Then you insert
the cleaning diskette in the drive and activate (lower)
the heads for a few seconds. This helps reduce service
calls, and you are less likely to lose data. How often you
will need to do this will depend on how much the system
is used and whether the area is very dusty and smokey.
Some floppy disk drive manufacturers recommend
cleaning the heads no more than twice a year. As your
subject matter experts (SMEs), we recommend
cleaning the heads after 40 to 50 hours of actual use.
Printers create their own bits of paper and dust. To
clean the printer, use a vacuum designed to clean
computer components. These vacuums are usually
portable, have a dual filtering system, and can clean in
small, hard to get places. Cleaning solutions and
specially shaped brushes are available for cleaning
platens. For cleaning the print heads, you can feed a
specially designed print sheet cleaner through the
printer just like you feed continuous-form paper. Laser
printers have special cleaning requirements. You use
dry lint-free clothes to wipe any residue of surfaces and
a cleaning brush to clean the antistatic teeth.
To clean keyboards, you can use specially angled
swabs with cleaning solution, and/or a portable vacuum
that has special attachments to reach between keys.
Vacuums of this type usually have dual-filter systems to
keep from blowing dust and dirt back into the room.
Ultra soft, thin bristle brushes are also available for
cleaning keyboards. We do not recommend you use
Operator/user maintenance is important for
effective operation of computer systems. It helps
prevent data loss and will increase the life of the
computer system and its components. Establish a
schedule for routine operator/user maintenance.
tape unit). Then, by depressing the proper control panel
keys/buttons in the appropriate sequence, the tape unit
automatically threads the tape by using a vacuum to pull
the tape into the vacuum column past the read/write
head assembly onto the machine take-up reel and
advances to the load-point (BOT) marker.
Loading and Unloading Tapes
When you are loading or unloading (mounting or
dismounting) a magnetic tape, look for tapes with
irregular windings and reel warpage. You will see that
as tape is wound on a reel, it is normal for some of its
edges to protrude slightly. These irregularities usually
result from high-speed rewinding. The terrific speed at
which tape moves during a high-speed rewind produces
the slightly irregular winding caused by air being
trapped between adjacent layers of tape. This, in itself,
will not cause improper operation of the tape, but it does
require you to use good judgment and extreme care
when handling tapes.
Tape Cartridges.—Tape cartridges are even easier
to load. Tape cartridges consist of a reel of tape and a
take-up reel enclosed in a protective case similar to the
cassette tapes you are familiar with, only larger. Here,
you simply mount the entire tape cartridge on the tape
unit and depress the proper keys/buttons. The tape
automatically loads. Your hands never come in contact
with the tape. The cartridge type of tape unit also works
under vacuum control and threads the tape in the same
manner as self-loading tape units.
MOUNTING A TAPE.— When you mount a tape,
make sure the tape unit is not being used for another job.
Check to make sure you are mounting the correct reel of
tape according to job requirements. Tapes have external
labels that identify the data or programs on them.
Remember, if the reel of tape is an input, be sure the file
protection ring is removed. If the tape is an output, be
sure a file protection ring is inserted. Then proceed to
mount the tape. Have one of the more senior operators
on the system show you how to perform this operation
because mounting a tape and depressing the proper
keys/buttons differ from one system to another.
Basically, you will place the reel on a hub and lock the
reel in place. Then you thread the tape through the
read/write head assembly onto the machine take-up reel
(unless the tape unit is a self-loading tape unit). Once
the tape is properly loaded, the ready light comes on.
DISMOUNTING A TAPE.— When a job finishes
using a tape, the tape is normally rewound and unloaded
automatically. At that time, the ready light goes off.
This is an indication to you that the tape can be
dismounted and placed in its proper storage rack or
returned to the media library.
LABELING A TAPE.— In some installations, you
may be required to prepare the external tape label for an
output tape file. On it, you will indicate such
information as the following:
l The tape unit number (or drive number) where
the tape file was initially created
If the tape is not properly seated on the tape unit’s
hub during use, it will wobble or appear to be warped. If
the file protection ring is not completely inserted, this,
too, can produce the same effect. In either case, the reel
behaves like it is warped, and upon rewinding, the edges
of the tape can become badly damaged.
l The date of creation
l The job name or number
l The identification or volume number
Self-Loading Tapes.— The use of self-loading
tapes makes tape loading much easier. Self-loading
tape units eliminate the need for you to manually thread
a tape between the read/write head assembly onto the
machine take-up reel. All you need to do is to mount
(place) the reel of input or output tape on the file reel hub
and allow a small strip of tape to extend from the reel
(anywhere from 2 to 6 inches, depending on the type of
e The tape usage data and other pertinent
STORING TAPES.— When not being used, tape
reels should be properly supported. The plastic canister
or tape strap is designed to fully support the reel. A tape
reel that is supported in any other manner may become
right-hand tractors, you must use the tension control
(figure 2-21). This allows you to move the tractors to
the desired location. As you become more experienced,
you will know where to position the tractors for all
standard form widths. You then place the form over the
sprockets and close the tractors.
FORMS.— Many printers have a soundproof cover that
you must raise to gain access to the forms tractors and
other manual controls. By moving the print-unit release
lever toward you (figure 2-20, frame A), you unlock the
print unit assembly. This allows you to swing the unit
out to the side and gain access to the upper and lower
forms tractors (figure 2-20, frame B). You then open all
four tractors to unload or load paper forms.
Now that the forms are in place, you apply the
proper amount of tension to the paper. To do this, use
the tension control (figure 2-21). By depressing the left
button, you move the right-hand tractor closer to the
left-hand tractor, thereby decreasing the amount of
tension to the paper. By depressing the right button, you
move the right-hand tractor farther away from the lefthand tractor, thereby increasing the amount of tension
to the paper. If there is not enough tension, the forms
tend to feed improperly, and they may tear. If too much
tension is applied, the tractor latching pins tend to rip
out the sprocket holes in the form and may cause the
forms' tractors to open. Once the proper tension is
applied, you can proceed to align the forms so that the
information will print in the correct location, both
vertically and horizontally.
Unloading Forms.— To remove forms already in
the printer, tear off the form at the end of the report and
let the unused portion fall back into the box. The printed
portion will normally follow on down into the printer’s
stacker. Now, you are ready to insert (load) a new form.
Loading Forms.— Quite often, you will find
yourself having to load a form of a different width. To
do this you will have to adjust the tractors. When
adjusting the tractors, it is a good practice (and
sometimes a command policy) to keep the left-hand
tractors in one permanent location. In this way, both
you and the programmer always know where print
position 1 will print on any given form. To adjust the
Figure 2-20.—Open the print unit to access the print unit and
forms tractors.
Figure 2-21.—Tractor and tension control adjustments.
control is especially useful when working with
preprinted forms, such as your LES statement. Now
that the form is positioned horizontally, you can make
the necessary vertical adjustments.
Aligning Forms.— Most high-speed impact
printers are designed with a ribbon shield. This ribbon
shield protects the form from coming into contact with
the printer ribbon, thus eliminating ink smears. It also
serves as a print line indicator, which we use to align the
form. The ribbon shield swings in front of the form
(figure 2-22, frame A). Once the ribbon shield is in
position, it can be used as illustrated in figure 2-22,
frame B, to help in the adjustment of the form. Use the
horizontal adjustment control shown in figure 2-23, to
slide the entire print mechanism to the left or right.
When the left margin of the form is even with the first
ruled line on the ribbon shield print line indicator (figure
2-22, frame B), release the horizontal adjustment
button. At this point, the horizontal printing is accurate
to within one print position. Use the horizontal
adjustment button (figure 2-23) for any additional fine
horizontal adjustments that may be necessary. This
Again, using the ribbon shield print line indicator as
a guide, you can move the form up or down one line at a
time until the form is vertically aligned by pushing the
line feed button. Use the vertical print adjustment
button (figure 2-23) for any additional fine vertical
adjustments to align the print line to its proper position.
Now that the form is vertically adjusted, close the print
mechanism and lock it into place with the print-unit
release lever.
Print forms not only vary in size but in thickness as
well. For this reason, you will have to adjust the printer
to accommodate for thickness differences. To do this,
you move the form thickness control knob (figure 2-23)
either left or right. This will move the print unit
mechanism closer to or farther away from the print
hammers, thereby giving the forms sufficient clearance
to pass between these two components. The paper
Figure 2-23.—Vertical and horizontal alignment controls used
to adjust printer paper.
Figure 2-22.—Using the ribbon shield for alignment.
Troubleshooting and Isolating Problems
thickness control knob has a direct effect on the printer’s
phasing (which has to do with the quality of the printed
character). For this reason, it is important that this be set
Problems will range from simple to disastrous. The
printer may not be printing because it is out of paper.
The disk drive may not be reading because the drive
latch is not closed. The printer maybe printing garbage
because the incorrect printer definition is used. The
hard drive may be having excessive read errors. The
problems may be operator/user errors, software
problems, or hardware malfunctions. Knowing
which is sometimes easy. Under other conditions, it
may be difficult to determine the source of the problem.
Once you become familiar with the various buttons,
levers, and controls of anyone of the many printers you
may be working on, you will quickly find that most
forms are relatively easy to align. For those that are not,
such as preprinted forms, often the programmer will
assist you by printing out form alignment characters to
allow for proper alignment before the actual printing of
the job.
TROUBLESHOOTING.— Learn about common
problems. For example, what does it mean if the
monitor screen goes blank? Is the problem a simple
one, such as the monitor has an automatic function that
turns off the screen when it hasn’t been used in a
specified amount of time? Pressing any key will
reactivate the screen. Or, have the brightness or contrast
thumbwheels been turned, causing the screen to look
blank? A turn of a thumbwheel may bring the monitor
screen back to light. Has a cable become disconnected?
Has the power been turned off? Is the monitor or power
strip unplugged? Or, is the power supply no longer
working? Has the operator hit a combination of keys by
mistake that has caused the screen to go blank except for
the status lines? Look at the status lines to see if they
provide information. Whatever the symptoms, look
first for simple logical answers. Check all cable and
outlet connections. Check to see that each component
of the system is plugged in properly. Check to see that
the proper options are selected. For example, on the
printer, is it in a ready status? Are the proper dip
switches set? Is the printer out of paper? Is the correct
mode of operation selected, either through the buttons
on the printer or through software? If the software and
hardware allow using several printers, is the correct one
selected, and are any manual selections made when a
switch box is used?
maintenance contract is usually carried on the printer,
you are still responsible for part of the routine
maintenance. Keep the exterior and interior of the
machine clean using a vacuum cleaner wherever
possible. Check the print mechanism for carbon and ink
buildup that accumulates and eventually causes
problems. And most importantly of all, change the
printer ribbon as often as needed. When the print starts
to fade and adjustments to the form’s thickness and print
density controls do not seem to help, then it is time to
change the printer ribbon.
It is a good practice to get into the habit of
performing a test print before starting a job, especially if
the job is a lengthy one. A test print is a routine designed
to show you whether the printer is functioning properly:
that each and every character is clear and sharp (not
chopped or halved), that all characters are uniform
throughout the entire print line (not wavy), and that all
print hammers are firing properly.
You should now have a basic understanding of, how
to remove, load, and align forms in the printer; setup the
required print controls; be able to respond to the various
machine indicators; and perform routine operator
maintenance functions.
We could go on and on with examples. The point is,
learn from experience. Keep a list of symptoms,
probable causes, and ways you can use to trace a
problem to its cause. This will help you to diagnose and
troubleshoot problems. You will find users tend to
make the same mistakes over and over, especially while
learning. Help them by telling them about common
problems, the reasons for the problems, and ways to
avoid having them happen to them.
Reduce File Fragmentation
File fragmentation occurs when you delete a file,
leaving, basically, a hole in the information on the hard
disk, or when you add information to an existing file
when there is no contiguous space left next to the file.
To correct fragmentation, you can make a backup,
reformat the hard disk, and restore your files. You can
also run a software program referred to as a
defragmenter to reorganize the files so the data in each
file is contiguous.
You will soon learn the common errors, keep a
mental list of the sequence you use to start isolating a
problem. You may want to develop a checklist. For
Table 2-1.—Checklist for Identifying Problems
example, look at the list in table 2-1. These area few
examples to get you thinking about problems. Look at
the condition and try to determine possible causes.
Look in the documentation; it usually has a section that
lists conditions and possible causes. Ask the users what
program they are using. Ask the users what keys they
depressed and in what sequence. Ask what they were
trying to do. Always check for error messages. Check
any status information on the screen. You might want to
develop a separate list for each component or for each
software package. You might add to the lists in the
documentation. Diagnostic routines can also help you
find problems.
DIAGNOSTIC ROUTINES.— Most microcomputer systems come with online diagnostic routines.
These are tests you run from the keyboard. They are in
addition to the diagnostic tests the system automatically
runs when you turn it on. Your system will probably
provide a disk read test, a keyboard test, memory tests,
and a power-up test. The diagnostic program will tell
you what commands to use to perform each test, what to
look for, and how to stop each test.
In this chapter on computer center operations, we
covered trouble reports, computer system output,
environmental conditions, console operations, virus
protection software, AIS requests, and the media
library. This is but a sampling of what will be expected
of you as you enter the computer center. You will build
on this foundation with the skills you have and those
you will learn.
A major hardware failure could prevent the system
from being able to display error messages on the display
screen. Should this happen, your microcomputer
system unit may have diagnostic light-emitting diodes
(indicator lights) to help isolate the problem. Follow the
instructions in the owner/user manuals.
Upon completing this chapter, you should be able to do the following:
l Explain how to convert, process, transfer, and verify data files.
l Describe how to input and manipulate data on a computer system.
l Calculate storage and memory requirements for computer systems and data.
l Explain how to perform software configurations and how to install and
upgrade software.
l Review I/O file specifications and determine system I/O requirements.
l Explain how to analyze the requirements, review the structure, identify the
problems and change the structures of databases.
Data management incorporates many aspects of
data manipulation and inputting, calculating storage
and memory requirements, and computer software.
You will need to know how to install applications
software so it works and be familiar with all types of
productivity software. Database management
techniques will aid you in understanding how databases
are analyzed, how to review and change structures, and
how to identify problems.
locating, accessing, outputting, and maintenance of
data files. Can you imagine yourself trying to keep
track of the location of all data files, which disk pack
each is on, and which disk pack is mounted on which
online disk drive. To try to do this would be
overwhelming. Thanks to data management routines,
you are relieved of this responsibility.
The converting, transferring, and verifying of data
files is left up to the operator to perform. All of these
processes are completed by the use of application utility
programs. The transferring and verifying of data files is
accomplished by using a copy utility. Data file
conversion is accomplished by a utility of the software
program being used, such as converting a
WordPerfect® file into a Microsoft® Word file.
Data administration is an ongoing concern of
management. Data administration encompasses all the
technical and management duties required for
converting, processing, transferring, verifying, and
inputting data. Over the years, data resources in the
Navy have grown in size and complexity. It is apparent
that not all of the data problems within the Navy are
resolved with the use of software. Some are taken care
of with hard work.
There are several different ways to accomplish the
inputting of data into the system. The oldest technique
is data entry, keying the data off of source documents
straight into the system. The most common ways are
inputting the data from a tape or disk file. These files are
produced from another job or from another installation,
such as status of supply parts.
Data management programs or routines are
concerned with reading and writing data, locating data
files, controlling I/O devices, handling I/O errors and
requests, and providing space on output media for new
files. In short, data management routines oversee the
Once the data is inputted into the computer system,
we have the capability of manipulating the data by
copying, appending, deleting, and editing it. Copying
and appending are used primarily for manipulating
convert the artificial languages used by programmers,
such as COBOL or FORTRAN, into a machine-usable
code after it is entered into the computer.
entire data files, while deleting and editing are used for
individual records in a data file.
Up to now, we have been discussing computer
hardware (the computer and its peripheral devices) and
the manner in which these devices work and are able to
talk (communicate) with each other. But what about
this thing called software? Do we really need it? We
most certainly do! Software plays a major role in data
processing; for without software, we could not direct
the computer to perform simple addition. It’s the
software that makes everything happen. Or, putting it
another way, it brings the computer to life. At this point,
we briefly describe the general types of software used in
Utilities are programs or routines that have general
application. They may be separate programs or they
may be routines or programs included with the
operating system to further aid the user by performing
standard functions. Sort, merge, and copy programs are
typical examples. Other examples are text editors to
allow programmers to enter, add, delete, or change
program statements; linkage editors to put together
compiled programs and routines; and debug routines to
help programmers find errors.
Software can be defined as a set of computer
programs, procedures, and associated documentation
concerned with the operation of a data processing
system. Basically, there are two types of software:
systems software and applications software.
Applications software consists of programs
designed to solve specific classes or types of problems.
For example, word processing programs help us prepare
correspondence, instructions, messages, and so on.
Spreadsheet programs enable us to store and manipulate
numbers in numerical tables. Database programs
enable us to store and retrieve large amounts of data in
various report formats. Some software is ready to use
and may be purchased from retail stores and
government contracts. This software is called off-theshelf software (COTS). If COTS is not available to
solve Navywide or individual user problems, the Navy
may write its own programs. Some programs are
designed and written by one of the Navy’s central design
agencies and distributed to AIS installations for use. If
no Navy-developed software will solve an individual
problem, you or your automated information system
(AIS) installation may write a program in one of the
many programming languages.
Systems software, often referred to as systems
programs, consists of supervisory and support modules
(programs) designed to coordinate the capabilities of
the computer itself. These include programs such as
operating systems, assemblers, debug routines, text
editors, compilers, library maintenance routines,
utilities, linkage editors, and I/O drivers.
Operating Systems
An operating system is a collection of many
programs used by the computer to manage and control
its own resources and operations. These programs
control the execution of other programs. They
schedule, assign resources, monitor, and control the
work of the computer, allowing it to carry out tasks
independently of most human intervention.
Almost any type of application you can think of can
be programmed in one or more of the many
programming languages. Just as we humans speak in
many different languages, computers also speak (use)
many different languages. We can divide programming
languages into three categories: machine languages,
assembly languages, and high-level languages.
Assemblers and Compilers
Both assemblers and compilers are language
translators. They are usually designed for specific
machines and specific languages. They translate
computer programs written in assembly language into
machine language. A language translator for an
assembly language is called an assembler program.
Most high-level language translators are called
compiler programs. These translators are designed to
Machine Languages
A machine language consists of a combination of 0s
and 1s that is used to indicate OFF and ON states of
programs. Therefore, it is a general-purpose,
introductory language that is fairly easy to learn and to
use. With the increase in the use of microcomputers,
BASIC has regained popularity and is available on most
microcomputer systems. BASIC is the acronym for
Beginner’s All-Purpose Symbolic Instruction Code.
electricity. All data and instructions are represented
(written) in a binary form. This is the ONLY form the
computer is able to understand. Each computer has its
own machine language; therefore, a program written for
one computer type cannot be transferred to another type
of computer system. Writing programs in machine
language code is time-consuming and requires the
programmer to specify each operation code and the
specific location for each piece of data and each
PASCAL.— Pascal is a language designed to teach
programming. It is fairly easy to learn; yet it is a more
powerful language than BASIC. Although Pascal is not
yet a standardized language, it is still used rather
extensively on microcomputers. It has greater
programming capabilities on small computers than are
possible with BASIC. It is used by many colleges and
universities. It is named after Blaise Pascal, a
mathematician and the inventor of the first mechanical
adding machine.
Assembly Languages
We use assembly languages to avoid having to code
directly into machine code (0s and 1s). Assembly
languages use symbolic codes called mnemonics to
represent operations. For example, the letter A could be
used for add, and the letters ST could be used for store.
Although assembly languages are more user-oriented
than machine languages, they are still quite complex to
work with as a programmer. Assembly languages are
generally used by systems programmers to design and
maintain operating systems and other systems software
where speed of operation and conserving storage are
more important than programmer time.
ADA.— Ada is a modern, general-purpose
language designed with the professional programmer in
mind. It has many unique features to aid in the
implementation of large-scale applications and realtime systems. Its development was initiated by the U.S.
Department of Defense (DOD). It is named to honor the
achievements of Ada Augusta Byron, Countess of
Lovelace, who was a supporter of and collaborator with
Charles Babbage, the first person to propose the concept
of the modern computer. She suggested using the
binary system of storage instead of the decimal system
and developed the concept of a loop to execute
repetitive instructions. Babbage is known as the father
of the computer, and Ada Lovelace is considered the
first programmer.
High-Level Languages
A whole host of high-level programming languages
have been developed to solve one particular class of
problems or another. High-level languages were
developed to allow you, as a programmer, to work in a
language that is close to English or mathematical
notation, thus improving overall efficiency and
simplifying the communications process between you
and the computer. These high-level languages allow us
to be more concerned with the problems to be solved
rather than with the details of computer operation.
Examples of high-level languages include COBOL,
FORTRAN, BASIC, Pascal, Ada, and C++.
C++.— C++ is a general-purpose language that
works well with microcomputers. It is useful for
writing both operating systems and database programs.
The programs are portable, which allows them to be run
without change on a variety of computers.
COBOL.— COBOL was developed for business
applications. It uses everyday English-like statements
and is good for handling large data files. COBOL is the
acronym for COmmon Business-Oriented Language.
Depending on the needs of the users, the software
will vary from command to command. But one thing is
for sure, your system will have a disk operating system
to make the whole thing work. Beyond that, you may
have users who run only wordprocessing, or only
database management applications. Maybe they use
graphics and do desktop publishing. Maybe all their
applications are accounting, and they rely primarily on
spreadsheet programs and specialized accounting type
programs. Some may even be writing their own
programs in languages such as PASCAL, BASIC, or
COBOL. It may be your job to help users install, learn,
FORTRAN.— FORTRAN was developed for
mathematical and scientific work. It is used by
engineers, scientists, statisticians, and others in areas
where mathematical operations are most important.
FORTRAN is the acronym for FORmula TRANslator.
BASIC.— BASIC was designed as a teaching
language to help beginning programmers write
and effectively use one or more software packages or
programs. It may be your job to develop specialized
programs or routines for your installation or for users in
their own work spaces. In the following sections, we
will discuss installation and use of a few of the general
types of software we commonly associate with
sure you use a felt tip pen if you are writing on a label
already attached to the diskette.
Once you have the operating system copied and
installed, put the original distribution disks in a safe
place. Now, you are ready to use the computer; or are
you? Chances are you will need more than the operating
system. The operating system is great. It has many
useful commands like COPY, DELETE, FORMAT,
BACKUP, and soon. It will even have an editor, usually
a line editor, that allows you to create files and edit them
line byline. However, its primary jobs are to manage the
system and its resources (disks, printers, and soon), and
to help you communicate with the computer to use other
programs (applications software).
User/Applications Software
Operating System
When you install a user/application software
package on a system, you need to provide the software
with information about your microcomputer
configuration. Because there are so many different
software packages and programs available and each one
has different requirements, we will not go into a lot of
detail. Remember, refer to the documentation, it should
provide what you need to know. Many of the manuals
lead you through step-by-step. The following example
should give you a good idea of what is involved. We
have selected a wordprocessing program for our
example because most installations will have a
wordprocessing package.
The operating system will be the first program you
will need to know about because you must install it
before other programs. It manages the operation of the
If the system has a hard (fixed) disk, you will install
the operating system onto it. The first step will be to
partition the hard disk; that is, identify the hard disk to
the operating system and create a partition for the
operating system. Partitioning is the process of dividing
the hard disk into smaller drives, which will allow you
to use different operating systems, such as DOS or
UNIX. Next, you will format the hard disk, prepare it so
it can be used. The operating system will ask a question
similar to, “Are you sure you want to format the hard
drive?” before it proceeds with the format. Then, copy
the operating system files from the distribution disks
onto the disk. You must follow the steps in the
owner/user manual. It may tell you to use a setup
command that will lead you through the process from
the display screen. Once it is installed, everytime you
turn on the system, the operating system will load from
this partition.
MASTER) DISKETTES.— The first thing you should
do is copy the files from the distribution diskettes. Each
software package may have several diskettes. If you
have a hard drive system, you may copy the files from
the distribution diskettes to the hard drive using the
copy command in the operating system. First, setup the
name of the directory in which you want to store the
files. Then, copy them to the hard disk. If your system
has no hard drive, copy the files to other diskettes. Most
operating systems have a copy command that allows
you to copy all files on a diskette with a single
command. This is called a wild card copy. The copies
will become your working copies. Prepare external
labels for the working copies. Store the distribution
diskettes in a safe place away from the microcomputer
in case you need them in the future.
If the system has only floppy disk drives, you will
make copies of the distribution disks onto new
diskettes. If the new diskettes are not formatted, you
can use a command (such as DISKCOPY) that will
format and copy. Again, follow the instructions from
the startup or getting started section of the owner/user
manual. If there is a setup command, use it to lead you
through the process. Be sure to prepare external labels
with the name of the operating system. Write the serial
number if there is one, and write WORKING COPY. Be
the user manual with installation instructions next to the
microcomputer and follow the step-by-step procedures.
Make sure you complete each task successfully before
going onto the next.
files, take care of the system, and perform user/operator
maintenance. Don’t be surprised when you get your first
call for help. As you have learned, computers seem to
have minds of their own and can do strange things. Help
users by troubleshooting and identifying problems.
Teach them what you know.
The first step will probably be to execute the
program from a setup disk or in a setup mode. You will
probably execute a command that will lead you through
a series of prompts and menus on the display screen.
This will allow you to tell the program about your
system and make initial settings. These settings will
define your system and set the defaults. This means
that everytime you execute the program, the settings
will be what you specified. You will not have to reset
them each time. For example, you might be asked
whether you want the software to automatically backup
your data. If you enter yes(y), it will ask you how often,
every so many minutes. You enter the number. It may
give you a choice of whether you want a beeper set to
alert you to a given condition. For example, the system
can be told to beep when certain error conditions occur.
If the software is a wordprocessing program, you will
want to specify the margin settings you normally want;
for example, left margin at position 10 and right margin
at position 75. You might want to tell it to automatically
right justify print and to format date as mm/dd/yy. You
can tell it whether the default setting for paper type
should be continuous-form or single sheet; and so on.
Once you have established the defaults, you will not
have to change them unless you want something
Using Software
Once you have the software installed and set up so it
works on your system, the system is ready for use.
Simple enough, you say—so what should I do first?
You should boot either from the hard drive or by
inserting the diskette that contains the operating system.
You can set up the system so it will automatically boot
when power is turned onto the system. Next, tell the
operating system which program to use. Do this by
entering the file name of the program following a
prompt given by the operating system. For example, if
the program is named WPP (for wordprocessing
program), enter WPP and press the ENTER (RETURN)
key. If you are using a hard disk, be sure to specify the
directory used when you installed and set up the
program. The operating system will then load the
program into memory and the system is ready to do the
work. From this point on, follow the instructions of the
software package; in this example, a wordprocessing
program. Refer to the user manual and any in-house
user manuals that apply.
You may also need to tell the software what type of
printer you will be using. This will enable the program
to send the proper signals to your particular printer. You
may be able to define several printers and select the
appropriate one when you use the software. Some
software packages come with definitions for many
printers, and it is a simple matter to tell it which you
have by selecting the make and model number from a
When you have finished your processing, return to
the operating system before turning off the power. Do
this by saving your work and exiting the program
properly. Each program will have a procedure or
command to end execution of the program and return to
the operating system. If using diskettes, remove them
from the drives, put them in protective jackets, and file
them in an appropriate place. If using a hard disk drive,
it is considered good practice to enter the operating
system command to park the read/write heads. This will
move the heads away from data storage areas so data
will not be destroyed if the system is moved or
accidentally bumped. Then turn the power OFF.
Occasionally, you will need to upgrade the software
that you have loaded onto the computer. To do this, you
will follow the same procedures that you did when the
software was originally loaded. That is, read and follow
the instructions included with the upgrade. Virus
software is upgraded most frequently, with the
discovery of new viruses that are out there.
When you work with packaged software, you will
be concerned with what it does, how it does it, and how
you are to interact with it. For each different type of
application package, you will be confronted with anew
vocabulary. For example, the terms used with word
processing come primarily from the office/clerical
End users, especially first time users and
noncomputer users, will need your help to operate their
systems and their programs. They also need to know
how to care for and handle diskettes, manage disks and
files, whether you can control access by others, whether
you can protect the data, and whether the data is
environment (margins, tab sets, indenting, paragraphs,
and so on). The terms used with desktop publishing
come from the printing industry (fonts, type styles,
points, and soon). Spreadsheets bring us the vocabulary
of an accountant or bookkeeper (worksheets, rows,
columns, data cells). Database terminology may look
the most familiar to you, because many of the terms
come from data processing (files, records, fields, keys,
and indexes). First, we will look at the commonalities,
then at the specifics of several different types of
software packages—word processing, spreadsheet,
database, desktop publishing, and utilities.
Learning About Software
The first thing you will learn is there is a lot to learn.
You will need to know what functions you can perform,
what keys activate what functions, and how to save the
work/files you create. If a tutorial or learning section
comes with the software, start with it. It will give you an
overview. Then begin by experimenting and practicing
on something you cannot hurt or destroy. Don’t start
with the master copy of a large database file. Instead,
create a few records in a test file and practice on it. Try
out each function, then try the functions in combination
with other functions. Even make mistakes on purpose
to see what happens. Did the software give you an error
message? Can you recover? Does the software provide
an undelete feature that lets you cancel what you just
did? How much protection from error is built into the
software? Does it give you a message such as: Do you
really want to delete this file? Or, does it just assume
when you hit the delete key you mean to? Most of the
better software packages have built-in safeguards to
protect us from ourselves. Recovery from operator/user
error is a very important feature of many software
Regardless of the type of software package you are
using on your computer, at a minimum, you will need to
know how to conduct the following seven general
Access and execute the packaged software from
the operating system.
Create a new file or retrieve a previously
created file on disk/diskette or tape.
Interacting with Software Packages
Save a file onto disk/diskette or tape.
Basically there are only a few ways to tell software
what to do. They are as follows:
Delete a file stored on disk/diskette or tape.
Direct commands— You enter words/
characters via the keyboard to tell the software
what to do. These words and/or characters are
predefined by the software to perform specific
Print a file.
Indicate to the packaged software that you want
to stop working on what you are currently doing
to do something on another file.
Menus— You select the function or command
you want performed from a list presented on the
display screen by the software.
Terminate your work via the packaged software
and return to the operating system.
NOTE: Each software package will have
specific ways you are to perform these
Function keys— You select the function key
(F1, F2, and so on) that is predefine to tell the
software what you want it to do. This enables
you to perform some of the more common
commands without going through menus and
with fewer keystrokes than required for direct
A major consideration for a person working with
packaged software is file management. You will need
to know how files are setup, coded, named, backed up,
and accessed. You will need to know who can access the
enable you to create, modify (insert, delete, rearrnge),
save, copy, and print documents (see figure 3-1). The
usual method of entering a document is to type it on a
keyboard. Another method is to use a scanner to read a
printed document and encode it into a digital file for
computer processing. You might also receive a
document that has been transmitted over a network or
phone system.
l Programs/macros— You execute routines (a
series of instructions/keystrokes) that have been
developed and stored previously.
Which of these methods you will use depends on
the design of the software; not all software includes all
methods. Some software gives you a choice, and you
can select the method you prefer. When learning, it is
usually easier to use a menu because all the choices are
presented. Once you have learned the software, you
may prefer direct commands because you do not have to
work your way through a series of menus to find the
function or command you want. Programs/macros are
most useful for repetitive tasks. They enable you to
enter the sequence of keystrokes (steps) or characters
you want to repeat. Once entered and stored, you can
execute the entire sequence with one or two
keystrokes—a real time saver.
Creating and Modifying Documents
To create a new document, you will start by telling
the system you want to create a document. In some
packages this is the default option—the option you get if
you do not specify something else. When you load and
execute the program, you are in the create mode and
simply start typing. The software will probably have a
number of defaults that can be set up for your
installation. For example, you can probably have
defaults set to 8 1/2-inch by 11-inch paper, with a 1 1/2inch margin at the top, a 1-inch margin at the bottom,
and 1/2-inch margins left and right. You may be able to
have tabs set as a default option for indenting
Becoming a Proficient User
You will also learn that software does not do
everything you want in the way you would like. The
more you work with a package, the more you will be
able to find ways around what you consider
deficiencies. You will also learn you can compensate
for these problems by writing and saving your own
routines, programs, or macros to perform some of the
more complex or awkward functions. Some packages
enable you to define your own function keys, change the
function of a key, or store routines as macro
instructions. These are all desirable features for the
more sophisticated users. This also means routines can
be developed by experienced, proficient users for use by
other users.
Regardless of how the original document is entered,
eventually, it ends up as a data file on some type of
secondary storage media that you can later access and
modify (add, change, or delete). To make changes, you
Do not hesitate to learn from others and do not limit
your study. Ask others how they are using a package.
What tricks have they learned and found useful? What
routines/macros have they designed to perform
recurring functions? Build on their knowledge and
share yours. You might even institute a users group. It
need not be formally organized-maybe during the
noon time meal once a month.
Let’s take a more in-depth look at some of the more
commonly used software packages—word processing,
spreadsheet, database management, and desktop
publishing software.
Word processing packages are readily available for
use in office environments on microcomputers. They
Figure 3-1.—Examples of word processing program features.
must retrieve the file into the computer’s memory. The
software displays the document on the screen. You then
make entries by moving the cursor to the places in the
document where you want to make changes. Two
modes of operation are used—typeover and insert. As
the words imply, if you are in typeover mode, you will
replace what is presently there. If you are in insert
mode, the material to the right of the cursor will move to
the right as you enter new material. These, along with
other features, are shown in figure 3-2. Take a few
minutes to study the figure.
l Delete key— To take out unwanted characters,
words, sentences, and so on.
l Backspace key— To erase words to the left of
the cursor one character at a time. (NOTE: In
some packages this key may be defined
differently. For example, it may backspace
without deleting.)
l Typeover mode— To replace text by typing over
l W o r d w r a p — As you enter text, words
automatically move to the next line when the
right margin is reached. You do not have to press
the return key at the end of each line as you do on
a typewriter.
The basic features you will use are as follows:
l Cursor movement keys— Move the cursor up,
down, right, left, to top/bottom of document, to
next/previous page/screen; search to find a
character string or function code in the
l Cut and paste function— Allows you to move
material from one place in a document to
l Insert mode— To add letters/characters, words,
sentences, and so on.
l Function keys— To underline, center, tab,
indent; put text in bold; use subscripts/
superscripts. You can put text in columns; add
headers, footers, footnotes, page numbers, date,
and so on.
Special Features
Many word processing programs include
dictionaries and a thesaurus. These enable you to
check for correct spelling and to look for synonyms.
Some of the dictionary routines even provide a list of
correctly spelled words you might have meant. In this
case, you can correct a mispelled (or is it misspelled)
word by selecting the correctly spelled word from the
list on the display screen. The same is true of the
thesaurus, the software lists synonyms on the screen.
You select the one you want, and it replaces the original
word with the selected synonym.
Some word processing programs have automatic
paragraph numbering and outlining features. Once
you have created the outline or document, you can
delete or add entries, and the software will
automatically renumber/reletter the outline or
paragraphs in the document.
Some word processing programs have indexing
capabilities. You can tell the software which
words/terms are to be included in an index. The
software will then automatically create the index in
alphabetical order, with the appropriate page numbers.
Figure 3-2.—Examples of basic features found in word
processing packages.
Some enable you to create a table of contents or other
types of lists.
Simply defined, a spreadsheet electronically
duplicates an accountant’s or bookkeeper’s tools, which
normally consist of a ledger pad, a pencil (with an
eraser), and a calculator. When using spreadsheet
software, you enter and change data (figures of various
types) by typing on a keyboard rather than writing with
a pencil. You are able to view your figures on the
computer’s monitor rather than having to read a ledger
pad. The data is presented as it would appear on paper,
in rows and columns. Figure 3-3 is an example. Many
everyday tasks can be managed with spreadsheet
software. The computer can perform a variety of
mathematical calculations—from simple addition,
subtraction, multiplication, and division to
trigonometry, and statistical and business calculations.
Some word processing programs even include
some of the features of a spreadsheet package. While
they may not be as easy to use or as sophisticated, you
can define columns and rows and perform some
arithmetic functions. For example, you could total a
column or calculate total cost of an order by having the
software multiply the number of items by unit cost, and
put the result in another column.
Some word processing programs enable you to set
up records with defined fields. For example, you could
set up a file of records with names and addresses. Let’s
say your organization sends a memo each month to the
same list of organizations. Using a feature of the word
processing program, you could create one letter and
have the names and addresses inserted in (merged with)
the letter automatically in the proper places. This is the
same feature the sweepstakes companies use to insert
your name throughout their letters to you to personalize
them. This is sometimes called the mail merge function.
It is unlike the merge function we think of in data
processing in which the records in two or more like files
are sorted in the same sequence by keys and then
merged together into a single file. In mail merge, the
variable information (name, address, and so on) is
inserted in predefined places in a document and the
document is printed.
Understanding Spreadsheets
Before you can understand how a spreadsheet
program works, you must first have an understanding of
what the terms record, column, and data cell mean.
. Record— A record is represented by a line (row)
of data items of information on a spreadsheet.
This is the horizontal component of a
spreadsheet. Normally, a record contains
information about one particular item or topic,
for example, a person or a piece of equipment.
Spreadsheet rows are usually identified by
numbers (1, 2, 3, and so on).
Some word processing programs include many of
the features of desktop publishing. You can view a
finished document on the screen as it will appear on
paper—WYSIWYG (what you see is what you get).
You can scan art and insert it in the document. You can
use a variety of type styles and sizes (fonts) if your
printer can handle them.
Capabilities are continually being added and
combined. You might have several electronic office
tools all rolled up into one package—word processing
with mail merge, database with report capability,
spreadsheet with charting capability, and a
communications package. How is that for an integrated
software package! You will be able to use each tool as a
separate entity, or you can integrate them together to
produce sophisticated reports by combining text,
graphics, and images in relatively complex
multicolumn layouts. These packages will also include
a graphical user interface (GUI) or lists of options
(menus) presented on the screen, rather than having you
memorize numerous computer commands to get the
personal computer (PC) to do what you want.
Figure 3-3.—Example of a spreadsheet/worksheet.
some of the more common ways you can expect to
interact with a spreadsheet software package:
l Column— A column is the vertical component
of a spreadsheet. A record (or row) can have
many associated columns, such as base pay,
FICA, state tax, federal tax, and so on. Each
column contains one type of information and is
normally labeled to identify the type it contains,
such as base pay. The columns are usually
identified by letters (A, B, C, D, and so on).
l Cursor movement (or arrow) keys— You can
move the cursor one cell at a time in one of four
directions—up, down, left, or right. Other keys
such as PgUp and PgDn move the cursor up or
down one full page; still others, when used in
conjunction with other keys, move the entire
worksheet in a specific direction.
l Data cell— A data cell contains one piece of
information associated with a particular record.
Thus, a record/row that contains seven pieces of
information will have—you guessed it—seven
data cells. A data cell is symbolically identified
by using some type of common
notation-usually column, row. Therefore, if
you have a spreadsheet with 20 records, each
with 7 columns of information, the rows will be
numbered from 1 through 20, and the 7 columns
will be identified by the letters A through G. In
this way, the fourth column, sixth row of the
spreadsheet will be data cell D6, which, in figure
3-3, contains the value 2156.10.
l Function keys— You can use F1, F2, F3, and so
on, to display HELP screens, edit entries, display
range names, enter absolute formulas, move
back and forth between screens or windows,
perform range and global recalculations, and so
l Spreadsheet commands— You can use
commands to tell the software what to do.
Features of Spreadsheet Software
The entire collection of data cells is often referred to
as a matrix or an array. When entering data, it is not
necessary to enter it in alphabetical or numerical order;
the software package will normally arrange the data in
whatever sequence you desire.
Spreadsheet software packages normally include
ways to do the following things:
In looking at figure 3-3, you will notice each
individual has only one record, and each record/row
contains seven columns (or data cells) of information.
There could have just as easily been 20, 50, or 75
columns of information per record. The number of data
cells is limited only by the parameters of the spreadsheet
software and by the amount of available RAM. To give
you some idea of a spreadsheet’s size, the worksheet you
see in figure 3-3 might be only a small portion of the
entire worksheet—the amount that can be displayed at
one time. Although there appear to be only 20 rows and
7 columns of information, depending upon the software
package you are using, it could conceivably contain up
to as many as 8,192 rows and 256 columns of
information totaling more than 2 million data cells. A
spreadsheet of this size would be equivalent to a piece of
paper approximately 21 feet wide by 130 feet long. Try
spreading that out on a table!
l Enter formulas (to perform calculations,
analyses, comparisons, and projections).
l Enter labels (non-numeric data).
l Enter values (numeric data).
l Insert and delete columns and rows.
l Copy and move ranges of data cells/records
from one area of a worksheet to another.
l Erase part or all of a worksheet.
l Change the way values are represented on part
or all of a worksheet.
l Split the viewing screen to allow you to view
two parts of a worksheet simultaneously.
l Save, retrieve, rename, erase, and copy files.
l Print a worksheet.
Figure 3-4 is an example of a printed spreadsheet
showing the labels and titles, along with the values you
entered (shown in italics), and the values calculated by
the computer (shown in bold). Notice all the totals and
subtotals were calculated by the computer. By using
spreadsheet software, you need only enter a new price
Interacting with Spreadsheet Software
Like other software packages, you have cursor
movement keys, function keys, and commands to tell
the software what to do. The following list contains
security number (SSN), division, and any NECs the
individual currently holds.
Once you have defined the record, you then proceed
to establish fields for each of the data elements. In this
example the fields are name, rate, SSN, division, and
NECs. If you assume each individual can have a
maximum of four NECs, you would have a database
containing eight fields, as shown in figure 3-5. You now
proceed to create the database by establishing the fields,
specifying their size and the type of information
(numeric, alphanumeric, or logical) they can contain.
Then, you enter the information for each individual into
the appropriate fields. Once it is created, you can
arrange the database in some logical order (by NAME,
SSN, and so on). The database is normally stored on
some type of secondary storage medium (usually disk),
where the information is simply held until you need it.
Figure 3-4.—Examp1e of a printed spreadsheet.
Now, suppose you wanted a list of the E-5 and E-6
Storekeepers in the supply department with an NEC of
1234. Under a manual system, you would have to open
and search through each individual’s file folder-there
could be hundreds! You would look at various entries;
first, for rate (or the rate field in your database file);
then, in order to see if this person is assigned to the
supply department (the division field). You would then
check to see if this person has an NEC of 1234 (the four
NEC fields). Finally, you would have a stack of folders
for all E-5 and E-6 Storekeepers who are assigned to the
supply department and who have an NEC of 1234. You
could then list the names from the file folders (the
records) selected.
when the price changes and direct the computer to
recalculate the totals/subtotals.
Many of the available spreadsheet software
packages will interact directly with other programs such
as database and word processing applications. Some
spreadsheet packages integrate (or combine) several
programs into one, such as a spreadsheet program, a
graphics program, and a database management
Depending upon the number of folders you have to
look through, the entire evolution could take hours to
complete. On the other hand, you could use one of the
many database packages available to obtain the same
answer. The database application program, by knowing
the fields in each record and the content of each field,
can easily search for this information in a matter of
seconds. You simply specify the selection criteria and
the report format; the software does the rest—searches
Before we get too involved in database packages,
let us first define what a database is. The term database
conjures up different images for different people.
However, the concept is about as nontechnical and easy
to envision as a filing cabinet full of file folders. The
filing cabinet and its contents are the database. The
ability to retrieve the data and calculate statistics
quickly and easily without regard to which folder or
drawer contains the information makes the database
system much more powerful than a comparable filing
cabinet system.
Let’s consider a simple database, one which
contains information about all enlisted personnel at
your command in paygrades El through E6, including
their NECs. First, you must establish a record in the
database for each individual. Conceptually, you can
think of it as a file folder containing information on one
particular individual. You have one file folder, or
record, for each individual in your database. In this
case, we want to know the individual’s name, rate, social
Figure 3-5.—Example of a database record.
the database for the records that meet the criteria (SKI
or SK2, Supply Department, and NEC 1234). The
computer then displays or prints the requested
information in the format specified. See figure 3-6. You
do this through the query and report features of the
database package. Doesn’t that beat manually searching
through a drawer full of folders, which could take
Field— A field consists of one unit of
information. A field is also referred to as a data
item or a data element. It maybe alphabetic, like
your name (John or Jane Doe); numeric, like
your ZIP Code (01234); alphanumeric, like your
post office box or street address (P. O. Box 669 or
1234 Main St.); or logical (true/false), like on
leave (true-on leave, false-not on leave).
A database is nothing more than a collection of
data—many file folders or individual records
containing several fields or data elements. The database
is organized to allow you to retrieve, update, and have
ready access to various information that can be
formatted and printed as you desire. The database itself
doesn’t do anything; it just holds information.
Pointer— A pointer is a data item in one record
that identifies the storage location of another
logically related record.
Index— An index enables you to access records
in a database (also referred to as database file or
file) in the order of the index regardless of the
physical sequence of the records in the database.
You can think of indexing as sorting without
having to sort. The index itself is a file. It
contains a duplicate of the key field (or fields)
such as account number, or name and security
number, and a pointer to the actual disk record
identified with this key in another permanent
disk file. For example, if there are 5,000 records
in your database, and the key field happens to be
SSN, then the index would also contain 5,000
entries with each entry having an SSN. It is also
possible for you to have one or more secondary
indexes that contain other various secondary key
Understanding Database Software
To understand how a database program works, you
first need to have an understanding of certain terms.
Some of the terms you are already familiar with,
whereas others you may not be. These include
database, record, field, pointer, index, primary key,
and secondary key. They are defined as follows:
. Database— A database holds information that is
related to a specific type of application-payroll,
personnel, supply inventory, and so on. In this
context, the term database is often considered
synonymous with file. This is especially true
when dealing with database files.
Primary key— The primary key in a database
consists of a unique identifier for a particular
record and should only point to a single record in
the database being indexed.
l Record— A record consists of a group of related
fields, all pertaining to the same subject: a
person, a thing, or an event.
Secondary key— Data are normally arranged
within a database in some type - of order,
depending upon the contents of one or more
fields. Secondary keys allow you to access the
database in different ways. For example, your
database might be arranged in the order the
records were entered. You can then set up a
secondary index (or key) by the name field, or by
the social security number field. You may
specify any number of secondary keys. You
might index by more than one field. For
example, you could index by last name within
rate, as shown in figure 3-6.
Database Organization Methods/Structures
Databases can be list, hierarchical, network, or
relational in structure. The major advantage of a
Figure 3-6.—Example of a database report.
database is it permits the maintenance of a related set of
files or tables that can provide information to several
different users. So how do these database structures
differ? you might ask. That’s a good question. Read on
and find out.
LIST DATABASES.— List databases link records
together through the use of pointers. The pointer is a
data element in one record (normally the master record)
that points to the actual disk location of another
logically related record, as illustrated in figure 3-7.
databases consist of elements that act in a superiorsubordinate or parent-child relationship. What this
means is that one element is linked to another element in
the database. The superior element points to one or
more subordinate elements. There can also be a
subordinate of a subordinate, which will enable many
hundreds of elements to be connected. See figure 3-8.
NETWORK DATABASES.— Network databases
are very similar to hierarchical databases except that an
element can have one or more superiors. Network
structure permits the connection of the nodes
multidirectionally. Each node may have several owners
(or elements) and may own any number of other data
elements on the network (see figure 3-9). The database
management software permits the extraction of needed
information from such a structure to begin with any
record in the file. Although network databases are more
flexible than hierarchical databases, they still have
limitations. The networking scheme must be defined
when the database is initially created, and information
retrieval is based solely on the predefined scheme.
Figure 3-7.—Example of a list database structure.
Figure 3-9.—Example of a network database structure.
Figure 3-8.—Example of a hierarchical database structure.
databases have many advantages over network and
hierarchical databases. They consist of one or more
tables in which data are stored in the form of rows and
columns. The main advantage is that relationships
between the data can be established whenever you (the
user) request information. For example, relation tables
could be used to link a person with his/her NECs, duty
assignments, and any special qualifications, as shown in
figure 3-10. Many other relations are, of course,
possible. Any relational database package normally
uses an index of some sort for faster access to the data.
Relational structures are a very popular database
structuring approach for both mainframe and
microcomputer database packages.
l Create and run forms and reports, design and
print labels.
l Query the database for information.
l Create and run/execute applications programs.
l Import and export files.
You can use function keys F1, F2, and so on, to
provide help screens, to display lists of items, to design
database files, queries, reports, forms, and labels; to add
fields to a layout, to move or copy selected data, to
enlarge/shrink fields or condition boxes, to print a quick
report, to access menus for the current screen, to access
macros, and so on.
Some database packages provide you with some
type of control screen like the one shown in figure 3-11.
Using a control screen allows you to access a number of
features. This particular control screen has six panels,
each corresponding to a different type of operation on
your database. Displayed across the top left-hand
corner of the control screen you see three main
menus— Catalog, Tools, and Exit. Catalog provides
you with options for managing catalogs and the files
contained in them. A catalog is a file in itself that
contains the names of related files. Tools provide you
with a variety of utilities for accessing the disk
operating system (DOS), for importing and exporting
files, and for setting program parameters. Exit enables
you to leave the control screen and go back to the disk
operating system.
Using Database Software
Some of the more common operations you can
expect to perform when using a database software
package are as follows:
. Create databases.
. Insert, update, and delete data in a database.
Figure 3-11.—Typical control screen used with database
Figure 3-10.—Example of a relational database structure.
Most database packages provide you with some
type of query language that allows you to query a
database to obtain answers about the contents of the
database, insert new data, update information in various
tables, and create views. By using various commands
and control statements, you can perform arithmetic,
logical, and comparison operations on the data you have
Desktop Publishing Composition
Composition includes defining the sizes and styles
of type to be used, the amount of space to allow between
horizontal letters and vertical lines, and coding the text
(copy) to meet these standards and definitions.
You can enter and edit text directly or you can input
text created using a word processing program.
Documents created in word processing programs can be
imported into the DTP software. Once they are
imported, you can manipulate the text (copy) any way
you want to satisfy your particular publication needs.
The following are features and terms you need to
become familiar with:
Desktop publishing (DTP) packages are used
primarily for designing and publishing professional
looking documents. They offer you a wide variety of
publishing applications. Typical applications include
newsletters, advertisements, letterheads, reports,
presentations, catalogs, books (such as this TRAMAN),
brochures, or flyers, forms, business cards, contracts,
magazines, and overhead displays. Again, you will see
and hear new terms when you begin working with
desktop publishing software. These terms come
primarily from the printing/publishing industry.
l Type styles and sizes— Type is classified
according to its style of letter and size. You can
choose a variety of type styles (typefaces) and
sizes to create impressive forms, letterheads,
brochures, flyers, and so on. Examples of
Courier and Roman-WP are shown in Table 3-1.
Notice each is in a different size. Printers’
measurements are based on the point system.
The point is approximately 1/72 of an inch.
When you hear someone say 8-point type, that
simply means that the body of the type measures
1/9 of an inch from top to bottom; 12-point type
measures 1/16 of an inch, and so on. The
typeface itself is seldom as large as the body,
because a small shoulder or ledge is left below
the letter on most type. Type sizes range from 3to 120-point. You will also see the term font used
in connection with desktop publishing and word
processing. A font is a collection of characters of
unified design—the typeface and point size are
needed to specify a font. However, the term font
is often used interchangeably with typeface.
The features of desktop publishing can be
categorized as composition, layout, and graphics.
Let’s take a look at each area.
Table 3-1.—Table of Type Styles in Several Fonts
Automatic page numbering— You can have
the software automatically number the pages.
. Letterspacing and leading— You can adjust
space both horizontally and vertically.
Letterspacing refers to the addition of small
spaces between l|e|t|t|e|r|s within a word.
Leading refers to the space added between lines
of material.
Headers and footers— You can also have
appropriate headers (titles) at the top of every
page and footers at the bottom of every page.
Headers or footers can usually include page
You can create an index or table of contents by
marking special words for an index or use headings and
sideheadings to make a table of contents.
Desktop Publishing Graphics
Desktop publishing packages have the capability to
scan or import illustrations/graphics either from
hardcopy or from digital data. The following are
graphics features you can expect to find in DTP
Desktop Publishing Layout
Layout involves arranging the text and graphics on
the page. The text may flow from column to column on
multicolumn documents like the newspaper. You may
have to move text from one part of a document to
another using the electronic pasting features. You can
incorporate illustrations on a page with text. Borders
may be drawn around text or illustrations. Illustrations
may be sized (made smaller or larger), and additional
letter spacing and leading may be added to create a full
page. To lay out a pleasing document requires
experience and practice as well as a good eye for
balance. You will find the following features in most
desktop publishing packages:
l Graphic images— You can add images, borders,
lines, arrows, and so on, of various sizes to the
l Shrink/expand and edit images— You can
reduce or enlarge images to fit in a desired space.
If necessary, the images can be altered or edited.
l Accept images from scanners or other draw
programs— You can import images from a
scanner or digitizer. These images can be in
either text or graphic form. Images can also be
imported from either a paint or draw-type
graphics package.
l Lay out pages and edit page layouts— You can
lay out pages electronically, rather than having to
cut and paste using scissors and glue.
l Layered output for color printing— You can
create camera-ready copy for color separation
work when an outside printing process is
required. Color work is done by creating up to as
many as four film negatives (one for each of the
primary colors—red, yellow, and blue) plus
black. Each negative is used to create a separate
printing plate for each color. Then, as the colors
are overprinted, the color of the original
photograph is reproduced.
l Incorporate text and graphics— Your text and
graphics can be electronically merged together
in the layout.
l Multiple columns, column widths, and
heights— The software automatically formats
multiple columns on continued pages. You
specify how many columns are to be on a page
and the amount of gutter space desired. Gutter
space is the amount of space between columns.
l Vertical/horizontal printing— Material can be
printed either vertically or horizontally on a
sheet of paper.
Hardware Requirements
Unlike the software packages previously discussed,
desktop publishing packages (and graphics software
packages) require a considerable amount of resources.
To give you a better idea of what we are talking about,
the following are hardware requirements:
l Fit copy to page— You can fit the copy to a page
either by reducing the type size, increasing or
decreasing borders or margins, and any other
number of creative ways you can come up
with-changing the size of an illustration,
cutting off (cropping) an illustration, or even
rewording some of the text.
. Microprocessor—At a minimum, you will need
a 486 sixteen-bit microprocessor or equivalent.
A Pentium or 586 (or equivalent) is even better.
by applications or operating system software. For the
most part, utilities are meant to work in conjunction
with your existing software.
Do not plan on using PCs based on 286 and 386
microprocessors. These machines simply do not
have enough computing power to handle DTP
chores efflciently.
In the past, an individual had to be a technical expert
when it came to setting up the necessary control
parameters for a particular utility program (a sort,
merge, selective print, and so on). Quite often, they
were complicated to run. Some of these utilities were
stand-alone programs occupying a niche not filled by
applications programs. The traditional mainframe
utility programs, such as sort, merge, and print, have
given way to desktop organizers and file managers that
are now geared for individual use on a personal
computer. Today, most microcomputer users initiate a
wide variety of software utilities and are not even aware
they are doing so. Some of the more popular utilities
have been incorporated into the disk operating system
as well as applications programs as commands.
Monitor— You will need a high-resolution 19inch monitor. When doing desktop publishing
and design work, laying out pages on most
standard 12-inch and 13-inch screens can be
tiring and difficult. The monitor and associated
graphics card should be at the IBM-standard
video-graphics array (VGA) level or better.
Secondary storage— Large hard disks are
essential for DTP work. Desktop publishing
files tend to get very large, and you will soon
accumulate many active files on the computer’s
hard disk. A minimum of 500 megabytes of hard
disk capacity is recommended. Hard drives with
850 megabytes to 2 gigabytes are even better.
DOS includes such utilities as COPY, SORT,
files), DIR (to list files in directories), RENAME (to
rename files), CLS (to clear your monitor’s screen), and
many, many more. Utilities such as spell checkers,
dictionaries, thesauruses, and grammar checkers are
often included in word processing packages. Many
applications programs include keyboard enhancing
programs that allow you to store frequently used words
and sentences you can then access with either a single
keystroke or combination of a few keystrokes (also
known as hot keys). Then, there are mouse utilities that
allow you to program the right and middle mouse
buttons for particular tasks.
Mouse or trackball— You will also need a
mouse or trackball pointing device to move the
cursor position on the monitor screen.
Printer— Although the dot matrix printer is
inexpensive and capable of printing graphics and
letter quality text, it is insufficient for many DTP
applications. A laser printer is the better choice
when it comes to preparing quality text and
Scanner— With desktop publishing systems,
you will naturally want a desktop scanner to
capture photographs, art work, clippings, and
other forms of art work.
While utility programs are getting easier for us to
use, selecting the best one to accomplish a particular
task can be somewhat difficult. If you look around to
see what utilities are available, you will find there are
thousands of various types on the market to choose
from. To introduce you to the types, we have organized
the various utility software/programs into eight
categories: keyboard enhancement, desktop organizer,
backup, file management, file maintenance, DOS shell,
printer, and virus utilities.
More and more DTP functions are being added to
word processing packages. For some applications, this
will eliminate the need for separate DTP packages.
However, you will still need a scanner, a mouse, and a
compatible laser printer.
Software utilities further enhance your computer’s
capabilities and make it run more efficiently, whether it
be a mainframe, mini, or micro. Once a computer user
like yourself becomes familiar with the system and
applications software you are working with, you want
the system to do more and do it faster and more
efficiently. Utilities can satisfy some of this need for
more computer power, overall performance, internal
security, file and data management, and backup
capabilities. Utilities strive to fill some of the voids left
Keyboard Enhancement Utilities
Keyboard enhancers, as the name implies, enhance
the function of the PC keyboard. These programs
(which are usually RAM resident programs) translate a
single keystroke into user-defined macro commands.
A macro consists of one instruction that represents
many instructions. For example, Ctrl-Alt-C keystrokes
file attributes. In short, file management utilities
provide you with a convenient way to keep hard-disk
directories, subdirectories, and the files themselves
organized and under control.
could be simplified as the Esc key with a user-defined
macro. Any string of keystrokes or characters can be
stored as a macro. More importantly, once you have
defined the macro, it can be stored as a file for use with
different applications. In short, by shortening
commands and character strings, keystroke repetition is
greatly reduced.
File Maintenance Utilities
File maintenance utilities include file recovery
utilities (including backup and restore) and programs
that manipulate files, such as data compression and file
security programs. File recovery utilities are designed
to identify, diagnose, and repair every form of data and
low-level format damage on standard DOS hard disks.
One of the most critical areas of file maintenance is file
recovery. If you should accidentally erase a file, it can
easily be recovered (unerased) by using a recovery
Desktop Organizer Utilities
Desktop organizers consist of programs that
emulate such things as calculators, notepads, phone
directories, calendars, and appointment books. Most of
these utilities are RAM resident. This means they can be
accessed from within other applications programs. For
example, you can call up the calculator utility while you
are currently working in a word processing application.
An image of a calculator will “pop-up” in a small
window on your monitor’s screen. You then perform the
necessary calculations, and return to the word
processing application. Some desktop organizers allow
you to take the resulting calculation and place it directly
into the word processing document you are working on.
This is refereed to as “cut and paste.” Most programs
included in desktop organizers also operate in this popup mode.
Compression utilities save disk space by reducing
file size by 40 to 60 percent. Encryption utilities are
designed for file security. Using one of several
encryption algorithms, these utilities will encode a file
so that it is readable only by reversing the encryption
process. Other utilities are designed to “hide” files from
the operating system; that is, the file “disappears” from
the operating system and is only accessible with a
password. Still others are designed to control access to
files, programs, and communications devices.
Backup Utilities
DOS Shells
As computer specialists, we should all be familiar
with backup utilities. Disk backup utilities provide us a
cost effective way to backup a hard disk. Advanced
features, such as automatic backup (backups taken at
predescribed intervals), file compression (which allows
more data to be placed on a diskette), and automatic disk
formatting, make disk backup utilities a good
alternative to the backup utilities supplied with most
operating systems. Backup utilities also allow you to
save your files to tape, or even to another hard disk.
These utilities, called DOS shells, help translate
DOS codes into English words, phrases, and diagrams.
They act as a liaison between you and the operating
system. They display disk and file information, adding
commands not available in DOS and tend to simplify
the execution of standard file management commands,
such as DELETE, COPY, and PRINT.
Printer Utilities
File Management Utilities
Printer utilities provide software support for the
enhanced fonts and graphics found in many printers.
They also provide such features as menu control for
printer functions, print spooling, and printing
horizontally. Printer utilities allow you to use a printer
that your applications software may not support. They
also allow you to make better use of your standard
As the capacities of hard disks increase, so does the
need for file management utilities. Try keeping track of
the files on a 2Gb hard disk without any type of file
management utility. It is next to impossible. Adding to
the problem can be a maze of subdirectories—
originally set up to keep order—that can easily hide a
file or two. File management utilities help you avoid
these problems by manipulating files and directories.
They perform tasks such as searching for files, deleting
files, tagging files (to allow for file manipulation on
groups of unrelated files), relocating files, and setting
Virus Utilities
Virus utilities are designed to keep out the
malicious logic (unfriendly viruses) that attack
computer system software. This type of software is
designed to prevent both known and unknown viruses
from invading a system, and to detect and remove those
already present. Virus detection software (IBMAV) is
available free to all DON activities from Naval
Command, Control and Ocean Surveillance Center InService Engineering, East Coast Division
(NISEEAST), in Charleston, South Carolina. For more
information concerning virus software, refer to chapter
2 in this module.
To translate user requirements into technical terms,
the first skill you will need is the ability to communicate
with the users. Usually, the users know what they want
and need, but they do not always know how to phrase it
and put it into a logical process. That is where you, the
computer specialist, come into play. As
communications specialists, we have to be able to
translate their ideas into a logical process. One effective
method we can use is pseudocode because the code can
be easily read and understood by both users and
communications specialists (figure 3-12). After we
determine the process and document it in pseudocode,
we take the pseudocode to the users for their review to
make sure we have covered all of their needs. After
talking with the users, we make any necessary changes,
then go back to the users again. As the programmer, it is
your responsibility to determine the necessity and
feasibility of the user’s requirements to avoid
unnecessary or even impossible programming. We
continue this process until the users have no more
changes and approve the pseudocode. The approval is
required before moving on to the development of the
program requirements.
Utilities of the Future
What can you expect to see in the fuure? More and
more, you will see vendors combining several utilities
into one package. These packages will be difficult to
categorize because they will work with operating
systems, application programs, and peripherals. For
example, a file maintenance utility may combine
several commonly used programs such as disk
diagnostic and recovery utilities, a DOS shell, hard-disk
backup, a desktop manager, and a disk optimizer (a
compression utility).
So, how do you go about staying on top of the latest
and greatest utility packages available? That’s easy !
You can learn about utility programs by reading trade
magazines and software reviews. Let the experts do the
leg-work of evaluation for you. There are so many
utilities available on the market that it would be
impossible for you to do a good job of evaluating them
on your own. Vendors of application software and local
computer clubs are other good sources of information.
Determine System Software Requirements
When we start to determine the system software
requirements, we look at the pseudocode and the user’s
requested end product(s) to determine whether a
commercial software package is available to
accomplish the job or if we will need to develop an inhouse program.
Figure 3-12.—Pseudocode example.
find the hardware needed is not being used where it is
located and you can move it to meet the new
requirements. If the hardware is not available at the
facility, begin the acquisition process. This process is
the same as for software, except, in most cases, the
requirements will have to go out on bids to several
companies. With this process, it may take a long time to
receive the hardware. You should plan accordingly.
To determine whether the job can be done with a
commercial software package, you need to be aware of
the different software packages available and their
capabilities and features. If it appears you can use a
commercial software package and your AIS facility
does not have it, start looking at the different government contracts in effect to locate the particular software
package you are interested in. If the software is not
available on contract, you will have to look for outside
sources. Once you locate the software package and
obtain approval for purchase, you can start the process
of filling out the paperwork to order the software.
Calculate Memory Requirements
When translating user requirements into an
application, there are several things to keep in mind. We
have covered the system software and hardware
requirements; now, we turn our attention to the memory
requirements. Calculate the memory requirements
carefully; it will do no one any good to create a program
that can not be run due to memory constraints of the
system. Factors to be combined when calculating
memory requirements are:
If you determine no commercial software is
available to accomplish the user’s request, you need to
look at the expertise available in your AIS facility and
what programming software is available at your facility
to accomplish the job. Powerful software is available to
mike the programmer’s work easier. This software falls
into one or more of the following categories:
. the operating system,
Query languages. Allow records to be printed
or displayed in a specified format.
l the program, and
. the data to be input.
Database languages. Allow records to be added
or retrieved and manipulated following set
By taking into consideration the memory requirements
of each of these factors, there should be no problems (as
far as memory goes) with running the programs.
Report generators. Allow reports to be created
from retrieved data records.
Application generators. Allow the use of prewritten modules in creating a program.
Once you develop the pseudocode and identify the
software and hardware requirements, you can begin
developing the I/O and program specifications. This is
also a good time to determine what type of file organization method will best suit the application. The I/O
specifications will require the users interaction to
further detail what they need as input data and output
material. They are your primary source for this information. To prepare the program specifications, you will
use the pseudocode and design the program to match.
Also, look at the memory and storage requirements for
the program. You may have to adjust the hardware
requirements to match the program specifications. Be
sure you are not going to overload the computer system.
High-level languages. Allow the programmer
to create a program from scratch.
Generalized software. Directs certain internal
computer functions.
Determine System Hardware Requirements
Once you determine the source of the program,
whether a commercial or an in-house program, you
need to look at what type of hardware will be required.
Commercial software will have the hardware
requirements stated in the paperwork. The users may
have certain hardware requirements dictated to them
that will have to be met. For example, a laser printer, a
specific type of floppy drive, or a CD-ROM drive may
be required. For in-house programs, it may be more
difficult to determine the hardware needed until the
program specifications are complete.
File Organization
File organization is the technique of physically
arranging the records of a file on a storage media. When
the programmer creates a subschema, a determination
must be made on how the file will be accessed by the
program. The three file organizations methods used
are: sequential, indexed sequential, and direct.
When additional hardware is required, you should
first determine if it is available at the facility. You may
handle several files with hierarchical or relational
structures, perform functions in an online mode, and
have sophisticated query and report writing
l Sequential file organization. In sequential file
organization, the records are in the same order as they
were written to the file.
l Indexed sequential file organization. I n
indexed sequential file organization, the records are
stored in sequence according to a primary key and an
index is created to allow random access of the file. This
type of organization also allows the file to be accessed
sequentially. Indexed sequential is the most commonly
used type of file organization.
DBMSs are being used on a wide variety of
computers in the Navy. Because of this, no one DBMS
by any single manufacturers discussed in this chapter.
Most of the problems with DBMSs in Navy
computer systems are the same as in the civilian
workplace. A few of these problem areas are noted
l Direct file organization. In direct file
organization, the records are stored and retrieved using
a relative record number, which gives the position of the
record in the file. This type of organization also allows
the file to be accessed sequentially.
. Users do not want to share their data with others
in the database.
. Privacy and safeguarding of proprietary
information are not sufficient.
A database management system (DBMS) is a
software package that provides an integrated source of
data for multiple users, while presenting different views
of that data to different users. It can be characterized as
generalized software that provides a single flexible
facility for accommodating different data files and
operations, while demanding less programming effort
than conventional programming languages. It features
easy access to the data; it facilitates the storage and
maintenance of large volumes of data; and, most
importantly, it provides the capability for sharing the
data resources among different types of users.
. Different views of data are needed by technical
and nontechnical DBMS users.
. Data representation is inadequate.
. Data structures are not tailored to individual user
The wide use of DBMSs in the Navy indicates that
all or most future operating systems will be oriented
primarily toward DBMS. Slowly, but surely, the DBMS
problems in the preceding list are being eliminated
through better and more sophisticated software,
coupled with advanced training of users on such
software usage.
Database management systems range from
elementary systems with single record structures,
providing rudimentary report formatting facilities, to
very elaborate systems. The very elaborate systems
Take a look at the changes that have been made
from the conventional system file structure to the
database management system structure. As shown in
figure 3-13, a conventional system is many application
Figure 3-13.—A conventional system.
predecessor, the file management system. DBMS
software evolved from many different software
improvements, from many different manufacturers.
None of the many DBMSs function exactly alike.
Regardless of the manufacturer’s software installed at a
particular AIS facility, a basic DBMS can be
conceptually depicted as shown in figure 3-14. Take a
few minutes to study the figure and refer to it as you
study this section. You need to understand the concepts
before we pictorially depict a DBMS execution event.
The concepts include schemas, subschemas, data
definition language (DDL), and data manipulation
language (DML).
programs or systems using different databases and files.
These databases and files are systems that are either
online or offline; at any rate, they must be online at
execution time. Under a conventional system, when the
same data was needed in SYSTEM A and in SYSTEM
B, it was usually duplicated. This redundancy of data is
not acceptable to the AIS community. The following
problems are just a few of those that exist when
redundancy of data is required:
l Excess storage is required.
l An excessive number of personnel is required to
handle and manipulate the data.
l A greater chance of error is possible when
updating all the common data in different
databases and files.
l Excessive funds are expended for report
production for management.
A schema is a complete description of a database,
and consists of data definition language (DDL) entries.
It includes the names and descriptions of all of the areas,
set types, record types, and associated data items and
data aggregates as they exist in the database and are
known to the DBMS. In other words, it is the overall
logical database description or framework into which
values of data items can be fitted. A schema can be
viewed like the bins in a storage house holding supplies.
The schema will not change, but the data values will.
l Excessive CPU time is expended when
collecting data for reporting.
l Data integrity is harder to maintain because of
the greater chance of error.
To overcome these problems, many Navy AIS
facility are using a DBMS. This has produced a better
record in operations and productivity than its
Figure 3-14.—A database management system (DBMS).
collection may consist of data items, vectors, and
repeating groups.
A subschema is the applications programmer’s view
of the data within the database pertinent to the specific
application. A subschema has access to those areas, set
types, record types, data items, and data aggregates of
interest in the pertinent application to which it was
designed. Naturally, a software system usually has
more than one programmer assigned and includes more
than one application. This means there are usually
many different subschemas for each schema.
The following are a few of the many reasons
subschemas are used:
l Subschemas provide different views of the data
to the user and the programmer, who do not need
to know all the data contained in the entire
l Subschemas enhance security factors and
prohibit data compromise.
l Subschemas aid the DBA while assuring data
Each data item included in the subschema will be
assigned a location in the user working area (UWA).
The UWA is conceptually a loading and unloading zone,
where all data provided by the DBMS in response to a
CALL for data is delivered. It is also where all data to be
picked up by the DBMS must be placed.
Schema Data Definition Language (DDL)
The schema data definition language (DDL) is used
for describing a database, which maybe shared by many
programs written in many languages. This description
is in terms of the names and characteristics of the data
items, data aggregates, records, areas, and sets included
in the database, and the relationships that exist and must
be maintained between occurrences of those elements
in the database.
l Record. A record is an occurrence of a named
collection of zero, one, or more data items or data
aggregates. This collection is specified in the schema
DDL by means of a record entry. Each record entry in
the schema for a database determines a type of record,
of which there may be an arbitrary number of record
occurrences (records) in the database. For example,
there would be one occurrence of a PAYROLLRECORD type of record for each employee. A
database key is a unique value that identifies a record in
the database to a run unit (program(s)). The value is
made available to the run unit when a record is selected
or stored and maybe used by the run unit to reselect the
same record.
. Set. A set is an occurrence of a named collection
of records. The collection is specified in the schema
DDL by means of a set entry. Each set entry in the
schema for a database determines a type of set, of which
there may be an arbitrary number of set occurrences
(sets) in the database. Each type of set specified in the
schema may have one type of record declared as its
owner type of record, and one or more types of records
declared as its member type of record. Each set
occurrence (set) must contain one occurrence of its
defined owner type of record and may contain an
arbitrary number of occurrences of each of its defined
member type of record types. For example, if a set
type QUALIFICATIONS was defined as having owner
record type EMPLOYEE and member record types
JOB and SKILL, each occurrence of set type
QUALIFICATIONS must contain one occurrence of
record type EMPLOYEE, and may contain an arbitrary
number of occurrences of record types JOB and SKILL.
l Area. An area is a named collection of records
that need not preserve owner/member relationships. An
area may contain occurrences of one or more record
types, and a record type may have occurrences in more
than one area. A particular record is assigned to a single
area and may not migrate between areas.
l Data item. A data item is an occurrence of the
smallest unit of named data. It is represented in a
database by a value.
l Database. A database consists of all the records,
sets, and areas that are controlled by a specific schema.
If a facility has multiple databases, there must be a
separate schema for each database. Furthermore, the
content of each database is assumed to be independent.
l Data aggregate. A data aggregate is an
occurrence of a named collection of data items within a
record. There are two kinds-vectors and repeating
groups. A vector is a one-dimensional sequence of data
items, all of which have identical characteristics. A
repeating group is a collection of data that occurs a
number of times within a record occurrence. The
l Program. A program is a set or group of
instructions in a host language such as COBOL or
program of a particular software system reading a
record. It is intended as a conceptual training aid for
instructional purposes only.
FORTRAN. For the purpose of this chapter, a run unit
is an execution of one or more programs.
Data Manipulation Languages (DMLs)
The numbered arrows in figure 3-15 trace a call for
data by application Program 1 of System A. (Calls for
data by other programs maybe handled concurrently by
the DBMS, but this is not depicted in the figure.) The
following events (numbered to correspond with figure
3-15) take place, depending on the software system in
use, when a program attempts to read a record:
A data manipulation language (DML) is a language
used to cause data to be transferred between a run unit
and the database. A DML is not a complete language by
itself. It is called a query language by some
manufacturers. It relies on a host language to provide a
framework for it and to provide the procedural
capabilities required to manipulate data.
DBMS Events
1. DML Program 1 of System A makes a call for
data from Database (A) to the DBMS.
To depict DBMS events, we selected the READ
function. The sequence depicted in figure 3-15
2. The DBMS analyzes the call and supplements
the arguments provided in the call itself with
information provided by the schema for Database (A),
and the subschema referenced by Program 1.
provides a conceptual example of an application
3. The DBMS obtains the subschema used for
System A and retrieves the description of the data in
4. The DBMS examines the database physical
description and keys the actual physical record to read.
5. On the basis of the call for its services and the
information obtained from the schema and subschema,
the DBMS requests physical I/O operations, as required
to execute the call, from the operating system.
6. The operating system (OS) interacts with the
storage media containing the database.
7. The operating system then delivers the
requested data from the actual database to the system
8. The DBMS transfers data, as required to fulfill
the call, between the system buffers and the user work
area (UWA) of Program 1, which originated the call.
Any required data transformations between the
representation of the data as it appears in the database
(as declared in the schema) and the representation of the
data as it appears in a program’s UWA (as declared by
the subschema) are handled by the DBMS.
The DBMS provides status information to program
1 based on the outcome of its call, for example, error
indications. The data in Program 1’s UWA may be
manipulated as required, using the facilities in the host
language. The system buffers are shared by all
programs serviced by the DBMS. Remember,
programs interact with the system buffers entirely
through the DBMS.
Figure 3-15.—A conceptual view of the events that take place
when an application program reads a record in a system
interfaced with a DBMS.
Schema DDL and Hardware
. A conversion procedure has been provided by
the database administrator.
A schema DDL entry does not include references to
a physical device or media space. Thus, a schema
written using a DDL is a description of a database that is
not affected by the devices or media used to store the
data. The database may, therefore, be stored on any
combination of storage media that is supported in a
particular DBMS. Because of their sequential nature,
some devices, such as magnetic tape, may not take full
advantage of the facilities included in a DDL. Such
devices are not precluded, however, and may be
perfectly adequate for some of the data.
The implementor is responsible for defining the
correspondence between the schema data types and
specifications and the sub schema data types and
specifications, in terms of the representation of these
respective data types in the implementation. An
example of a correspondence that might be established
by an implementor would be correspondence between
coded arithmetic data in the schema and
COMPUTATIONAL data in the COBOL subschema.
The implementor might provide special conversion
procedures in addition to those in the DBMS for
implementing the conversion rules. An example of a
case where the implementor might provide a special
conversion procedure would be in the interface between
the DBMS and database procedures written in
particular host languages. If the DBMS supplies a
standard parameter list to database procedures, the
representation of some of the parameter values might
not match that of any data type in a particular host
language. In this case, the implementor might wish to
provide a standard conversion procedure to allow the
host language to correctly access such values.
Chances are the DDL you are using will follow the
guidelines created by the Conference on Data Systems
Languages (CODASYL) and their subcommittee, Data
Base Task Group (DBTG). These guidelines have
influenced the development of database systems,
particularly those for the larger computer systems.
Because of space limitations, the format
specifications for a DML and a schema DDL are not
presented. The syntax rules for a data description
language are similar to those for COBOL and are too
technically extensive to include in this chapter. For
example, a DDL has a character set, words
(programmer supplied), reserved words, key words,
names, literal and nonnumeric literal formatting, and
many other qualification rules.
Developers of host language database facilities
may provide rules defining the intended
correspondence between data types allowed in their
host language subschema DDL and the data types in the
schema DDL. Such rules may be specified directly,
naming characteristics of subschema data types so that
they can be matched with the characteristics of schema
data types. Different host languages may define their
rules for intended data type correspondence in terms of
the closest schema equivalents; for example,
FORTRAN referring to schema TYPE specifications
and COBOL referring to schema PICTURE
specifications. In this case, the conversion rules
specified as part of the schema DDL may be used in
determining appropriate conversions involving data
types not explicitly mentioned in the host language’s
defined rules. For example, the COBOL database
facility might specify the intended correspondence
between its subschema PICTURE specifications and
schema PICTURE specifications. With the
correspondence between schema and subschema
PICTURES established, subschema PICTURE
specifications may be interpreted as if they were
schema PICTURE specifications. The schema DDL
defined conversion rules (which define conversions
between schema PICTURES and other schema data
types) can then be used to determine appropriate
Schema/Subschema Data Conversion
Since data description in the subschema is host
language oriented, the syntax used in the subschema to
describe the characteristics of data items may differ
from that in the schema or storage schema. This means
that data types that turn out to have the same
representation in a given implementation may be
described differently in the schema and storage schema
than in the subschema. Also, there maybe data types
defined in the subschema that have characteristics and
representations different from those of any schema
type, and vice versa. However, any data item
description is eligible for inclusion in a subschema for a
particular host language subschema data description
entry if one of the following conditions is satisfied in the
implementation involved:
l The data item has the same representation both in
the database and in the UWA in that implementation,
l A conversion procedure has been provided by
the implementor, or
The database administrator may allocate media and
devices with differing characteristics to suit the
command’s operational requirements, without
alteration to the storage schema.
conversions between subschema PICTURES and any
schema data type.
Schema DDL and DML
The relationship between a schema DDL and a
DML is the relationship between declaration and
procedure. The DDL declarations impose a discipline
over the executable code and are to some extent
substitutes for procedures written in the DML and the
host language.
Database Management System Selection
When selecting a DBMS, the primary consideration
should be to select a technology that will support the
long-term DBMS needs. The work of identifying the
needs of the command should be done in a very careful
and thorough manner. The ultimate goal is to make the
best choice for the command.
To specify the relationship between DDL
declarations and DML commands, a set of basic data
manipulation functions must be defined that is
independent of the DML and the host language.
Specific commands provided by a particular DML must
be resolved into those basic functions. The resolution is
defined by the implementor of the DML.
One of the best ways of identifying the needs of the
command is to conduct interviews with the users. The
results of the interviews will identify areas of concern to
them, such as:
. How fast can data be accessed?
The basic data manipulation functions assumed in
these specifications include the functions required to:
. How easy is it to retrieve and manipulate the
. Select records
. How fast and easy is it to develop quality
l Present records to the run unit
. Add new records and relationships
l Will the redundancy of data be reduced?
. Change existing records and relationships
. Will it provide for the management and accurate
identity of all the data elements?
. Remove existing records and relationships
Once the needs of the command have been
identified, it is time to prepare the presentation for
management. A first step in the preparation of the
presentation is to describe how the needs of the
command will be addressed by the DBMS. Develop
specific examples to illustrate how each item identified
would be handled in the database environment.
Schema and Storage Schema
The concept of separate schema and storage schema
allows the separation of the logical description of the
entire database from the storage description of the same.
This concept is significant from the following points of
After receiving permission from management to
continue, you can start the selection process. Since all
DBMS software is not the same, you must look at the
quality of the product and the ability of the vendor to
continue to enhance the product in the future. All of the
decisions should be based on the features currently
available or in a beta testing environment. The goal is
not to find the perfect DBMS, but to identify and
recommend the best of those available that will meet the
command’s needs.
1. A database administrator may design a schema
structure consisting of logical record relationships that
sensibly match the totality of applications under
implementation or likely to be implemented.
2. Efficiency considerations are separated from
the logical description by specifying the storage
environment and schema to storage schema mappings
in the storage schema. Tuning may be carried out by
changing the storage schema without alteration to the
schema, subschemas, and programs.
This selection criteria applies whether the DBMS is
going to be used on a mainframe computer or a
microcomputer system. However, the microcomputer
system has a few added concerns that must be met. The
most important of these concerns are:
The storage schema describes the representation of
stored data in device independent terms. The database
may, therefore, be stored on any combination of storage
media that is supported by a particular implementation.
The programmer will be the one to decide the
organization of the database and to define the physical
structures of the database management system.
Programs to process the transactions and to generate the
anticipated management information and decision
support reports are mapped out, using the pseudocode
and flowcharts. Once the programs are mapped out,
they are written, tested, and implemented, creating the
database management system.
l The capability of receiving downloaded data
from a mainframe or another microcomputer
l The ability to be used on a network
l The ability to enable quick and easy setup of
screen formats
l The ability to handle a maximum number of
records, fields, tables, and so on, and the size of
l The ability of the software to accept files in
multiple formats and to transport files and
records out to other microcomputer packages
As a communications specialist, you need to know
a lot more about computers than just how to operate
them. You must have a good working knowledge of
computer software. You should be able to explain and
demonstrate how to use systems and applications
software to both communications specialists and enduser personnel. You will need to interact with the users
to determine their requirements and needs. We covered
how to determine system software and hardware
requirements and the importance of calculating
memory requirements. We discussed the parts of a
database management system (DBMS) and the
selection process for a DBMS, including those for
personal computers.
To decide on the logical structure to use with a
DBMS, you will need to first perform a comprehensive
review of the data. Determine what data is needed,
where the data comes from, and how the data will be
used. Look at the reports needed. Find out what
transactions and displays are most appropriate for
collecting and manipulating the data. At this point, you
can determine what programs and queries will need to
be developed and decide on the best organization for the
CERTIFIER— The piece of equipment that is used to
certify magnetic tape and check for errors.
ABORT— Procedure for terminating a program when a
mistake, malfunction, or error occurs.
COBOL (COmmon Business Oriented
Language)— A high-level programming language
designed for business-type applications.
Ada— A high-level programming language designed
by the Department of Defense.
COMPILER— A program that translates a source
program written in a high-level programming
language into machine language.
ADDRESSING— Locating a required piece of data by
specific techniques.
ARITHMETIC-LOGIC UNIT— The part of the cpu
that contains the logic capability and performs all
the arithmetic functions (addition, subtraction,
multiplication, and division).
CONTROL MEMORY— RAM consisting of
addressable storage registers, primarily used in
mini- and mainframe computers.
a machine to perform human-like intelligence
functions, such as learning, adapting, reasoning,
and self-correction.
DEGAUSSER— Device used to erase information
from magnetically recorded media, such as a floppy
disk or magnetic tape.
ASSEMBLER— A computer program that translates
assembly language programs into machine
language (object) programs.
Indicator lights used to help isolate a hardware
DIAGNOSTIC ROUTINE— Routine designed to
locate a malfunction in the central processing unit
or a peripheral device.
BASIC (Beginners All-Purpose Symbolic
Instruction Code)— A high-level, generalpurpose programming language used primarily on
DISTRIBUTED SYSTEM— A computer system
designed to operate as a communications network
with al1 its terminals linked to a remotely located
central processing unit.
BIT MAPPING— A data structure that describes a bit
image being held in computer storage.
BUBBLE MEMORY— Method by which information
is stored as magnetized dots (bubbles) that rest on a
thin film of semiconductor material.
DUPLEX— Pertaining to a communications system or
equipment capable of transmission in both
C++ — An object-oriented
programming language.
EXTERNAL DIAGNOSTICS— Diagnostics that can
be run from a peripheral device.
CACHE MEMORY— A faster memory in which parts
of the information in the main (slower) memory or
disk are copied.
FILE FRAGMENTATION— Files that are split into
many noncontiguous areas on the disk.
C A R R I E R P A C K A G E — The portion of the
microprocessor chip that plugs into the
FINITE— To have limits, an end, or a last number.
FIVE-PIN CONNECTOR— A connector that has five
pins, usually used to connect a keyboard to the
produces high--quality printed output from a
FORTRAN (FORmula TRANslator)— A high--level
programming language for scientific and
mathematical applications.
LIBRARIAN— Person responsible for the safekeeping
of all computer files, such as diskettes, disk packs,
and magnetic tapes.
LOCAL-AREA NETWORK— A network that
normally operates within a well-defined and
generally self-enclosed area. The communication
stations or terminals are linked by cable.
HARD-SECTORED— Wedge-shaped storage
division on a floppy disk from time of manufacture.
refer to the organizational method of arranging files
either in a DOS tree structure or in the file-andfolder method.
HUB— The center part of the tape reel that attaches to
the tape drive.
HYPERTEXT— A document retrieval network having
till-text files and dynamic indexes for links among
MAGNETIC CORE STORAGE— System of storage
in which data is represented in binary form by
means of directional flow of magnetic fields in tiny,
doughnut-shaped arrays of magnetic cores.
HYPOTHERMAGRAPH— A piece of equipment
that is used to record the temperature and humidity
in a computer room.
MAGNETIC DOMAINS— The data that is stored by
changing the polarity of the magnetized dots
MAINFRAME COMPUTERS— This term is usually
used to designate large-scale computer systems,
although the precise definition of mainframe is the
cpu and the control elements of any computer
the control section that includes the combinational
and sequential circuits that make up the decisionmaking and memory-type functions.
MATRIX— Orderly array of symbols by rows and
INTEGRATED CIRCUIT— A miniaturized chip in
which semiconductor components and other such
technology combine the functions of a number of
conventional components (such as transistors,
resistors, capacitors, and diodes).
MINICOMPUTERS— Midsize computers that are
smaller than large-scale systems but with the same
components. They are less expensive and have less
strict environmental requirements.
MODEM— A device that converts data from digital to
analog format for transmission on analog
transmission lines, and also converts data in analog
format to digital format for computer processing.
INTERNAL DIAGNOSTICS— Diagnostics that are
run when the computer is started.
IPL (Initial Program Load )— A set of instructions that
cause other instructions (the operating system) to be
loaded into the main memory of the computer. This
must be done each time the computer is turned on.
the operating system that allows for several files to
be contained in a directory.
JULIAN DATE— Form of calendar representation
within a computer system, indicating the year and
the number of elapsed days in the year.
NONVOLATILE STORAGE— Storage medium that
retains its data in the absence of power.
SCSI ADAPTER— A general purpose parallel
interface designed for connecting one or more
computers and one or more peripherals. A total of 8
devices may be connected to one bus.
OXIDE— A ferrous material that can be magnetized;
also, the recording side of the magnetic tape (dull
SEMICONDUCTOR— A crystalline substance that
conducts electricity when it is “doped” with
chemical impurities.
elements of a word or message simultaneously.
SERIAL— Pertaining to the sequential occurrence of
two or more related activities in a single device.
PASCAL— High-level structured programming
language that has gained wide acceptance as a tool
for both applications programming and system
SILICON CHIP— Tiny portion of a silicon wafer with
thousands of electronic components and circuit
patterns etched on its surface.
PENTIUM CHIP— A processor chip that can execute
many instructions at the rate of two instructions per
clock cycle.
SIMPLEX— A mode of data transmission in which
data can travel in only one direction on the line.
When a terminal is connected to such a circuit, it
can be used to either receive or send data to the cpu
but not do both.
PERIPHERAL EQUIPMENT— Equipment used for
data entry, storage, or retrieval, but which is not part
of the central processing unit. Peripherals include
crt displays, terminals, printers, and mass storage
(tape, disk, and drum) devices.
operating system that allows for only one file to be
contained in a directory.
PHOTOELECTRIC CELL— A mechanism that
when activated by a light source emits an electrical
SOFT-SECTORED— Method of marking sectors or
sections on a disk by using information written on
the disk.
SPECIAL FUNCTION KEY— Key on a keyboard to
control a mechanical function, initiate a specific
computer operation, or transmit a signal that would
otherwise require multiple key strokes.
QUERY— To make a request for information from a
database system.
STAND-ALONE— Self-contained computer system
that can work independently, not connected to or
under the control of another computer system.
RECONCILING— Refers to the correcting of
processing discrepancies.
STRIPPING— The removing of the first 100 feet of the
magnetic tape. This is the portion that becomes
contaminated and causes the most errors.
R E L A T I O N A L D A T A B A S E — A database
organization scheme that treats files as tables of
data in which the rows represent fixed-length
records and columns represent fields.
SUBSCHEMA— Logical organization of data
required for a particular program.
RIGID— Refers to the hard metal platters (usually
constructed of aluminum or glass) that comprise a
hard disk.
SURGE PROTECTOR— Device that protects
electrical equipment from being damaged by short
surges of high voltage by filtering them out.
SCHEMA— Structure for organizing knowledge
relative to context or expectations.
TIMING— The regulation of the flow of signals that
control the operation of the computer.
magnetic media available to the computer operator
for reuse.
containing a root directory and several
serial connector that has twenty-five pins, usually
used for connecting a printer or monitor to the CPU.
only one directory contained on it.
VIRUS— A computer program which can wreak havoc
on a system, either by destroying data or simply
changing and slowing up the processing of the
UNIX— An operating system that has many high-level
utility programs; it is capable of running a number
of jobs at once.
ABEND— Abnormal end of job.
LAN— Local--area network.
LQ— Letter quality.
ALCS— Automated library control system.
ALU— Arithmetic/Logic unit.
ATLC— Automated tape library control.
LSI— Large-scale integration.
MODEM— Modulator-demodulator.
CAD— Computer-aided design
PROM— Programmable read-only memory.
CMOS— Complementary metal oxide semiconductor.
CODASYL— Conference on data systems languages.
COOP— Continuity of operations.
QWERTY— Refers to the letter sequence QWERTY
on the keyboard.
CPU— Central processing unit.
RAM— Random-access memory.
DASDI— Direct access storage device initialization.
ROM— Read-only memory.
DBMS— Database management system.
DBTG— Database task group.
DDL— Data definition language.
SOP— Standard operating procedure.
DML— Data manipulation language.
SYSRES— System resident.
DOS— Disk operating system.
DTP— Desktop publishing.
UWA— User work area.
E P R O M — Erasable programmable read-only
VLSI— Very-large-scale integration.
IC— Integrated circuits.
WORM— Write once, read many.
IPL— Initial program loading.
WYSIWYG— What you see is what you get.
NOTE: The following references were current at the time this
TRAMAN was published, but you should be sure you have the
current editions.
American National Dictionary for Information Processing Systems, Federal
Information Processing Standards (FIPS) Publication 11-3, U.S. Department of
Commerce, National Bureau of Standards, Washington, DC, 1991.
Banks, Michael, The Modem Reference, Second Edition, Brady Publishing, New
York, NY, 1991.
Cannon, Don L., Gerald Luecke, Understanding Microprocessors, Howard W.
Sams and Co., Indianapolis, IN, 1984.
Mueller, Scott, Upgrading and Repairing PCs, Fifth Edition, Que® Corporation,
Indianapolis, IN, 1995.
Norton, Peter, and Robert Jourdian, The Hard Disk Companion, Simon&Schuster,
Inc., New York, NY, 1988.
O’Leary, Timothy and Linda, Microcomputing, Annual Edition 1994-1995,
McGraw-Hill, Inc., New York, NY, 1994.
Prasad, Nallur, Jeffrey Savit, IBM Mainframes Architecture and Design, Second
Edition, McGraw-Hill, Inc., New York, NY, 1994.
Simon, Alan R., The Computer Professional’s Survival Guide, McGraw Hill, Inc.,
New York, NY, 1992.
Spencer, Donald D., Ph. D., Computer Dictionary, Fourth Edition, Camelot
Publishing, Co., Ormond Beach, FL, 1993.
Wang, W. E., Joe Kraynak, The First Book of Personal Computing, Second Edition,
SAMS, Prentice Hall Computer Publishing, Carmel, IN, 1990.
Database management system selection, 3-26
AIS service requests, 2-8
Database organization methods, 3-12
Applications software, 3-2
hierarchical, 3-13
Arithmetic-logic unit, 1-2, 1-3
list, 3-13
Auxiliary storage, 1-6
network, 3-13
relational, 3-14
Diagnostic/troubleshooting, 1-26
Bit mapping, 1-16
Diskettes, 1-19
care, 2-29
Documentation, 1-24,2-6
Duplex, 1-9
Cables, 1-28
fill-duplex, 1-9
Computer output, 2-2
half-duplex, 1-9
Console operations, 2-2
booting the system, 2-4
computer diagnostics, 2-4
External labels, 2-11
console keyboards, 2-3
nonpermanent, 2-12
configuration changes, 2-3
permanent, 2-12
powering up the system, 2-4
Control keys, 1-17
Control panel, 1-22
File and disk management, 2-26
Control unit, 1-3
File fragmentation, 2-34
File organization, 3-20
direct, 3-20
indexed sequential, 3-20
Data management, 3-1
Data transmission methods, 1-9
sequential, 3-20
Floppies, 1-19
parallel, 1-9
serial, 1-9
Database management systems (DBMS), 3-21
Hard disks, 1-20
data manipulation languages (DMLs), 3-24
Help aides, 1-25
DBMS events, 3-24
High-level languages, 3-3
schema, 3-22
ADA, 3-3
schema data definition language (DDL), 3-23
BASIC, 3-3
subschema, 3-23
C++, 3-3
High-level languages—Continued
Library functions, 2-8
COBOL, 3-3
care and handling, 2-14, 2-16
cleaning and recertifying, 2-17, 2-19
degaussing, 2-20
Hypothermagraph, 2-2
destruction, 2-20
disaster/off-site backup, 2-13
labeling magnetic media, 2-10
receipt of magnetic media, 2-10
Input/ouput (I/O) channels, 1-9
releasing magnetic media, 2-21
duplex, 1-9
shipment, 2-14
simplex, 1-9
storage, 2-21
Input/output devices, 1-14
CD-ROM drive, 1-23
Loading and unloading tapes, 2-31
paper forms, 2-32
disk drives, 1-18
tapes, 2-31
keyboards, 1-16, 1-28
modems, 1-24
monitors, 1-14, 1-27
Magnetic disk, 2-16
mouse, 1-23
care and handling, 2-16
optical scanner, 1-23
cleaning and recertifying, 2-19
printers, 1-21, 1-28
Magnetic media administrative duties, 2-24
switch boxes, 1-24
Magnetic tape, 2-14
care and handling, 2-14
tape drive, 1-23
cleaning and recertifying, 2-17
I/O and program specifications, 3-20
Main memory, 1-3
Management of classified media, 2-23
Memory classifications, 1-5
Jobs, 2-5
canceling, 2-6
erasable programmable read-only memory
(EPROM), 1-6
displaying, 2-5
programmable read-only memory (PROM), 1-6
monitoring, 2-8
random-access memory (RAM), 1-6
restarting, 2-5
read-only memory (ROM), 1-6
starting, 2-5
Memory types, 1-4
bubble storage, 1-5
magnetic core storage, 1-4
Labels, 2-10
semiconductor storage, 1-4
external, 2-11
Messages, 2-4
internal, 2-13
program-generated, 2-5
Library environment, 2-22
system-generated, 2-4
Microprocessor chip, 1-13
Modems, 1-10
spreadsheet, 3-9
Motherboard, 1-12
utilities, 3-17
word processing, 3-7
Software installation, 3-3
Naming files, 2-26
application, 3-3
operating system, 3-3
Operating environment, 2-2
Software packages, 3-5
Special function keys, 1-17
Specialized processors, 1-14
Peripheral devices, 1-6
Storage area, 1-3
bar-code readers, 1-7
input, 1-3
cathode-ray tube (CRT) terminals, 1-8
output, 1-3
computer consoles, 1-8
program, 1-3
floppy disk drive units, 1-8
working, 1-3
key-to-online data entry terminals, 1-7
Storage capacity, 1-19
magnetic disk drive units, 1-8
Surge protector, 1-27
magnetic ink character readers, 1-7
System care, 2-30
magnetic tape units, 1-7
System configuration, 1-28
plotters, 1-9
System software, 3-2
printers, 1-8
assemblers and compilers, 3-2
scanners, 1-7
operating systems, 3-2
Power requirements, 1-26
Primary storage, 1-3
utilities, 3-2
System unit, 1-11, 1-27
Programming languages, 3-2
assembly languages, 3-3
high-level languages, 3-3
Tape retention, 2-26
machine languages, 3-2
Trouble reports, 2-1
Troubleshooting, 2-34
Resolution, 1-15
User requirements, 3-19
Secondary storage, 1-6
hardware, 3-19
Shift operations, 2-7
memory, 3-19
Software, 3-3
software, 3-19
database, 3-11
Users, 3-5
desktop publishing, 3-15
User/owner manuals, 1-25
Utilities, 3-17
backup, 3-18
file management, 3-18
desktop organization, 3-18
keyboard enhancement, 3-17
DOS shells, 3-18
printer, 3-18
file maintenance, 3-18
virus, 2-8, 3-18
Assignment Questions
Information: The text pages that you are to study are
provided at the beginning of the assignment questions.
“Computer Hardware
through 1-25.
The central processing unit
of a digital computer is
made up of a central control
section and work areas that
are needed to perform
calculations and manipulate
What are the names of
the sections within the CPU?
Within the CPU, the internal
storage section normally
contains which of the
following storage areas?
What type of storage
(memory) allows you to enter
any program you desire, but
once the memory has been
written into, it can never
be altered or changed?
Input and output only
Output and program only
Input, program, and
working only
Input, output, program,
and working
Most computers can
permanently store often used
instructions, such as those
used to boot-strap the
computer, in memory.
type of memory makes this
Within the CPU, what section
maintains order and directs
the flow of operations and
What type of memory allows
you to read data from or
write data into it just by
giving the computer the
address of the location
where the data is stored or
is to be stored?
Control, internal
storage, and
Control, working
storage, and programming
Internal storage,
and internal storage
Which of the following types
of storage is normally
outside the main body of the
computer and is used to
store programs and data for
future use?
Map storage
Hyper storage
Secondary storage
Peripheral storage
Anytime an input or output
device is under the direct
control of the CPU, we say
the device is in what mode?
An I/O channel that is
capable of communicating in
both directions but in only
one direction at a time is
what type of channel?
Under full-duplex I/O
communications are possible
in which of the following
Which of the following
components is NOT considered
an input/output (I/O)
Computer terminal
Floppy disks
Magnetic tape unit
Whether an I/O channel is
input only, output only, or
both input and output is
determined by what person or
primary factor?
Which of the following
devices is used to convert a
digital signal produced by
your terminal to an audio
signal suitable for
transmission over a
communication line?
From the computer to the
terminal only
From the terminal to the
computer only
In both directions
In both directions, one
direction at a time
When data is transmitted
over a communications
channel in a serial fashion,
the data is sent or received
in which of the following
The systems analyst
The design of the CPU
The specific type of
peripheral device
A line conditioner
A signal generator
What microcomputer unit
processes the data, performs
arithmetic and logic
functions, and maintains
control of the system?
The system board (mother
board) contains which of the
following types of chips?
System unit
Display unit
Hard disk drive
The disk controller board,
video board, and
input/output boards are
plugged into what board?
what three types of
Compared with a computer
that processes 8 bits at a
time, a computer that
handles 32 bits at a time
has which of the following
Memory, control logic,
and instruction decoding
Memory, instruction
decoding, and
Operating system,
control logic, and
Control logic,
RAM and ROM only
RAM, ROM, and I/O
integrated chips only
I/O integrated circuit
chips and microprocessor
chip(s) only
RAM, ROM, I/O integrated
chips, and
microprocessor chip(s)
Processes program
instructions faster
Can accommodate a larger
primary memory
Both 1 and 2 above
Can accommodate a modem
3 .
What type of chip is the
System unit
Display device
Cathode-ray tube
Raster gauge beam
Registered global beam
Light-emitting diode
Light-enhancing diode
Low-emitting device
Low-enhancing device
Dot mapping
Line drawings
Opaque images
To individually control each
dot or pixel on a display
screen, what technique can
be used?
1, 024
By what means are characters
created on the screen?
Most monitors will have an
LED indicator light.
does LED mean?
Screen size
A screen with a resolution
of 1280 by 1024 has what
total number of pixels?
Screen size
The number of dots or pixels
per square inch of screen
measures what
Depending on the amount of
RAM available, color
monitors can display what
range of colors?
What characteristic
determines the sharpness of
the monitor screen image?
Most color monitors are of
What does RGB
the RGB type.
I/O circuit
Math coprocessor
Which of the following terms
is NOT used interchangeably
with the term monitor?
Having a display device that
can automatically switch to
any standard graphics card
allows you to take which of
the following actions?
Upgrade the graphics
board without upgrading
the display unit
Use any graphics package
regardless of operating
Perform system and
display diagnostics more
Each of the above
Keys can be combined to
perform special functions.
For example, pressing the
CTRL, ALT, and DEL keys at
the same time on most IBM
systems would have what
What is the function of the
To receive output from
the microcomputer
To input data into the
microcomputer only
To input programs into
the microcomputer only
To input data and
programs into the
To tell the computer you
have entered data or
instructions and are ready
to have them processed, you
should press what key(s)?
In addition to alphabetic
characters, numbers, and
keyboards have what other
types of keys?
Control only
Function only
Control and function
What key usually stops the
execution of an operation or
Tab only
Ctrl and Tab
Ctrl and Alt
Function keys F1-F10 are
specifically designed for
what purpose?
Reboot the operating
Load a new applications
Display a help screen
Store the file displayed
on the screen
To provide standard
information to all
To control cursor
placement on the screen
To be defined by each
program for its own use
To allow changing the
size of the characters
displayed on the screen
What are the functions of
the left and right arrow
To move the cursor one
position left or right,
To move the cursor one
line up or down,
To insert a character to
the left or right of the
position of the cursor,
To delete the character
to the left or right of
the cursor, respectively
F1 through F10
Print screen, delete,
and insert
Numbers and special
Alternate, space bar,
and enter/return
Cursor control
Tab and control
Letters and numbers
Space bar and back space
Which of the following
properties is NOT a
characteristic of a disk?
Direct access
and 5
5 1/4
and 5 1/4
Marks the first sector
of the diskette
Indicates the front side
of the diskette
Indicates the back side
of the diskette
When software controls
sector timing of diskettes,
(a) what sector type is
being used, and (b) which of
the following numbers of
timing holes are required on
the diskette?
Floppy disk
Read-only disk
Write-only disk
Hard disk
The index hole on a diskette
serves which of the
following purposes, if any?
Diskettes come in which of
the following sizes, in
Which of the following types
of keys are examples of
special function keys?
Diskettes are also known
which of the following
Which of the following types
of keys are examples of
control keys?
One only
One only
What is the purpose of a
formatter program, routine,
or command?
To sector a
soft-sectored diskette
To create file labels on
a diskette
To establish a naming
pattern for writing
files on a diskette
To set up a routine to
be used to read a
diskette that already
contains files
Cover it
cover it
Cover it
uncover it
Uncover it
cover it
Uncover it
uncover it
Hard disks
Paper tape
Magnetic tapes
Low speed, one character
at a time
Low speed, one line at a
High speed, one
character at a time
High speed, one line at
a time
Which of the following types
of nonimpact printers can be
used for both printing and
Printers used with microcomputers usually have which of
the following speeds and
print characters in what
Winchester only
Hard disk only
Winchester or hard
Speed, large storage
capacities, and
are all advantages of which
of the following storage
You want to prevent data
from being written on a
What should you
usually do to the
write-protect notch if you
are using a (a) 5 l/4-inch
diskette and a (b) 3
Rigid metal platters
contained in a small sealed
unit either within the
system unit or external to
it are called what type of
disk drive?
A diskette that can be
written on both sides and
can hold 512 bytes of
information in each sector
is what type of diskette?
Ink jet
Control panels allow you to
select various settings on a
What is the
purpose of a form-feed
T O eject paper from the
To advance the paper to
the top of the next form
To allow you to select
reprinted forms
To advance the paper 1
1/2 inches
The power light on, the
online light off, and
the error light off
The power light on, the
offline light on, and
the error light on
The power light on, the
online light on, and the
error light off
The power light on, the
offline light on, and
the error light off
To freehand sketch or to
select items from menus on a
display screen, you use what
User/owner’s manual
Diagnostics manual
Which of the following
sections is NOT contained in
the manuals that come with a
system or the software?
convert cable
phone cable
null modem cable
connector cable
To find out how to install
or configure a piece of
hardware, you should use
what reference source?
Write or read many
Write once, read many
Write or read memory
Write once, read memory
A cable that allows devices
to communicate without
modems and phones lines is
called a
Before a printer can print,
the indicator lights must be
in which of the following
CD-ROM uses a technology
called WORM.
What does WORM
Error messages
Standard operating
You should look at the
headings in the table of
contents and browse the
appendices, glossary, and
index of a manual for which
of the following reasons?
Keyboard templates and
reference cards are useful
because they provide which
of the following
To get an idea of what
information the manual
contains only
To see how the
information is organized
To get an idea of what
information the manual
contains and how it is
To decide whether to buy
additional copies
Online tutorials that come
with software packages
usually have which of the
following purposes?
In-house user manuals have
which of the following
To teach all the
commands of the software
To give you an overview
of what the software can
do and how it works
To drill you in keying
the correct information
for specific
To help you memorize all
the functions and
about each feature
features and associated
Keyboard schematic with
a detailed description
of each key and all its
Keyboard schematic with
the ASCII coding
associated with each key
To implement command
policy only
To implement command
procedures only
To implement command
policy and procedures
To implement security
regulations only
Which of the following
devices,if any, gets its
power supply from the system
unit rather than through its
own power line cable?
Fuse box
Surge protector
Gender changer
Surge protector
Surge protectors
What type of distinctive
function keys, provided by
the manufacturer, provide
faster and easier
performance of routine
What instrument is used to
monitor both temperature and
humidity in a computer
Which of the following types
of devices can usually
operate in either a serial
or a parallel mode?
There is a problem with
hardware that you cannot
There is a problem with
software that you cannot
Both 1 and 2 above
The system is completely
Computer rooms
preset temperatures to
prevent equipment failures.
Regardless of temperature
requirements, which of the
following temperature ranges
is most often maintained in
computer rooms?
What device has a cable with
a twenty-five pin serial
connector to connect it to
the system unit?
What is the criteria for
submitting a trouble report?
High voltage can overload
and literally burn up the
computer’s internal
To avoid high
voltage peaks, you should
use what device?
“Computer Hardware Startup (continued),” chapter 1,
pages 1-26 through 1-29; “Computer Center Operations,”
chapter 2, pages 2-1 through 2-35; “Data Management,”
chapter 3, pages 3-1 through 3-6.
When powering up a computer
you should power up the CPU
first, then each piece of
equipment individually for
which of the following
To save time
To save power
To prevent a surge of
To verify all the
indicator lights are
As a computer console
operator, you normally have
to reboot (IPL) the computer
system after each of the
following conditions except
which one?
The system has lost
The system has gone into
a wait state
The system is shut down
for repairs
The system is disabled
due to a system crash
Initiating job log
Displaying job status
Querying job queue
Displaying master
Normally, the programmer
determines the points in a
program where a job can be
restarted without having to
rerun the entire job.
points are known by what
Program and control
User and applications
System and conditional
Operating system and
program generated
As a computer console
operator, you can determine
if a job is active, stopped,
terminated, or waiting for
printer by performing which
of the following console
Some mainframe computers use
a disk to store their
operating system. This disk
is known by which of the
following names?
As a computer console
operator, you are
responsible for responding
to messages from the
Basically, you
are concerned with what two
types of messages?
Program checks
Cutoff points
What are the two types of
computer diagnostics?
When a program is cancelled
or terminates abnormally, i
is said to have
When a program abnormally
terminates, you will
normally be required to dump
the contents of storage for
which of the following
What makes up a basic virus?
To save space on the
storage media
To allow for
reconstruction of the
input data
To help the programmer
analyze the program
To clear out the problem
area that caused the
abnormal termination
What is/are the main
reason(s) for relieving
shift 15 to 30 minutes
Get acquainted with
jobs running
Provide constancy
between shifts
Provide continuity
between operators
All of the above
Magnetic tape must be
acclimated to the atmosphere
in which it will be used for
what minimum period of time?
If a job terminates before
going to a normal EOJ, you,
as the I/O control clerk,
may be required to collect
which of the following
Output data and memory
dump only
Input data and SCL
statements only
Input data, output data,
and memory dump
Output data, console
printout, and SCL
A media librarian is NOT
expected to perform which
the following tasks?
A malicious program
segment that leaves no
obvious signs of its
Complex instructions
that have been designed
to stop your computer
system from booting up
A malicious program
segment that creates
obvious signs of its
Complex instructions
that cause the
peripheral devices to
log on and off by
Maintain off-site
storage tapes and disks
for disaster recovery
Maintain control of data
files, program files,
and various types of
File all library
materials in a neat,
organized, and uniform
Make necessary SCL
program changes prior to
releasing jobs from the
What is the total number of
90-day extensions that may
be granted before the tape
is copied to another tape?
It indicates how often a
tape is to be certified
It helps to identify
what has been previously
written on the media
It contains information
that helps to identify
the job or task number
It indicates the number
of times a tape has been
read from or written to
When using internal
labeling, how many blocks of
information, if any, are
written immediately after
the BOT marker?
and EOF
and external
and media
and BOF
On magnetic tape, what is
the purpose of the usage
The protective covering
is still on the tape
The warranty of the
manufacturer is in
Verification of the tape
with a tape
Visual inspection of the
shipping container,
looking for physical
Which of the following
labels remains on a magnetic
tape throughout its life
Media librarian
Local fire marshal
Damage control petty
Computer operations
What are the two types of
labels used for magnetic
As media librarian, you are
NOT responsible for the
initial preparation of which
of the following tape
As media librarian, you have
just removed a new tape from
the shipping container.
Which of the following
factors or actions ensures
that nothing is internally
wrong with the tape?
What person is responsible
for updating fire-fighting
instructions and ensuring
fire-fighting equipment is
maintained in the magnetic
media library?
Which of the following is a
good tape handling practice?
Store magnetic tape in a
horizontal position
Stack tapes with
wrap-around straps in
stacks of 20
Carry magnetic tape by
the center hub, never
the flanges
Using both hands, mount
tape by applying an even
amount of pressure to
the outer flange
By the handle located on
the top cover
By the handle located on
the bottom cover
By placing both hands on
the bottom cover
Under your arm, so it
will not get away from
In the
On the
the last 100
middle of the
edges of the tape
Wiping assemblies
Wiping assemblies
Soft data checks are also
called what type of errors?
(a) One
(b) to relieve tape
(a) One
(b) to help prevent head
(a) Two
(b) to relieve tape
(a) Two
(b) to help prevent head
When you are cleaning a
tape, (a) what is used to
remove protrusions from the
oxide surface, and (b) what
is the maximum percentage of
tape errors that are
When you are working with
magnetic tape, the greatest
number of tape errors are
normally found in what area
of the tape?
A new tape should be cleaned
(a) a minimum of how many
times, and (b) for what
Whenever you are retrieving,
storing, or handling a disk
pack, you should always
carry it in which of the
following ways?
Hard parity
Head-to-disk contact
What action does the
degaussing of magnetic
Sorts out individual
Rearranges all
alphabetic and numeric
the oxide coating and
rearranges all 0 and 1
Demagnetizes the media
and then replaces EOT
and BOT markers with
up-to-date labels for
Local SOPS
Most AIS installations have
incorporated or are capable
of installing an automated
tape library control (ATLC)
Which of the
following processes takes
place in an ATLC system?
Under an ATLC system, what
report indicates the tapes
that are to be scratched or
What guidelines, if any, do
you use to destroy magnetic
tape and diskettes?
The diskette should be
inserted in a horizontal
diskette drive with (a) the
label and (b) the recording
window facing in which of
the following directions?
When you display a
on a monitor screen, what
notation identifies
toward the drive
away from the drive
toward the drive
away from the drive
What is the extension of a
file named DIAG-A.89?
Save labels are
automatically scanned by
an optical reader
Storage, handling, and
retrieval of magnetic
media are done
Tape/disk files are
retained, and scratched,
based on purge dates
Information needed to
build an ATLC master
record is automatically
extracted from the
media’s internal label
The library maintenance
The media to be released
The applications report
SUB as an
What command is used to
instruct DOS to create a
Branch name
Trunk name
Path name
Leaf name
Make backup copies
Enter security codes in
the file name
Assign a volume number
and name to each disk
Use subdirectories to
store similar data and
Upper tractors
Lower tractors
Left-hand tractors
Right-hand tractors
On a printer, the paper
thickness control knob has
direct effect on which of
the following printer
The tape tension is
The drive capstans are
not properly aligned
The file protect ring is
not completely inserted
The volume of air in the
vacuum columns is low
When you adjust the tractors
on a printer, it is good
practice to keep which of
the following tractors in
one permanent location?
Perform diagnostic
routines periodically to
see if there are any
Clean floppy disk drives
with a head cleaning
Clean the floppy disk
drives with a cleaning
solution on a soft cloth
Reel warpage
Tape protruding
Irregular winding
All of the above
Assume you have mounted a
tape on tape unit 2 and
notice that during the
loading phase the tape is
Which of the
following conditions could
cause this problem?
Which of the following
actions, if any, can you
take to help prevent data
loss and extend the life of
floppy disk drives?
When you load or unload a
tape from a tape drive,
which of the following
conditions should you look
You run the risk of losing
data and programs stored on
disk if you do not take
which of the following
To move through a
tree-structured directory,
you must issue commands that
use what name?
Forms stacking
Quality of print
Alignment of preprinted
Line-by-line movement of
Your system will probably
provide a read disk test, a
keyboard test, and a
power-up test.
These types
tests are characterized by
what term?
Offline routines
Diagnostic routines
When you write a program,
which of the programming
language categories listed
below would be the most time
There are a whole host of
Which of the
following languages was
designed with the
professional programmer in
Examples of the work
that will be performed
Lists of outputs you
want on a scheduled
All of the above
To make a microcomputer
system easier for the user
to start each day, you
should take what action?
A window program
An operating system
A word processing
A data base management
Which of the following types
of information must you
provide to an applications
software package when you
install it on a
All microcomputer systems
will have at least what type
of software?
Programs that are designed
to solve individual user
problems are called what
type of programs?
2 .
3 .
Software that is
specifically designed to
coordinate the capabilities
of the computer itself is
called what type of
Ada is a registered
trademark of the U.S. Department
Give the user a written
list of specific
instructions to follow
Set the system to
automatically boot when
the user turns on the
Go to each system each
morning and boot the
system for the user
Make arrangements for
one person in each
functional area to boot
all the systems each day
Before turning the power off
on a microcomputer system,
the user should take which
of the following actions?
Word processing
Job control
Access and execute
Save files
Delete files
Run diagnostics
Take the tutorial/study
the learning section
Create a test file and
practice on it
Practice on the master
data file
Make mistakes on purpose
to see how the software
Commands composed of words
by the software to perform
specific tasks are what type
of commands?
Function keys have which
the following purposes?
To perform file management
functions effectively, you
must know which of the
following facts about files?
When you are learning how to
use a software package, you
should NOT take which of the
Regardless of the software
package you are using, it is
NOT mandatory that you be
capable of executing which
of the following operations?
Save his/her work
Exit the program to
return to the operating
Park the read/write
heads if using a hard
Deenergize the system
Packaged software does
include which of the
following software?
How they are set up and
How they are named
How they are backed up
All of the above
To perform user defined
functions only
To perform commonly used
commands without the
user having to type the
To provide user status
information only
To enter data and
When you are learning a new
software package, what
method of interfacing with
the software is usually the
Direct commands
Function keys
Repetitive only
Complex only
Awkward only
Repetitive, complex,
What type of software
package is designed
primarily to work with
Word processing
Type it on a keyboard
Receive it over a
Input it through a
Import it from a desktop
On a secondary storage
None; documents are only
printed, not stored
What feature of word
processing enables you to
continue typing without
regard for where a line
You are using a word
processing program and want
to add new material to a
What mode of
operation should you use?
Once entered, a document is
normally stored as a data
file in what way, if at all?
Function keys
System commands
Job languages
Macro capability
What is the usual method of
entering a document?
Macros can be developed and
stored to perform which of
the following types of
Use of what feature(s)
enables you to enter and
save a series of keystrokes
for later use?
“Data Management
through 3-27.
Word wrap
End around
Automatic return
To underline or center
material, you should use
what feature?
Cursor movement
Function key
Usually, a dictionary is
included with which of the
following software?
Word processing
Desktop publishing
What type of software
package works in columns
2 Tapes
3 Disks
What total number
cells are shown?
B2 only
B2 and C2 only
B2 and D2 only
B2 , C2, and D2
Which of the following names
is/are also used to describe
a spreadsheet?
What value is shown in data
cell B3?
B times column C
B plus column C
C squared
In the spreadsheet, (a) what
term is used to describe the
entries in column A, and (b)
what type of data does
column A contain?
350.00 1400.00
If you need to change the
quantity of tapes and
recalculate the cost, which
data cells would you have to
change from the keyboard?
Desktop publishing
The values in the total
column are calculated by the
software by the user
specifying a formula to
perform what calculation, if
Array only
Matrix only
Worksheet only
Array, matrix, and
What type of software
packages work primarily with
records, fields, indexes,
pointers, and keys?
Key searches
What type of database
structure enables the user
to establish relationships
when requesting information
rather than requiring
relationships be established
at the time the structure is
Import the document file
Rekeystroke the document
Reformat the document
file using a stand-alone
utility program
Translate the document
file using a stand-alone
utility program
Which of the following is
NOT a function of desktop
publishing software?
Word processing
Desktop publishing
When you want to use desktop
publishing software to
process a document you
created with word processing
software, you will have to
take what action?
Network only
Hierarchical only
Hierarchical and network
Report generator
When you want to produce a
high quality printed
document with a variety of
type sizes and styles, what
type of software package
would be best to use?
What type(s) of database
structure link(s) related
data elements by using
With database software, what
name is given to the type of
language used to retrieve
information from a database?
List databases use what
technique to link records?
Word processing
To access records in a
database in a sequence other
than the sequence in which
they are stored, you can use
which of the following
Layout involves which
following tasks?
2 .
3 .
Arranging text only
Drawing borders only
illustrations only
Arranging text, drawing
borders, and
What type of printer is best
to use with desktop
2 .
Letter spacing
You can expect to find which
of the following
capabilities relating to
graphics in a desktop
publishing program?
Resizing only
Importing only
Color layering only
Resizing, importing,
color layering
At a minimum, to effectively
use desktop publishing
software requires which of
the following processors?
A 286 16-bit
A 386 16-bit
A 486 16-bit
A Pentium 32-bit
enhance your computer’s
fill some of the voids
left by operating
systems and applications
replace the need for
application software to
perform tasks like word
processing and database
make your computer more
File maintenance and
file management only
Keyboard enhancers, DOS
shell, and backup
utilities only
printer utilities, and
virus utilities only
File management, file
enhancers, DOS shell,
backup utilities,
printer utilities, and
virus utilities
What type of utility usually
includes a calculator,
notepad, phone directory,
and appointment book?
Software utilities can
categorized into which
the following groups?
The monitor to use with
desktop publishing software
should have (a) what
resolution and (b) at
least what size screen?
Daisy wheel
The space added between
lines of material is known
by what term?
2 .
of the
File management
File maintenance
Desktop organizer
File compression routines
are often a feature of
backup utilities. They have
which of the following
How a file will be accessed
by the program is determined
at which of the following
Manipulate files only
Manipulate files and
Provide file recovery
What person is the primary
source in determining the
input data and output
Indexed sequential
Easy access to the data
Storage and maintenance
of large volumes of data
Capability for sharing
the data resources
None; all are equally
Technical and nontechnical
DBMS users need different
views of data.
In a DBMS environment, users
do not want to share their
data with other users of the
I/O control clerk
Of the following features of
a DBMS, which one, if any,
is more important than the
Encrypt data
Repair low-level format
damage on hard disks
Control access to
resources and files
Organize files and set
file attributes
When the DBMS is
During the creation
the schema
During the creation
the subschema
When the file is
Which of the following is
the most commonly used file
organization method?
File maintenance utilities
are NOT designed to perform
which of the following
File management utilities
perform which of the
following functions?
Make data easier to read
Allow more data to be
placed on a diskette
Require fewer data files
for data storage
Each of the above
A conventional computer
system has few application
programs or systems using
different databases and
The actual data in the
database framework
The software description
of the operating system
An overall logical
database description or
A data aggregate of
owner-type records
data converter
system buffer
I/O control area
user working area
DBMS waiting buffer
A bit in a database
The largest unit of
named data
The smallest unit of
named data
A byte in a database
Each set occurrence must
contain what minimum number
of occurrences if it is
defined as an owner type of
A sort key
A search key
An actual key
A database key
An occurrence of a named
collection of records is
called a
A data item can be described
as an occurrence of which of
the following elements?
(b) different
(b) different
Which of the following is a
unique value that identifies
a record in the database to
a run unit?
A vector is which of the
following (a) sequences of
data items that have which
of the following
All data provided by the
DBMS in response to a CALL
for data is delivered to
what is conceptually a
loading and unloading zone
called a
Which of the following items
enhances security factors
and helps prohibit data
A data aggregate is an
occurrence of a named
collection of data items
within a
Which of the following
defines a DBMS schema?
A named collection of
records that need not
relationships is called
data item
database key
A database consists of all
of the following items
controlled by a specific
schema except which one?
The object program
The console operator
User work area (UWA)
System buffers
areas 1
Literal formatting only
Key words only
Reserved words only
Literal formatting, key
words, and reserved
To specify the relationship
between DDL declarations and
DML commands, a set of basic
data manipulation functions
must be defined that is
independent of which of the
following languages?
When data has been requested
by a DBMS, to which of the
following areas does the
operating system deliver the
requested data from the
Which of the following items
is/are contained in a DDL?
To a system work
To a system work
To the user work
To system buffer
and 2
A schema data definition
language (DDL) entry
includes references to a
physical device or media
After the database physical
description has been
examined, which of the
following items keys the
actual physical record to be
The data manipulation
language relies on which of
the following language types
to provide the procedural
capabilities required to
manipulate data?
After the operating system
has transferred data to the
system buffer area, where
does the DBMS deliver the
data to be used by a source
DML only
Host language only
DML and the host
When selecting a DBMS, the
primary consideration should
be to select a technology
that will meet which of the
following criteria?
When a DBMS is selected for
a microcomputer system,
which of the following
is/are (an) important
Be the lowest cost
Be the easiest to use
Require the shortest
implementation time
Support the long-term
DBMS needs
Capability of receiving
downloaded data
Ability to be used on a
Ability to enable quick
and easy screen formats
All of the above
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