Burroughs MT983, MT993 Display Terminals Reference Manual

 Burroughs >)
MT 983/MT 993
Display Terminals
REFERENCE MANUAL
PRICED ITEM Revised 1-15-81 by
N -
“The names used in this publication are not of individuals living or
otherwise. Any similarity or likeness of the names used in this publi-
cation with the names of any individuals, living or otherwise, is purely
coincidental and not intentional.”
Burroughs believes that the information described in this
manual is accurate and reliable, and much care has been
taken in its preparation. However, no responsibility, financial
or otherwise, is accepted for any consequences arising out of
the use of this material. The information contained herein is
subject to change. Revisions may be issued to advise of such
changes and/or additions.
Warning: This equipment generates, uses, and can radiate radio frequency energy
and if not installed and used in accordance with the instructions manual, may cause
interference to radio communications. As temporarily permitted by regulation it
has not been tested for compliance with the limits for Class A computing devices
pursuant to Subpart J of Part 15 of FCC Rules, which are designed to provide reasonable
protection against such interference. Operation of this equipment in a residential
area is likely to cause interference, in which case the user at his own expense will be
required to take whatever measures may be required to correct the interference.
This edition includes the information released under the following:
PCN 1118361-001 (January 15, 1981)
Any comments or suggestions regarding this publication should be forwarded to Systems Documentation, Technical
Information Organization, TIO-East, Burroughs Corporation, P.O. Box CB7, Malvern, Pennsylvania 19355.
Section
1
Title
GENERAL INFORMATION
General Description
CRT Display
Keyboard
Peripheral Options
Interface Capabilities
System Configuration
System Characteristics
Capabilities and Features
Capabilities
Functional Modes
Operating States
Features
Page Formatting
Configuration Control
Status Display Line
Negative Video
Cursor Display
Highlighting
Edit Functions
Operator Controls and Functions
Display Monitor Controls
Keyboard Controls
SYSTEM CONCEPTS
General
Memory Allocation
Firmware Memory
Host System Accessible Memory
Major Processes
Main Process
Local State Operation
Receive State Operation
Transmit State Operation
Keystroke Interpreter
Message Interpreter
Data Comm Buffer
Message Synthesizer
Data Comm Interface Process
(Transceiver)
Transceiver/Main Process
Interface
Keyboard Interface Process
Display Store Process
Video Process
Functional Modes
Forms Mode
Keyboard/Data Comm
Differences
Entry Into Forms Mode
Exit from Forms Mode
Configuration Mode
Scratchpad Memory
Page
1-1
1-1
1-2
1-2
1-2
1-3
1-3
1-3
14
14
14
1-6
1-6
1-7
1-7
1-7
1-8
1-8
1-8
19
1-14
1-14
1-14
2-1
2-1
2-1
2-1
2-1
2-2
2-2
2-2
2-2
2-3
2-5
2-5
2-5
2-7
2-8
29
29
2-10
2-10
2-10
2-10
2-11
2-11
2-11
2-11
Default Terminal Configuration 2-12
Section
MT 983/MT 993 Terminal Systems
TABLE OF CONTENTS
Title Page
Terminal Password 2-12
Maintenance Functions 2-12
Confidence Test 2-12
Status Line Error Messages 2-13
Error Log 2-13
DATA COMMUNICATIONS
INTERFACE 2.1
General 3-1
Control Character Sequences 3-1
Illegal Characters 3.1
Data Error Checking 3-1
Terminal Address 3-1
Transmission Number 3-1
Communication Procedures 3-2
Poll (POL) 3-2
Group Poll (GPL) 3-2
Select (SEL) 3-2
Fast Select (FSL) 3-2
Broadcast Select (BSL) 3-2
Contention (CON) 2
Communications Interface 3-2
Two-Wire Direct Interface (TDI)
Communications 3-3
Burroughs Direct Asynchronous
Access (BDAA) Interface 3-3
Concatenation Cables 34
Asynchronous Data
Communication 34
Synchronous Data Communication 34
SERIAL 1/0 INTERFACE 4.1
General 4-1
Interface Controls 4-1
Invitation to Interrupt -1
Device Select 4-1
GET Instructions 4-1
Get IStatus 4-2
Get DStatus (Device Status) 4-2
Get Data 2
Send Instruction 4-2
Send Data 4-2
Send Device Command 4.2
KEYBOARD 5-1
General Description Sl
Functional Characteristics 5-1
Keyboard Code Output 5-1
Code Buffer 5-1
N-Key Rollover 5-1
Security Keylock 5-1
Automatic Key Repeat Function 5-2
TP 110 Keyboard 5.2
TP 119 Keyboard 54
MICRO-DISK FILE STORAGE
DEVICES 6:
pubs
pardos
[ro
MT 983/MT 993 Terminal Systems
Section
iv
TABLE
Title
General Description
Diskette Organization
Data Formatting
Applicable Documentation
PRINTERS
General Description
Printer Features
Print Field Density
Print Speed
Bidirectional Printing
Forms Handler
Vertical Line Spacing
Variable Page Length
Out-of-Paper Detection
Print Characters
Printer Status
Printer Controls
Keyboard Printer Controls
Data Comm Printer Controls
Printing Screen Data
OF CONTENTS (CONT)
Page
6-1
6-1
6-1
6-2
7-1
7-1
7-2
7-2
7-2
7-2
7-2
7-2
7-2
7-2
7-3
7-3
7-3
7-3
7-3
7-3
Section
Title
Controlling Print Operation from
the Host System
TERMINAL CONFIGURATION
General
Scratchpad Memory Display
Entering Configuration Data from
Keyboard
Entering Configuration Data from
Host System (Data Comm)
ESC RT Sequence
ESC RH Sequence
ESC RC Sequence
ESC RP Sequence
LOCAL KEYBOARD CONTROL
(CTRL) SEQUENCES
General
DATA COMM CONTROL
Page
7-4
A-1
А-1
А-1
А-2
А-6
А-7
A-7
A-8
A-8
B-1
B-1
CHARACTERS AND SEQUENCES C-1
General
REFERENCE DATA
INDEX
C-1
D-1
1
Figure
1-1
1-2
1-3
1-5
5-1
Table
1-1
1-2
2-1
3-1
5-1
MT 983/MT 993 Terminal Systems
LIST OF ILLUSTRATIONS
Title Page
MT 983 Display Terminal 1-1
MT 993 Display Terminal 1-2
MT 983/MT 993 System
Configuration 1-3
Sample of a Forms Mode Page 1-5
Display Monitor Controls 1-14
Major Processes of Terminal 2-3
Main Processor Operation, Flow
Diagram 24
Typical Display Memory
Organization 2-9
Error Log Format 2-14
TP 110 Alphanumeric Keyboard 5-2
LIST OF TABLES
Title Page
MT 983/MT 993 Characteristics 1-3
Keyboard Controls 1-15
MT 983/MT 993 Memory
Allocation 2-1
Communications Interface
Characteristics 3-3
Communications Interface
Connector Assignments 3-5
Summary of TP 110 and TP 119
Keyboard Edit and Function Keys
and Indicators 5-3
Figure
5-2
6-1
6-2
7-1
A-1
A-2
D-2
D-3
D4
Table
A-1
A-2
A-3
A4
B-1
C-1
C-2
Title
TP 119 Keyboard
TP 420 File Storage Module
Diskette Storage Medium
TP 313 Journal Printer
Display Format of Configuration
Area of Scratchpad Memory
Interpretation for a Typical
Scratchpad Memory Byte
Standard U.S. ASCII Chart
Decimal to Hexadecimal Conver-
sion Chart
Special Symbols Chart
Page
54
6-1
6-2
7-1
A-1
A-2
D-1
D-2
D-3
Programmable Cursor Select Values D4
Title
Terminal Configuration from
Keyboard
Terminal Configuration
Parameters
Baud Rate Conversion
Clear-to-Send Delay
Keyboard Control Sequences
Data Comm Control Characters
Description of Data Comm Escape
Control Sequence
Page
A-2
А-З
А-7
А-7
B4
C-1
C-2
MT 983/MT 993 Terminal Systems
| Section 1
SECTION 1
GENERAL INFORMATION
GENERAL DESCRIPTION
The MT 983 and MT 993 units are microprocessor-based modular terminal systems designed for general-pur-
pose input and display applications. The MT 983 terminal consists of a free-standing, self-contained, cathode
ray tube (CRT) display monitor and a keyboard. (The MT 983 is shown in figure 1-1.) The MT 993 terminal
(figure 1-2) differs from the MT 983 only in its physical screen size and physical packaging. The MT 993
monitor has 9-inch (diameter) screen; whereas, the MT 983 monitor has a 12-inch screen. The MT 993 display
monitor is packaged separately from the logic control circuits which are housed in a separate cabinet. MT 983
logic circuits are housed in the display monitor cabinet. Unless otherwise stated, the information in this manual
applies to both models.
DISPLAY
MONITOR
В
KEYBOARD
EP1760
Figure 1-1. MT 983 Display Terminal
1-1
MT 983/MT 993 Terminal Systems
Section |
LOGIC
CONTROL
UNIT
DISPLAY
MONITOR
KEYBOARD
EP1761
Figure 1-2. MT 993 Display Terminal
CRT Display
The CRT provides a green phosphor high-persistence display of fully formed characters. Each character is
made up с? small segments as opposed to solid line strokes. The MT 983/MT 993 can display up to 25 lines
of information on the screen at one time: 24ilines of display data and one status line (25th line). Each line has
a maximum length of 80 characters. The format of display data is alterable to 24 lines of double-width charac-
ters with each line having a maximum length of 40 characters. In this case, the 25th line (status line) is still
displayed :n standard character size format (80 characters in length).
Keyboard
The keyboard is used by the operator to enter information into the terminal. There are several types of key-
boards which may be used. These are identified and described in Section 5 of this manual.
Peripheral Options
Optional peripheral devices may be used with either terminal system. These include auxiliary output printers,
micro-disk file storage devices, and magnetic card readers. Specific information concerning the models and
functions of the printers and micro-disk is contained in Sections 6 and 7.
1-2
MT 983/MT 993 Terminal Systems
Section 1
interface Capabilities
The terminal can exchange data with both local and remote devices. Data interchange (data communications
interface) with a remote device (host system) such as a central computer system uses the ASCII transmission
code.
The data communication interface can be performed using either the Burroughs asynchronous or the synchro-
nous method of transmission. More detailed information is given in Section 3.
Data 1s exchanged with local devices such as keyboards and peripherals using a serial I/O interface. More de-
tailed information concerning this is in Section 4.
SYSTEM CONFIGURATION
The basic system configuration for the MT 983/MT 993 is shown in figure 1-3.
BURROUGHS
SYNCHRONOUS OR ASYNCHRONOUS
DATA COMMUNICATIONS
KEYBOARD
MT 983/993
OPTIONAL OPTIONAL
FILE STORAGE JOURNAL
UNIT OPTIONAL PRINTER
MAGNETIC —J
CARD READER
EP1762
Figure 1-3. MT 983/MT 993 System Configuration
SYSTEM CHARACTERISTICS
The characteristics of the MT 983/MT 993 terminal system are given in table 1-1.
Table 1-1. MT 983/MT 993 Characteristics
Item Characteristic
MT 983 Dimensions (without 15.0 inches (38 cm) high; 16 inches (40.6 cm) wide; 13.0 inches (33 cm) deep
keyboard)
MT 993 Dimensions (without
keyboard)
Monitor I'l inches (28 cm) high; 8 inches (20 cm) wide: 11 inches (28 cm) decp
Logic Control Unit 7.5 inches (19 cm) high: 13.5 inches (34.3 cm) wide; 5.5 inches (14 cm) deep
MT 983/MT 993 Terminal Systems
Section 1
(continued)
Item
Weight (without keyboard)
MT 983
MT 993
Monitor
Logic Control Unit
Display screen
Display color
Display screen capacity
Display data format
Display character format
Character generator
Character code
Data transfer rates
Display memory
Data comm buffer
Status line
Display refresh rate
Input voltage range
Heat generated
Relative humidity range
Operating environment
Table 1-1. MT 983/MT 993 Characteristics
Characteristic
35 pounds (15.9 kilograms)
8 pounds (3.6 kg.)
11 pounds (5 kg.)
Cathode ray tube ( CRT)
Green characters on dark background (normal video); dark characters on green background
(negative video)
Up to 1.920 characters, plus an 80-character status line (25th line)
24 lines with standard 80 or double-width 40 characters per line
fully formed characters in an 8 x 16 character image area or 16 x 16 (double-width) character
image area
Up to 128 characters (upper and lower case alphanumeric characters and special symbols)
US ASCII or international
up to 1800 bps EIA RS232C asynchronous
up to 9600 bsp EIA RS232C synchronous
Up to 9.600 bps TDI (1000 ft. maximum distance)
Up to 38.400 bps BDAA (15.000 ft. maximum distance)
2.000 (optional 4.000) characters
up to 2000 characters with optional 4000 character display memory (configurable)
80 characters. displayed as the 25th line
60 or 50 Hz (input line frequency)
100 to 240 volts ac to 50 or 60 Hz
500 BTU/hour
10 to 90 percent
40 to 122 degrees F (5 to 50 degrees C)
CAPABILITIES AND FEATURES
Various capabilities and features have been incorporated into the terminal to enable the terminal to function
as a general purpose input and display system. These capabilities and features are described separately in the
following subparagraphs.
Capabilities
The terminal is capable of being operated in three different functional modes and three separate operational
states. The functional mode determines the behavior of the terminal in response to various operator and host
system initiated actions; whereas. the operating state determines the interface operation of the terminal.
Functional Modes
The terminal may be in one of following three functional modes at any given time:
Forms mode
Non-forms mode
Configuration mode
The forms mode and non-forms mode are considered to be operational modes. The configuration mode 1s a
non-operational mode and is only used to set up or alter the terminal configuration. The use of the configura-
tion mode is not considered to be a normal operator function. A description of this mode is contained in Sec-
tion 2.
1-4
MT 983/MT 993 Terminal Systems
Section 1
Forms Mode
Forms mode operations can be entered from the keyboard or from the host system. In the forms mode, the
terminal protects part of a page from being changed (either by the operator or by the host system). The forms
page is divided into two types of fields: protected fields and unprotected fields. When a page is displayed on
the screen in the forms mode, the operator can enter data in the unprotected fields but is prohibited from
altering the protected fields. However, both unprotected fields and protected fields are transmittable.
Delimiters are used to define the beginning and end of the unprotected fields. Any two symbols (one for be-
ginning and one for end) may be setup to represent keyboard entered delimiters (configuration selectable).
However, the symbols used to represent the delimiters displayed on the screen when the terminal is in forms
mode or when the delimiters are transmitted are fixed.
A forms-mode page must have at least one unprotected field. Therefore, before the terminal designates a page
as being in forms mode, it examines the page to determine whether it contains an unprotected field. Further-
more, once a page has been designated as a forms page, the terminal ensures that it continues to meet this
criteria by prohibiting any operation that would either over-write a delimiter in the page or store a delimiter
Into a page. (Were it not for this prohibition, the operator or host system could fill an unprotected field with
delimiters, resulting in no unprotected space.)
The fixed delimiters used to signify the beginning of an unprotected field are the US delimiter (graphic symbol
>>) or the GS delimiter (graphic symbol A). The US delimiter signifies that the unprotected field is a normal
left-justified field; whereas, a GS delimiter signifies a right-justified unprotected field. The fixed delimiter used
to signify the beginning of a protected field (end of an unprotected field) is the RS delimiter (graphic symbol
<1) (See figure 1-4.)
PROTECTED > UNPROTECTED < PROTECTED . . .
ee PROTECTED . . . /\ UNPROTECTED . . .
. . UNPROTECTED. . . {> UNPROTECTED. . . .
—]]
. + . <I PROTECTED [> unPROTECTED G... PROTECTED
..DDD AIDA ..............
о я что ва ве вв те ан ие ва вы ван + ва + a
в в #* % E E E 8 тя в аа вп в пива ев т в + = ве =
FORMS—MODE PAGE
EP1763
Figure 1-4. Sample of a Forms Mode Page
The forms delimiters are always protected, as are any characters between the beginning of the page and the
first delimiter. The actual unprotected fields, therefore, consist of the characters between each GS/US delimiter
and the next delimiter (or the end of the page, if a GS or a US is the last delimiter on the page). Neither
protected nor unprotected fields are limited by the beginning or the end of a line. Fields may begin on one
line and continue on subsequent lines.
1-5
MT 983/MT 993 Terminal Systems
Section |
Non-Forms Mode
The non-forms mode is the default mode when the terminal is not in forms mode or configuration mode. In
the non-forms mode, data can be entered or altered by the keyboard operator or host system in the conven-
tional methods as described in the remainder of this section.
Operating States
The system can be in one of the three operating states:
Local
Receive
Transmit
These operating states are selectable from the keyboard.
Local State
In the local state, the terminal accepts data entered from the keyboard or the optional peripherals or may out-
put data to an optional peripheral. While in the local state, the host system cannot gain access to the display
data. However, the host system can force the terminal into the receive state or transmit state through a Fast
Select. Group Select, or Broadcast Select data comm operation for the purpose of sending or retrieving display
data. The terminal will sound an alarm to signify a request from the host system for access to the terminal,
There are two substates which operate in the local state: control and character insert. The control substate
is entered into from the keyboard by way of the CTRL key. This substate extends the keyboard commands
available to the operator. When in the control substate, the terminal interprets the keyboard data entered as
specific commands (refer to subparagraph titled Keyboard Controls in this section). The character insert sub-
state is entered when the character insert key is activated. For a description of the operation of the terminal
in this substate, refer to the subparagraph titled Character Insert by Line or Page in this section.
Receive State
The receive state is entered into locally from the keyboard by the RCV key or remotely from the host system
through a Fast Select, Group Select, or Broadcast Select data comm operation. In this state, the terminal ac-
cepts data messages from the host system. No action is taken by the terminal on an incoming message until
the message is received in it’s entirety and message parity is checked. The host system can send control mes-
sages or display data messages.
Transmit State
The transmit state is entered into locally from the keyboard by the XMT key or remotely from the host system
through a special control character sequence which may be contained in the received data. In this state, the
terminal waits to be polled unless the the terminal is in the Contention mode of data communications interface;
in which case. the terminal sends a transmit request to the host system. When the terminal is polled or the
host system acknowledges the transmit request, the terminal proceeds to transmit the contents of the display
screen from the cursor location to the first ETX (end-of-text) character. If no ETX character is present on
the screen, then the contents of the display screen from the home position to the cursor location are trans-
mitted.
Features
Following is a list of features of the terminal:
Page formatting
Configuration control
Status display line
1-6
MT 983/MT 993 Terminal Systems
Section 1
Negative video
Highlighting
Cursor display
Editing
Data communications
Storing and retrieving data from an optional storage unit
Sending data to an optional auxiliary printer
The following subparagraphs describe the various features of the terminal. The operation of many of these
features is dependent upon the configuration of the terminal. The configuration of the terminals is changeable
by the user. Refer to Section 2 for detailed information concerning terminal configuration.
Page Formatting
The terminal allows for the formatting of display data (either by the operator or host system) into pages. If
specific page boundaries are not specified, the entire contents of the display memory are considered one page.
In regard to page formatting, it is essential that a distinction be made between the terms “page” and “screen
window.” A page is a group of contiguous lines of data grouped together for storage. The term “screen win-
dow” refers to the lines (not including the status line) visible to the operator. The screen window may contain
several pages, exactly one page, or a portion of a page.
Configuration Control
The terminal contains stored data which programs the terminal configuration. This data can be changed from
the keyboard when the terminal is in the configuration mode. Configuration data can also be changed from
the host system through the use of data communications interface control characters. Section 2 of this manual
provides more detailed information on terminal configuration.
Status Display Line
The status line displays information to the operator which indicates existing or previous error conditions, spe-
cial messages from the host system, and page number of the cursor page. The status line is also used to indi-
cate when the terminal is in the control (CTRL) substate. The status line is not accessible to the operator.
The status line is divided into the following parts:
Error messages (columns 1-16)
Special messages (17-73)
Page number (74-80)
Error Messages
The terminal displays error messages in the first 16 character positions of the status line. The terminal can
display the following error messages:
Error Message Error Condition
DATA COMM ERROR Block check or data comm hardware error
KEYBD DATA LOST Keyboard buffer overflow
PRINTER ERROR Printer hardware error
(Power off or faulty cable connection)
RECEIVE ERROR Error condition detected during receive operation
Special Messages
The special message section of the status line is used to display data comm entered data that cannot be altered
by the operator. Special messages of up to 57 characters may be displayed when the terminal is not in the
1-7
MT 983/MT 993 Terminal Systems
Section 1
control (CTRL) substate. When the terminal is in this substate, special messages of up to 52 characters may
be displayed. Character positions 69 through 73 are reserved for display of the control substate indicator
(CTRL). Typical special messages may include computer or system status and operator notification of data
entry on non-displayed pages.
Page Number
The word PAGE and the number of the page on which the cursor is located appear automatically in the last
seven positions of the status line.
Negative Video
The terminal has the feature of negative video. The video presentation is under the control of the operator
via the keyboard, and the host system via the data communications interface. The display is in normal video
(green characters on a dark background) when power is turned on. The display can be changed to negative
video (dark characters on a green background) or back to normal video:
|. From the keyboard through the use of a control (CTRL) code. (Refer to table 1-2.)
2. From the host system through the use of data communications control characters. (Refer to Appendix
C.)
Cursor Display
The terminal generates a visual cursor which indicates where data entered from the keyboard will appear. The
cursor is displayed as the reverse image of the character at the cursor location.
The cursor position is stored in a cursor counter and not in display memory. As each character is loaded into
the display memory from the keyboard. the cursor is advanced one position to the right. When the end-of-
line is reached. the cursor is advanced to the first position of the next line.
The cursor may be configured for blinking or non-blinking operation. The cursor can be positioned remotely
from the host system. The position of the cursor can be transmitted to the host system. |
Highlighting
Highlighting can be used to emphasize specific blocks of data (up toone line long) or arcas of the screen. High-
lighting can be enabled by the operator via the keyboard (refer to table 1-2) or by the host system. The entered
highlighting information is automatically included in the display data when it is stored in memory or-trans-
mitted to the host system. During on-line operations with a host system, highlighting is enabled by receiving
one or more of the highlighting control characters within the text of a data comm message (refer to Appendix
C).
Highlighting functions may be grouped to produce more than one highlight on a given line or field (forms
mode) of data. This requires the entry of successive highlight control characters on the cursor line. Each en-
tered highlight control character occupies a separate location in display memory. The highlighting functrons
recognized by the terminal are:
Underline
Blink
Secure
Bright
Reverse Video
Highlight control characters are stored in memory but are not displayed. A highlight control character occupies
one space in display memory and is displayed on the screen as a blank. The applicable highlight starts at the
highlight character and extends over the following characters to the right. up to and including the next RS
delimiter. If no RS delimiter is present. the highlight extends to the end of the line. The highlight may not
extend beyond the end of the display line. Note that the presence of two reverse highlight control characters
1-8
MT 983/MT 993 Terminal Systems
Section 1
in the same line or field do not cancel out each other. In this case, the second reverse highlight control charac-
ter has no effect, provided that no RS delimiters are encountered between the two reverse highlight control
characters. If the terminal is in negative video operation, the effects of highlighting are reversed.
In the forms mode, highlights can be displayed in both protected and unprotected areas; however, they may
not extend beyond the RS delimiter. When in the forms mode, highlighting can be initiated from the keyboard
only in the unprotected areas.
Underline Video
The underline highlight enables the underlining of a designated character or field. When an underline highlight
control code is detected, the display begins to underline and continues this highlight until an RS delimiter is
detected or until the end of the line, whichever occurs first. The underline consists of solid video which is
in contrast to the background video.
Blink
The blink highlight enables blinking of a designated character or field. When a blink highlight character is de-
tected, the characters immediately following the highlight character (displayed as a blank) and up to the RS
delimiter or end-of-line (whichever occurs first) blink at a 1.3 Hz rate.
Secure
The secure highlight allows data such as security codes to be entered in memory but not displayed on the
screen. The secure highlight fills in the character position immediately following the highlight character and
all the remaining characters in the line or up to the next RS delimiter (whichever occurs first) with solid video:
green when in normal video operation and dark (non-video) when in the negative video operation.
Bright Video
The bright video highlight causes brighter characters to appear when the display is in normal video operation.
In negative video operation, this highlight causes a brighter background to appear.
Reverse Video
This highlight causes reverse video from the highlight character position until an RS delimiter is detected or
the end of line is reached (whichever occurs first).
This highlight causes negative video to be displayed in the highlight boundaries if the display is in normal video
operation. Activation of the reverse video highlight when the display is in negative video operation causes nor-
mal video to be displayed in the highlight boundaries.
Edit Functions
The edit functions provided by the terminal are described in the following subparagraphs. Most of these func-
tions may be invoked remotely from a host system by means of data communications control characters, or
locally from the keyboard. The data comm control codes used to invoke the various edit functions from a
host svstem are contained in Appendix C. The keyboard controls are described in this section under the head-
ing “Operator Controls and Functions”.
Character Insert by Line or Page
The terminal has the capability of two types of character insert functions: by line or by page.
Pressing the character insert key puts the terminal in a character insert condition and initiates a character in-
sert by line operation. The terminal automatically inserts a single space at the cursor position. Subsequent
pressing of any non-contro! key (alphanumeric character key or punctuation key: including space) causes the
applicable character to be inserted at the cursor location. The succeeding characters within the line are moved
one space to the right. Surplus characters, if any. are shifted off the end of the line znd lost.
1-9
MT 983/MT 993 Terminal Systems
Section |
Pressing the character insert key when the terminal is in the contrel (CTRL) substate also puts the terminal
in a character insert condition; however, the function is performed on a page basis. The succeeding characters
are moved one space to the right and down line by line through the page. A second pressing of the character
insert key disables the character insert condition.
When in forms mode. the character insert function causes data shifting within the single unprotected data field
in which the cursor 1s located.
The terminal can also perform the character insert function through host system control. However, the data
communications character insert function differs from the keyboard control function. The character insert con-
dition is not entered. Instead, each character to be inserted requires a new character insert data communica-
tions control code.
Character Delete by Line or Page
The character delete key causes the erasure of the displayed character at the cursor location. The succeeding
characters within the line move one space to the left. Putting the terminal in the control (CTRL) substate prior
to pressing the character delete key, performs the character delete operation on a page basis. The succeeding
characters down on the page are moved one space to the left and up line by line.
In forms mode. the character delete function causes data shifting within the unprotected data field in which
the cursor is located. If the cursor is in a protected field, character deletion is prohibited. From the keyboard,
the character delete operation in a US unprotected field is different than in a GS unprotected field. In a US
field. the character is deleted and the succeeding characters in the field are shifted one space to the left. In
a GS field. the entire field is shifted to the right, provided the cursor is at the rightmost position in the field.
The terminal also performs the character delete functions through host system data communications control.
From host system control. the character delete operation in a GS field is the same as in an US field.
Line Insert/Delete
The terminal can insert and delete lines. The line insert function moves all data in the page below the cursor
line (including the line with the cursor) down one line.
Line delete erases the line in which the cursor is positioned and all data in the page below the cursor line
moves up one line.
This function is inhibited in forms mode.
Line Movement Up/Down
The line movement function causes a line of display data to be interchanged with the line immediately above
or below, depending on the specific function selected. The line of data to be moved is selected by placing
the cursor in that line. When line movement causes data to be displaced, the displaced data reappears in the
original position of the line moved. The cursor follows the moved line in all cases. An upward movement of
the top line of a page causes the bottom line of the page to be exchanged with the top line of the page. The
same exchange occurs if a downward movement is requested for the bottom line of a page. This function is
inhibited during forms mode.
Clear Page
This function may be invoked from the keyboard or from the host system. In the non-forms mode, the clear
page operation fills the entire page with blanks and returns the cursor to the home position.
If the terminal is in forms mode, either the entire page may be cleared from the keyboard or only the unpro-
tected fields may be cleared, depending on the configuration option invoked. If the entire page is cleared, the
termina! is put into the non-forms mode. When in the forms mode and the clear page operation is invoked
from the host system, only the unprotected fields are cleared. In all cases of forms mode operation, the cursor
(pointer) is left in the data entry position of the first unprotected field of the page.
1-10
MT 983/MT 993 Terminal Systems
Section 1
Clear to End-of-Line/Page
This operation clears data from the cursor position to the end of a line or page. In the non-forms mode, the
clear end-of-line operation clears all data from the cursor position to the end of a line. In forms mode, this
operation clears all data from the cursor position to the RS delimiter.
The clear end-of-page operation clears all data from the cursor position to the end of the page.
The terminal is also capable of initiating the clear to end-of-line/page function through host system control.
Lower Case Enable/Disable
It is possible, through keyboard or host system control, to enable/disable the display of lower case letters.
When the lower case is disabled, all letters are displayed in upper case. Note that keyboard control disables
only keyboard-entered lower case. Host system control disables only data comm entered lower case charac-
ters.
Roll Page Up/Down
The purpose of this function is to enable the operator to roll the contents of the page through the screen win-
dow. The roll page up function shifts the entire page up one line while the cursor remains stationary. The
top line of the page becomes the bottom line. In the roll page down operation, movement is reversed. This
function is inhibited in forms mode. This function can be invoked from the keyboard or by the host system.
Scroll Display Data Up/Down
The purpose of this function is to enable the operator to scroll the entire contents of the display memory
through the screen window. This function can only be invoked from the keyboard. In this function, the cursor
remains stationary while the display memory data is moved line-for-line up or down the screen. During a scroll
up operation, the top line of the screen disappears from view and the bottom line is filled from memory with
the next display data line. When the last line of the display memory is shown at the bottom of the screen,
all further scroll up operations are ignored. Scroll down operation is the reverse of scroll up.
If the scroll operation causes a new page to appear on the screen, the page number located on the status line
Is changed accordingly. If the new page is a forms protected page, the FORMS indicator lights and the terminal
is put in forms mode when the first line of the forms protected page appears at the top of the screen. If the
operator tries to alter the data on that page, the limitations of a forms protected page apply (only unprotected
fields may be altered).
Page Advance/Back
The page advance function, when invoked from the keyboard, displays the next page with the cursor in the
home position of that page. If the new page is a forms protected page, the FORMS indicator lights and the
terminal enters forms mode; the home position of the cursor is the home position of the first unprotected field
(left-most position of a US field and right-most position of a GS field).
When this function is invoked from the host system, the specified page is displayed on the screen. If the
specified page is in the forms mode, the cursor (pointer) is placed at the beginning of the first unprotected
field.
In either case, if the last line of the new page appears above the last line of the screen. the display is adjusted
so that the last line of the page appears at the last line of the screen. As a result. the first line of the page
may not be at the top of the screen.
Move Cursor (Pointer) Up/Down
This function moves the cursor (pointer) vertically to the line directly above or below its initial position. If
the cursor is initially at the top line of the page and a move cursor up function is invoked, the cursor moves
1-11
MT 983/MT 993 Terminal Systems
Section 1
to the same column in the bottom line of the page. if the bottom line of the page was not previously in the
screen window. the screen window is automatically rolled through the page until the last line of the page is
displayed. This function can be invoked from either the keyboard or the host system.
Move Cursor (Pointer) Left/Right
This function moves the cursor (pointer) horizontally one character position to the left or right. If the cursor
is initially at the last character on the last line of the page and a move cursor right function 1s invoked. the
cursor moves diagonally to the first character position on the first line of the page. The reverse is true for
the move cursor left operation when the cursor is at the first position of the top line. When changing lines
would put the cursor out of the screen window (page is larger than the screen). the page is advanced through
the screen window to keep the cursor in view.
Position Cursor (Pointer)
This function moves the cursor (pointer) directly to the row and column position of the page as specified in
the parameters of the command. This function can be invoked from either the keyboard or host system. If
either the row or column value specified by the parameters is out of range for the current line and page size.
the operation is inhibited.
Align Cursor to Pointer
When this function is invoked. the cursor moves directly to the current position of the data comm pointer
if the cursor and data comm pointer are located on the same page. If. during the operation. the cursor leaves
the screen window, the page automatically rolls through the window to the extent necessary to bring the cursor
back onto the screen.
Set Mobile Home Pointer
This function is used to specify a start-of-transmission point. This function can be invoked from either the
keyboard or the host system. The location of the cursor during keyboard operations or the data comm pointer
during host system operations establishes the row and column position of this point.
Cursor Tabulation
This function provides a means of rapid cursor movement both horizontally (across the cursor line) and verti-
cally (upward or downward in the cursor column). In this function. the cursor will proceed to the next tab
stop. Horizontal tab stops can be fixed or variable.
Setting and Clearing Horizontal Tab Stop
If the terminal is configured for the variable tab stop option. individual tab stops can be set from either the
keyboard or the host system. The current column location of the cursor is set as a tab stop upon receipt of
the valid command from the keyboard or host system. All variable tab stops can be cleared by use of a single
keyboard or host system command.
If the terminal is configured for the fixed tab stop option. tab stops are invoked every eight columns starting
at column 1 (I. 9. 17. and so on).
Horizontal Tab Forward Function
This function can be invoked from either the keyboard or the host system. When this function is invoked.
the cursor moves to the next tab stop (non-forms mode) or to the first character position of the next unpro-
tected field (forms mode). An HT character is written into the new cursor location in memory. The tab symbol
is displayed if the tab function is invoked by use of the TAB key on the keyboard or from the host system
and the terminal is configured for this feature. If the terminal is not so configured. or if the tab function 1s
invoked by use of the SKIP key on the keyboard. nothing is stored in memory and no tab page symbol 1s
displayed. If no tab stops have been set. the cursor is left at the home position of the page.
1-12
MT 983/MT 993 Terminal Systems
Section 1
If the terminal is in the forms mode and the next unprotected field is a GS field, the cursor continues to the
rightmost position of the field. However, if the terminal is configured for the HT character as described above,
the HT character is written into the leftmost position of the field even though the cursor is positioned at the
rightmost position of the GS field.
Horizontal Tab Reverse Function
This function can only be invoked from the keyboard. In non-forms mode, the cursor is moved left to the
previous tab stop, or to the home position if no tab stops are set. If the terminal is in the forms mode, the
cursor moves left to the previous field and stops at the leftmost position of a US field and the rightmost posi-
tion of a GS field.
Vertical Tabulation
The terminal can be configured for vertical tab stops at lines 1, 9, and 17. The vertical tab down function
can be invoked from the keyboard or from the host system. The vertical tab down function moves the cursor
down to the next vertical tab stop. If the initial cursor position is the last tab stop (line 17), it moves to the
first line of the page. The reverse is true if the cursor is initially at the first line of the page and a vertical
tab up function is invoked. The vertical tab up function can only be invoked from the keyboard. In all cases,
the cursor 1s left at the first character position of the new line.
Carriage Return Function
When the terminal 1s in the non-forms mode, the carriage return function may or may not write the carriage
return character in memory and display such at the initial cursor (pointer) position (depending on the terminal
configuration). Also depending on terminal configuration, the carriage return function either returns the cursor
(pointer) to the first character position in the current or next line. (If the cursor is initially at the last line
of the page, the first line of the page is the next line.) The page automatically rolls through the screen window
to keep the cursor in view.
When the terminal is in forms mode, the operation of the carriage return function is the same as in the non-
forms mode except that the cursor is moved to the next unprotected field of the page (keyboard operations
only). A data comm invoked carriage return function in the forms mode does not automatically skip the data
comm pointer to the next unprotected field.
End-of-Text (ETX) Function
The ETX or end-of-text function can be invoked either from the keyboard or from the host system. The
operation of the ETX function differs depending upon whether the function is invoked from the keyboard or
the host system.
In a keyboard ETX operation, an ETX character is stored at the cursor location unless the cursor is in a pro-
tected area of a forms page. (The ETX function has no effect if the cursor is in a protected area of a forms
page.) Depending on the terminal configuration, the cursor either returns to the first character position of the
current line or to the ‘‘mobile home pointer’’location. (If necessary, the page is automatically rolled through
the screen window to keep the cursor in view.)
In a host system (data comm) invoked ETX operation (an ETX character occurs exactly once in each incoming
data message), the ETX character is stored at the current location of the data comm pointer (non-forms mode)
provided the terminal is so configured. If the terminal is configured to store the ETX character, the data comm
pointer moves one space to the right. if the data comm pointer is located on the same page as the cursor,
the two are aligned with one another.
Search Function
The search function makes it possible to designate a ‘search character’’ and to tab the cursor through display
memory stopping at each occurance of the “search character”. The SKIP key on the keyboard 1s used for
this function.
1-13
MT 983/MT 993 Terminal Systems
Section |
OPERATOR CONTROLS AND FUNCTIONS
Operator controls and functions are of two types: display monitor controls and keyboard controls.
Display Monitor Controls
Display monitor controls (figure 1-5) consist of an ON-OFF switch and the BRIGHTNESS control. On the
MT 983 the ON-OFF switch and BRIGHTNESS control are located on the front of the monitor below the
CRT.
On the MT 993. the BRIGHTNESS control is on the upper right front corner of the monitor cabinet and the
ON-OFF switch is on the logic control unit. The functions of these controls are:
ON-OFF Switch. The ON-OFF switch provides the control for activating the terminal with ac line volt-
age.
BRIGHTNESS Control. The BRIGHTNESS control is used to adjust the display intensity for optimum
viewing level.
Keyboard Controls
Keyboard controls are used by the operator to invoke the various functions and features of the terminal.
(Many functions and features of the terminal are dependent on terminal configuration; refer to Section 2.) Ta-
ble 1-2 lists the various functions and the associated keyboard controls. The specific key mnuemonic used for
each keyboard control is dependent on the model keyboard used with the terminal. Refer to Section 5 for
detailed information on these keyboards.
BRIGHTNESS
CONTROL
MT 993
© MT 983
BRIGHTNESS ON-OFF
CONTROL SWITCH
EP1764
Figure 1-5. Display Monitor Controls
1-14
MT 983/MT 993 Terminal Systems
Section 1
Table 1-2. Keyboard Controls
1. This table is intended as a quick reference to the commonly
used keyboard controls needed to operate the terminal. A
brief description of the action caused by the keyboard
controls in the non-forms mode is given. For a description
of the actions caused by the keyboard controls when in the
forms mode, refer to the subparagraphs in this section
describing the specific control functions.
2. Parentheses are used to indicate actual key names.
Keyboard
Function Controls Action
SELECT FUNCTIONS:
Control Function (CTRL) Press key once to activate control function. Pressing the key a second time, or
pressing one or more keyboard keys, deactivates this function. To lock
terminal in control function for an extended period, use shifted (CTRL)
key. In this case, control function can be deactivated by pressing (CTRL).
When terminal is in control function, the message CTRL appears on the right
side of the status ling, preceeding the page number.
Forms Mode (CTRL) W When forms mode is activated, the FORMS indicator located on the keyboard
is lit. The forms mode can only be activated when valid delimiters are present
in the display data. Refer to subparagraph titled Forms Mode for more
detailed information concerning the operation of forms mode. To deactivate
form: mode, press (CTRL) Q.
Local State (LOCAL) If no other state is activated, the terminal defaults to the local state. When local
state is activated, LOCAL indicator on keyboard is lit.
Search Function (CTRL) A When search function is activated, it is possible to designate the “search”
character. To designate the search character, press (CTRL) E x (where
X equals the search character). To deactivate search function, press (CTRL)
S. Refer to subparagraph titled search function for more detailed information.
The default “search” character is ( $).
Receive State (RCV) When receive state is activated, RCV indicator located on keyboard is
lit. Activation of any other state deactivates receive mode.
Transmit State (XMT) When transmit state is activated, the XMT indicator on keyboard is lit.
Successful transmission of data or activation of the local state deactivates
transmit state.
HIGHLIGHT FUNCTIONS:
Negative Video (CTRL) U Screen shows dark characters on a green background.
Normal (Positive) Video (CTRL) I Screen shows green characters on a dark background.
MT 983/MT 993 Terminal Systems
1-16
Section |
Table 1-2. Keyboard Controls (Cont.)
Keyboard
Function Controls Action
Reverse Video (CTRL) H С.) Beginning at the cursor, the line is displayed in reverse video
(opposite of the rest of the screen).
Bright Video (CTRL) H (:) Beginning at the cursor, the remainder of the line is displayed in brighter
video than the rest of screen.
Blink (CTRL) H8 Beginning at the cursor, the remainder of the line blinks.
Underline (CTRL) H (7) Beginning at the cursor, the remainder of the line is underlined.
Secure (CTRL) H 9 Beginning at the cursor, the remainder of the line is filled in with solid
video.
EDIT FUNCTIONS:
Move Cursor Right -(—) Cursor is moved one character position to the right.
Move Cursor Left (-«—) Cursor is moved one character position to the left.
Move Cursor Down (4) Cursor is moved down one line.
Move Cursor Up (4) Cursor is moved up one line.
Move Cursor Home (HOME) Cursor is moved to the home position.
Carriage Return (RETURN) Cursor is returned to beginning of next (or same) line, depending on
configuration.
Character Insert (Line) (CHAR INS) Entered character(s) is inserted at cursor location and succeeding
characters on the line are moved one position to the right.
Character Insert (Page) (CTRL) (CHAR INS) Entered character(s) is inserted at cursor location and succeeding characters
on the page are moved one position to the right and down line by line
through the page.
Character Delete (Line) (CHAR DEL) Character at cursor location is deleted and succeeding characters on the
line are moved one position to the left.
Character Delete (Page) (CTRL) (CHAR DEL) Character at cursor location is deleted and succeeding characters on the
page are moved one position to the left and up, line by line.
Line Insert (LINE INS) Cursor line and succeeding page lines are moved down to allow for new
line.
Line Delete (LINE DEL) Cursor line is deleted and succeeding lines are moved up.
Line Movement Up (CTRL) V Cursor line is interchanged with line above.
Line Movement Down (CTRL) B Cursor line is interchanged with line below.
MT 983/MT 993 Terminal Systems
Section |
Table 1-2. Keyboard Controls (Cont.)
Keyboard
Function Controls Action
Roll Page Up (CTRL) N Page is rolled up one line while cursor remains stationary.
Roll Page Down (CTRL) M Page is rolled down one line while cursor remains stationary.
Scroll Data Up (CTRL) C 4) Display memory contents are scrolled up one line through the screen window
while cursor remains stationary.
Scroll Data Down (CTRL) ( Y:) Display memory contents are scrolled down one line through the screen
window while cursor remains stationary.
Page Advance (CTRL) (> ) Next page is displayed.
Page Back (CTRL) (<=) Previous page is displayed.
Clear Page (CLEAR) Cursor page is cleared (non-forms mode).
Clear to End of Line (CLR EOL) All data from cursor position to end of line is cleared (non-forms mode).
Clear to End of Page (CLR EOP) All data from cursor position to end-of-page is cleared (non-forms mode).
Enable Lower Case (CTRL) T Enables display of upper and lower case characters.
Disable Lower Case (CTRL) Y All characters are displayed in upper case.
Set Variable Tab (CTRL) P If terminal is configured for variable tab stops, establishes a tab stop at
current cursor position. If tab stop is already established, tab stop is disabled.
Clear Variable Tab Stops (CTRL) O Clears all variable tab stops, if set.
Tab Forward (TAB) Cursor moves forward to next tab stop.
Reverse Tab (RTAB) Cursor moves back to the previous tab stop.
Search Character (SKIP) Cursor moves forward to next occurrance of “search” character on the page.
COMMUNICATIONS FUNCTIONS:
Set Mobile Home (CTRL) (HOME) Establishes a start-of-transmission-point (other than screen home) at
the current location of the cursor.
Move Cursor to Data Comm (CTRL) (> ) Cursor moves directly to current location of data comm pointer.
Pointer
Set Data Comm Bit Rate;
600 baud (CTRL) space H (CTRL) Data comm bit rate is set to 600 baud.
1200 baud (CTRL) space J (CTRL) Data comm bit rate is set to 1200 baud.
1800 baud (CTRL) space K (CTRL) Data comm bit rate is set to 1800 baud.
MT 983/MT 993 Terminal
Section |
Systems
Function
Send Special Data Comm
Message
Table 1-2. Keyboard Controls (Cont.)
Keyboard
Controls Action
(CTRL) H (applicable key) Data comm character associated with applicable key (refer to figure D-3 in
Appendix D) is entered into display memory for the purpose of transmitting
a special message to the host system. The related symbol is displayed on the
screen. Note, this feature should be used causiously because of effect these
data comm control characters may have on host system.
PRINTER OUTPUT FUNCTIONS:
Print Screen Data from
Home to Cursor (Form Feed)
Print Screen Data from
Home to Cursor (No Form
Feed)
Print Unprotected Data from
Home to Cursor
1-18
(CTRL) С) Screen data from home position to current cursor location is printed on
optional printer with form feed taking place.
(CTRL) ()) Screen data from home position to current cursor location is printed on
optional printer without form feed taking place.
(CTRL) (©) All unprotected screen data from home to current cursor location is printed
on optional printer.
MT 983/MT 993 Terminal Systems
Section 2
SECTION 2
SYSTEM CONCEPTS
GENERAL
This section describes the memory allocation and the operational concepts of the MT 983/MT 993 terminal sys-
tem. These concepts include the major processes of the terminal, functional modes, and maintenance functions.
MEMORY ALLOCATION
Memory allocation is shown in a simplified form in table 2-1. Memory is laid out in terms of accessibility by
firmware, the host system, and the user.
Firmware Memory
Firmware memory is an area of memory which contains a set of operating microinstructions. These instruc-
tions control edit functions, confidence tests, interrupt procedures, and peripheral control. Firmware memory
is internal to the terminal and is protected from being altered either by Burroughs field engineers or by the
user.
Host System Accessible Memory
This area of memory is of primary concern to the host system programmer. It is subdivided into the data
comm buffer, display memory, status line buffer, and scratchpad memory.
The data comm buffer transfers data to and from the host system. Buffer size is configurable and can be up
to 2,000 characters with the expanded memory options.
The display memory contents may be viewed on the screen by accessing a selected portion of display memory.
The selected viewable area of display memory is called the screen window. Data goes from the display mem-
ory to the host system and is received in display memory from the host system via the data comm buffer.
Data can be entered into display memory from the keyboard. The display memory size is 1,920 characters
in the basic system and 3,840 characters with expanded memory.
The status line buffer is an area of memory which is used to assemble the 80-character status line (displayed
as the 25th line on the screen). Data is entered into this area of memory from the host system (special mes-
sages) and from the firmware memory (error messages).
The scratchpad memory is an area of memory reserved for configuration data. Most of this message area is
accessible to the user. Address location 0080 (Hex) through 00A0 (Hex) are the user-accessible areas of
scratchpad memory. The remaining locations of this memory area are only accessible by a Burroughs field
engineer. These locations contain such data as the terminal password and error message formats.
Table 2-1. MT 983/MT 993 Memory Allocation
Memory Area Accessible By
Data Comm Buffer
Display Memory
Status Line Buffer
Scratchpad Memory
System Firmware
Host System
User and Host System
Host System and Firmware
User and Host System
Firmware
2-1
MT 983/MT 993 Terminal Systems
Section 2
MAJOR PROCESSES
Figure 2-1 shows the major processes of the terminal and the main data paths they use to communicate with
one another. The major processes are:
Main process
Display store process
Video process
Keyboard interface process
Data comm interface process
Main Process
The main process includes four subprocesses: the keystroke interpreter, message synthesizer. message inter-
preter, and a driver to control the other three.
Input to the main process is keystroke signals, data comm control data, or host system messages.
A keystroke signal is simply an integer; its presence signifies either an actual keystroke or one generated by
the repeat function during continuous pressing of a key. The value of the integer identifies not only the key
responsible for the signal, but also whether the SHIFT key (which produces no keystroke signal itself) 1s simul-
taneously pressed.
Data comm control data advises the main process of an event that has occurred in the data comm interface
operation. There are 12 different events: some originate in the data comm network (false select. SOH re-
ceived); some in the data comm transceiver (transmit complete, receive complete).
The main process is characterized by the three operating states (local, receive, and transmit) as shown in figure
2-2. This diagram reflects how the main process functions with respect to the overall terminal operation.
Local State Operation
In the local state. the terminal neither transmits nor receives. Instead, the terminal is in an idle condition wait-
ing for keyboard input. A keyboard input starts the keystroke interpreting subprocess and the terminal remains
in the local state. During local state operation, the terminal is sensitive to data comm input request indications.
If such an indication occurs. the terminal sounds the audible alarm to alert the operator to put the terminal
into the receive state.
Receive State Operation
When an operator activates the receive key (RCV) or upon successful transmission of data. the terminal enters
the receive state. At this time the data comm input is received through the data comm interface process. If
the incoming data is control data. it is routed to the driver subprocess where it is acted upon. If the incoming
data is a message, the message is leaded into the data comm buffer; after which, message interpreting takes
place. If no other state is selected. the terminal remains in the receive state.
Transmit State Operation
When the transmit key (XMT) is activated. the terminal enters the transmit state. The driver initiates any con-
trol data to be transmitted. The message data to be transmitted is retrieved from memory through the display
store process and the message is composed by the message synthesizer subprocess. The message is then
loaded into the data comm buffer. When the message is fully loaded into the buffer. the terminal waits for
an invitation to transmit from the host system. Upon receipt of this signal. the message is transferred from
the data comm buffer to the data comm interface lines by the data comm interface process.
2-2
MT 983/MT 993 Terminal Systems
Section 2
VIDEO VIDEO CRT
PROCESS DISPLAY
DISPLAY
DATA
DATA STORE PROCESS |
WRITE READ WRITE READ READ
MAIN
PROCESS
Ÿ Ÿ
KEYSTROKE MESSAGE MESSAGE
INTERPRETER INTERPRETER SYNTHESIZER
Z 1 5 y 5
| | INPUT | OUTPUT
— — DATA DATA
| CONTROL +
CONTROL
DATA DATA COMM BUFFER
"9
à
KEYBOARD
CONTROL KEYSTROKE CONTROL INCOMING OUTGOING
DATA DATA DATA MESSAGES MESSAGES
INTERFACE DATA COMMINTERFACE
PROCESS PROCESS (TRANSCEIVER)
KEYBOARD DATA
DATA COMM
EP1765
Figure 2-1. Major Processes of Terminal
Keystroke Interpreter
The keystroke interpreter decodes and initiates operations invoked by a stream of keystrokes from the key-
board. The operations fall into two categories: control and non-control. Non-control operations are straightfor-
ward interpretations of the keyboard keys. Control operations extend the number of functions which can be
invoked from the keyboard. Control operations are initiated by the CTRL key and modify the interpretation
of the keyboard keys. A control operation is activated by pressing the CTRL key (shifted or unshifted), fol-
2-3
MT 983/MT 993 Terminal Systems
Section 2
TERMINAL
POWER ON
— — TEST IS
TRANSMIT
STATE
<
ONG
NC
O 7,
< <A,
4050
Mz Op
COMMANDS COMMANDS so
OR
MESSAGE
?
MESSAGE
©
TA
COMPOSE Фа
MESSAGE US
©
LOAD DATA KEYSTROKE
COMM BUFFER INTERPRETING
WAITING TO TRANSMIT
NO INVITATION
TO TRANSMIT
FROM HOST
?
TRANSMIT DATA
YES |— — —
CONFIDENCE
PERFORMED
ct
y
DRIVER
RECEIVE
STATE
CONTROL DATA
?
MESSAGE
DATA
RECEIVING
LOAD DATA
COMM BUFFER
MESSAGE
INTERPRETING
LOCAL DA
STATE SELECTED,
TRANSMIT
RECEIVE
EP1766
Figure 2-2. Main Processor Operation, Flow Diagram
lowed by one or more keyboard keys. The control operation remains in effect until one or more of the fol-
lowing events occurs:
|. The CTRL key is pressed a second time.
2. A key 1s pressed that ends a valid control sequence. (If the sequence began with shifted CTRL, the
CTRL operation allows for multiple key entries.)
3. A key is pressed that cannot be interpreted as part of a valid CTRL sequence (this has no effect
other than to erase the CTRL indicator).
The various CTRL-initiated control sequences are tabulated in Appendix B.
24
MT 983/MT 993 Terminal Systems
Section 2
Message Interpreter
The message interpreter performs a function for data comm operations similar to that performed by the key-
board interpreter for keyboard operations. The message interpreter decodes and initiates the operations in-
voked by the host system. The message interpreter extends the number of control functions available in the
standard 128-character ASCII set. The specific data comm character that allows for the extended control func-
tions is the ‘‘escape’” (ESC) character. The various ESC-initiated functions are tabulated in Appendix C.
Data Comm Buffer
The data comm buffer (DCB) is an area of memory which is used to temporarily store input messages so that
the individual parts of the input message can be interpreted without interfering with the data comm process.
For outgoing messages, the data comm buffer stores the fully composed message before it is transmitted.
Buffer Overflow
If an incoming or outgoing message is larger than the data comm buffer capacity, an audible alarm (buzzer)
sounds and a DATA COMM ERROR message is displayed on the status line. The length of the data comm
buffer can be specified during configuration of the terminal. The actual message is transferred; however, the
portion exceeding the boundaries of the data comm buffer will be missing.
Data Comm-Buffer Synchronization
The multipoint data comm network environment poses a buffer synchronization problem for the terminal. The
particular circumstance in which the problem arises is the arrival of a False Select, Group Select, or Broadcast
Select message at a time when the main process is either interpreting a previous message or loading the buffer
with an outgoing message. If the transceiver were to store the incoming message in the buffer, the operation
of one or the other process would be disrupted.
To prevent this, access to the buffer is regulated so that only one of the controlling modules can access it
at a time. For example, before starting to load the buffer with an outgoing message, the main process issues
a SEIZE DCB command and waits for a DCB SEIZED response from the transceiver before proceeding. It
retains control of the buffer until it issues a transmit (releasing not only the message for transmission but also
the buffer) or a RELEASE DCB (which occurs when the operator presses the local key to cancel a transmis-
sion).
The other instance in which the main process gains control of the buffer occurs when the transceiver acknowl-
edges an incoming message and sends a RCV DONE report to the, main process. The buffer then belongs to
the main process until it issues a RELEASE DCB command at the completion of message interpretation.
If a Fast Select, Group Select, or Broadcast Select message arrives while the main process has control of
the buffer. the message text is discarded and the transceiver responds with a NAK, signifying to the host ma-
chine that the message has not been properly received. When the transceiver has control of the buffer. a Fast
Select, Group Select, or Broadcast Select message is accepted and loaded into the buffer, although the main
process can still pre-empt the buffer with a SEIZE DCB command at any time before the incoming message
has been acknowledged.
Message Synthesizer
The message synthesizer has exclusive responsibility for assembling outgoing messages in the data comm buf-
fer. Outgoing messages are derived from various sources within the terminal. It is the function of the message
synthesizer to develop the outgoing message from one of the following sources:
I. Display data solely derived from display memory (keyboard or host system initiated).
2. A numeric message derived from entered keystrokes.
3. A specify message initiated by the SPCFY key. This message informs the host system of the present
position of the cursor.
4. System register data (host system initiated).
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5. A message indicating the terminal firmware level (host system initiated).
6. Reconfiguration response and successful restart response messages (host system initiated).
7. A message indicating the contents of the error log.
Keyboard Initiated Display Memory Messages
The XMT key initiates one of several buff-loading processes. depending on whether the cursor page is in forms
mode or non-forms mode and whether the page has an ETX (end-of-text) character.
Non-Forms
Forms
2-6
If the cursor page contains an ETX character, the message scan begins at the cursor and proceeds to
the ETX; if the scan encounters no ETX (every ETX on the page precedes the cursor). the scan stops
at the end of the page. When the cursor is positioned directly on an ETX. that character constitutes
the entire message. The transmit-home position is ignored.
If the cursor page contains no ETX, the scan begins at the transmit-home location. If the cursor is at.
or ahead of this location. the scan proceeds to the end of the page. If the cursor is beyond the transmit-
home location, the message scan ends at (but excludes) the cursor.
Loading the buffer from a non-forms page is interrupted if the scan encounters either a carriage return
(graphic V ) or an HT character (graphic >). When a carriage return is encountered. it 1s loaded. How-
ever. further loading is suspended until the scan reaches column 1 of the next line. When an HT charac-
ter is encountered, it is loaded; however. further loading is suspended until the scan reaches the next
tab stop column. In both cases. scanning continues unaffected by the suspension of message loading.
and all stopping conditions apply without alteration. Hence, a carriage return preceding an ETX or on
the last line of a page effectively terminates a message. An HT terminates a message when no tab stops
are set.
The buffer-loading operation of a forms page depends primarily on whether the search function is acti-
vated. The combination of search and forms is a special case. Scanning starts at the transmit-home loca-
tion and stops at an ETX or the end of the page. The carriage return and HT characters have the same
effect as in a non-forms page. and the forms delimiters have no special significance.
The non-search loading operation is an entirely different process. It recognizes forms mode by skipping
over protected fields as it loads. This operation interprets the FS graphic ( ff ) as an opening delimiter.
in addition to the GS and US characters. Loading stops when the scan encounters any delimiter and
resumes one character past an opening delimiter. The delimiters themselves are not loaded. For buffer
loading purposes, a forms mode page consists not of protected and unprotected fields. but of transmitta-
ble and non-transmittable fields. When the scan encounters a transmittable HT character. the character
is loaded and loading is suspended until the next opening delimiter. A transmittable carriage return char-
acter is loaded; however. loading does not resume until an opening delimiter is encountered on a subse-
quent line.
The points in forms mode at which the message scan begins and ends depend primarily on the configura-
tion of the terminal. One option enables the message scan to start at the transmit-home location and
continue until it encounters either an ETX or end-of-page. At the starting point. loading Is either active
or suspended. depending on whether the transmit-home location is in a transmittable field. Cursor posi-
поп 1$ immaterial. except that it may affect the transmit-home position.
In the other option, the end points of the message scan depend on the presence or absence of an ETX
in the page being scanned. If the page has an ETX. the scan begins at the cursor and continues to an
ETX or end-of-page. If the cursor is in a GS field. the starting point of the scan 1s adjusted left to the
beginning of the field. A user wishing to send a message beginning with a GS field need not move the
cursor manually to the left end of the field. If the page contains no ETX. the scan begins at the transmit-
home location and stops at the cursor. The cursor character itself is not loaded unless the cursor is
MT 983/MT 993 Terminal Systems
Section 2
in a GS field. If the scan never encounters the cursor, or if no characters have been loaded when the
scan encounters it, the scan continues to the end of the page.
System-Initiated Display Memory Message
The host system can initiate a terminal output message consisting of display memory data. This output message
is initiated by receipt of an escape (ESC) control character followed by a open parenthesis (О character from
the host system. The effect of this operation is delayed until the incoming control message is interpreted.
The message scan of a page always begins at column 1 of line 1. If the data comm pointer is at the scan's
starting position, the scan proceeds to the end of the page. Otherwise, it stops when it reaches the data comm
pointer position. In either case, the scan stops at once if it encounters an ETX. During this message scan,
the criteria for loading are the same as in the keyboard-initiated display memory message.
Keyboard-Initiated Numeric message
This message is invoked by keyboard control sequence CTRL nn XMT where n can be any number from 0
to 9. This operation loads the characters ESC, m, n, ETX into the buffer for transmission to the host system.
(The designations m and n stand for any two numeric digits entered from the keyboard.)
Specify Message
The SPCFY key loads the ESC character followed by the row (line) and column numbers of the cursor loca-
tion, augmented by a value of 31, and followed by ETX.
Scratchpad Memory Data Message
This message type enables the host machine to read the configuration data contained in the terminal scratchpad
memory. Unlike the host system-initiated display memory message, where the effect is delayed until after in-
terpretation of the incoming control message is complete, this control message is acted upon as soon as the
message interpreter recognizes it. The remainder of the control message 1s never interpreted. (Refer to the
subparagraph headed Configuration Mode in this section and to Appendix A for detailed information concern-
ing terminal configuration.)
Firmware Level Message
An incoming control character sequence of ESC space V terminates interpretation of the message being re-
ceived and loads the buffer with the terminal firmware version and patch numbers.
Reconfiguration Response and Successful Restart Response Messages
These messages are a result of a reconfiguration of the terminal or a successful terminal restart operation.
The terminal goes off-line prior to reconfiguration or restarting. Provided that no errors are found, the terminal
returns on-line and loads the data comm buffer with the same message (six asterisks) appearing on the screen.
Reconfiguration operations activated from the keyboard do not invoke any such transmission.
Error Log Message
This operation loads the data comm buffer with a string of 10 hexadecimal characters representing the current
state of the error log. The second character indicates the number of data comm errors. The sixth character
indicates the number of printer errors. All other characters are 0. (Refer to the paragraph titled Mainte-
nance Functions in this section for more information concerning the error log.)
Data Comm Interface Process (Transceiver)
The terminal is equipped with a multipoint data comm transceiver which is used for communication on a
shared data comm line (a line connecting a host system with several terminals).
MT 983/MT 993 Terminal Systems
Section 2
The data comm transceiver operates in accordance with the Burroughs multipoint procedures as described 1n
Section 3.
The multipoint transceiver operation consists of various states. The process 1s driven from state to state by
two types of events: commands from the main process and the transmission of certain character sequences
by the host system.
Transceiver/Main Process Interface
The interface between the data comm transceiver and the main process consists of:
1. The data comm buffer, through which the two modules communicate incoming and outgoing mes-
sages.
2. A set of commands issued by the main process.
3. A set of reports issued by the transceiver.
The commands and reports serve not only to inform each process of events that have occurred in the other,
but also to coordinate the use of the data comm buffer.
Transceiver Commands
The commands issued by the main process to control transceiver operation are:
Command Definition
TRANSMIT Signals transceiver that buffer has a message ready for transmission; this command also releases the
buffer to the transceiver.
RECEIVE Puts transceiver in a state in which normal select requests from the host system are acknowledged.
OFF-LINE Puts terminal off-line (for reconfiguration).
ON-LINE Puts terminal on-line.
DISCONNECT Commands transceiver to issue DLE-EOT sequence.
SEIZE DCB If buffer is not already in use by transceiver, this reserves it for the main process.
RELEASE DCB
CLEAR
ABORT
Reports
Main process relinquishes control over buffer to transceiver.
Returns transceiver to its IDLE state from all other conditions except DCB SEIZED; transceiver
replies with IDLE report.
Similar to CLEAR, except that transceiver gives no reply if its condition is DCB SEIZED. Allows
reception of an incoming message to be aborted unless the message has already been acknowledged.
The reports are signals by which the transceiver acknowledges commands received from the main process and
advises it of significant data comm network events. The reports and their definitions are:
Report Definition
IDLE Response to CLEAR command.
DCB SEIZED Response to SEIZE DCB command.
RCV READY Response to receive command.
XMIT DONE Reports successful transmission of outgoing message.
GBSEL Reports incoming GROUP SELECT or BROADCAST SELECT message.
RECEIVING Reports reception of incoming message header.
RCV ERR Reports end of incoming message containing a parity error, or message termination by EOT.
RCV DONE Reports end of valid incoming message; control of buffer passes to main process.
DCB OVERFLOW Reports incoming message too long for buffer.
XMIT READY Response to transmit command.
FSEL Reports incoming FAST SELECT message.
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Section 2
Keyboard Interface Process
The keyboard interface process controls all keyboard operations. The majority of keyboard keys are ordinary
text keys (letters, digits, punctuation marks); however, it is convenient to view every keystroke as a command
which 1s forwarded to the keystroke interpreter. In addition, control data to light various keyboard indicators
and to enable various keyboard functions is transferred to the keyboard by the interface. This process is ac-
complished through serial input/output (SIO) procedures. Refer to Section 4 for a description of SIO interface
procedures.
Display Store Process
The display store process stores in display memory characters received from the keyboard or data comm and
IS the source of characters displayed on the screen and transmitted to data comm.
Display memory is organized into lines which are all the same length (either 40 or 80 characters depending
on configuration). The lines are grouped into pages, all of equal size (also dependent upon configuration). A
common configuration of the terminal divides its display store into two pages, both consisting of 24 lines of
80 characters, for a total of 3,840 characters.
That portion of display memory data which is displayed is referred to as the screen window. Figure 2-3 illus-
trates a typical relationship of pages and screen window to the total display memory.
As stated, the display store process has two sources of data: the keyboard and the data comm port. Each
of these sources has a separate pointer which denotes (at any time) the location where incoming data is stored
in display memory. One of these pointers (the keyboard cursor) is usually displayed; that is, the displayed
portion of the display memory always includes the cursor location. The actual position of the cursor is indi-
cated by a reverse-video field, which may be made to blink or to be turned off (configuration dependent).
The other pointer is an invisible data comm pointer. Its position can only be inferred from the effects of data
comm Inputs, or by means of specific operations that align the two pointers (move one of the pointers to the
current location of the other). With the exception of these few specific operations, the positions of the two
pointers are entirely independent. They may be in different lines or even different pages, controlling completely
independent input processes.
DATA LINES
PAGE 1
- [ a
> PAGE 2
A
> --— STATUS LINE
7
[ I
> PAGE 3 \— J
DISPLAY SCREEN WINDOW
DISPLAY MEMORY
EP1767
Figure 2-3. Typical Display Memory Organization
MT 983/MT 993 Terminal Systems
Section 2
Video Process
The video process converts data retrieved from display memory into video presentations on the screen. The
individual data characters retrieved from memory are decoded by a character generator which is used to gener-
ate the various alphanumeric characters and symbols of the display. The characters and symbols displayed
are dependent on the character set being used with the terminal. Refer to Appendix D for a presentation of
the character sets.
FUNCTIONAL MODES
The terminal can be operated in one of three modes: forms, non-forms, and configuration mode.
Forms Mode
Forms mode protects part of a page from being modified, particularly by the keyboard operator. When a forms
page is displayed on the screen, the keyboard operator is permitted to alter the unprotected areas (fields) but
1s prevented from altering the protected areas (fields).
The designation of forms mode entails determining whether a page is a valid forms page.
A valid forms page contains at least one US or one GS delimiter. However, it is possible for a
page to contain other delimiter symbols, particularly when entered from keyboard. This is because the key-
board does not include US or RS keys, although it does have a GS key: as a result, the terminal allows other
characters to represent the US and RS delimiters. The actual identities of alternate delimiters are configuration
options. Common alternate delimiters are the parenthesis, brace, or bracket. The terminal scans the entire page
and converts every alternate delimiter into the US graphics symbol or the RS graphic symbol (depending on
the alternate delimiter encountered).
Keyboard/Data Comm Differences
In some aspects, the operation of the terminal in forms mode depends on the source of input (keyboard or
data comm interface). For example, the forms indicator light indicates whether the page in which the cursor
is located is in forms mode. It flashes on and off when the cursor page switches between forms mode and
non-forms mode, and also as the cursor is moved from a forms page to a non-forms page. No such indication
is provided for the data comm pointer (nor is the host system able to determine if the data comm pointer
1$ in a forms page).
During editing operations, the protected fields of a forms page are protected only from keyboard inputs; data
comm messages can freely over-write protected fields, although the delimiters are fully protected.
Another difference is in the number of different types of fields that can be recognized. Keyboard operations
recognize three types of fields: protected (RS), left-justified unprotected (US), and right-justified unprotected
(GS); whereas data comm operations recognize only protected and unprotected (there is no distinction made
between left and right-justified unprotected fields).
In operations invoked from the keyboard, US fields are normally filled from left to right (just like ordinary
text entry), the cursor can be freely moved back and forth, and text can be entered at any position. A GS
field is quite different. It has but a single data-entry point, the right-most position of the field. Positioning the
cursor anywhere else in a GS field disables editing operations just as if it were in a protected field. Text entry
in a GS field is also different. Instead of writing a character and then moving the cursor to the right, it first
shifts the characters in the field left (discarding its left-most character) and then writes the character; the cur-
sor, therefore, never moves at all.
Data comm operations treat GS and US fields identically. These fields are handled in some ways like RS fields.
Straight text entry is allowed in all three fields, storing each text character and advancing the data comm point-
er. The distinction occurs at the end of a field. When the data comm pointer advances to a position occupied
by a delimiter, it immediately jumps to the beginning of the next unprotected field (making no distinction be-
tween GS and US fields). Most operations other than text entry (character insertion and deletion, for example)
are allowed only in GS/US fields.
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Section 2
Entry Into Forms Mode
Pages can be switched to forms mode from the keyboard by the sequence CTRL W or by a data comm mes-
sage with the sequence ESC W. In addition, the terminal can be configured so that a DC? character in a data
comm message has the same effect as ESC W, provided that the data comm pointer page is not already in
the forms mode. If the pointer page is already in forms mode, CTRL W and ESC W have no effect, but DC2
(depending on terminal configuration) switches the page to non-forms mode.
The first step in a switch-to-forms-mode operation is a scan of the page containing the pointer. During this
scan, it is also noted whether the page satisfies the requirement for forms mode (that it contains at least one
opening delimiter followed by a non-delimiter). If the page fails this test, the operation terminates, leaving the
pointer in the home position of the page.
The second step (undertaken only if the page meets the forms criterion) is to record that the pointer page
is now in forms mode and, if it is a keyboard operation, to turn on the FORMS indicator light.
The third and last step, which is to position the pointer in the page, depends on whether the search feature
is activated. If the search feature is off, the pointer jumps to the first unprotected location of the page. If
the operation is invoked from the keyboard, then an HT character may be stored in the leftmost position of
the field, depending on terminal configuration. If the search feature is activated, the page is scanned for an
instance of the search character. If one is found preceding the first delimiter, the pointer is left at that location
and a skip flag is turned on; otherwise, the skip flag is turned off and the pointer is placed as if the search
feature were off.
Exit from Forms Mode
From the keyboard, entering CTRL Q sets the page to non-forms mode and leaves the cursor at the home
position of the page. If the terminal is so configured, the entire page is cleared as well.
In a data comm message, the sequence ESC X sets the data comm pointer page to non-forms mode and puts
the pointer at the page’s home position. If the data comm pointer is on the cursor page, the FORMS light
is cleared as well. The terminal can be configured so that a DC2 character has the same effect as ESC X.
In addition, the reception of a data comm message (regardless of its content) can affect the forms mode state
of a page in two distinct situations. In one case, the terminal can be configured so that the reception of the
SOH character in the heading of a message addressed to the terminal clears the entire page. leaving it in non-
forms mode and the data comm pointer in the home position. The other situation occurs as interpretation of
a data comm message begins. Regardless of the message content, the data comm pointer page is put into non-
forms mode. turning the FORMS light off if the cursor is located in the same page. This is the only forms-
exit operation that does not affect the location of the pointer involved.
Configuration Mode
Although the functions and features of the terminal are basically fixed. many parameters of its operation are
changeable. These are variables with values that can be altered (either from the keyboard or data comm inter-
face) for the duration of terminal operation (until power-off) or can be preserved through power-off periods.
These variable parameters (such as page size, data comm transmission rate. cursor blink) are collectively re-
ferred to as terminal configuration options. The following subparagraphs describe the aspects of terminal con-
figuration. Refer to Appendix A for detailed information concerning identification and alteration of the terminal
configuration.
Scratchpad Memory
The terminal memory contains an area of scratchpad memory which is used to temporarily store the terminal
configuration data. Terminal behavior is directly controlled by the data stored in this area of memory. At turn-
on or restart. the scratchpad memory is automatically loaded with a fixed set of terminal configuration
parameters derived from a separate device: the EAROM (electrically alterable read-only memory). This fixed
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Section 2
configuration data is preserved in the EAROM through power-off periods. However, it is changeable by the
user (through the keyboard) or the host system (through data comm controls). When the terminal is turned
off, the contents of the scratchpad memory are destroyed, thereby requiring a reload from EAROM when the
terminal is powered-on.
The scratchpad memory consists of a string of eight-bit bytes. Each byte is identified by a four-digit
hexadecimal address. The contents of the scratchpad memory can be displayed for the user on the display
screen and can be modified from the keyboard. The host system can also read the scratchpad memory and
write into it. Changes to the displayed scratchpad data on the screen do not in themselves alter the configura-
tion data. It takes a configuration operation by the user or the host system to transfer the displayed scratchpad
data into the scratchpad area of memory.
À transfer of displayed scratchpad data to the scratchpad memory may not always be allowed. When a transfer
operation is attempted. a comparison is made between the displayed configuration data values and the specific
limitations of the terminal. If the displayed values violate or exceed the specific limitations of the terminal,
the configuration does not take place and a message to this effect is displayed on the top line of the screen.
(For example, the storage allocation for display data can not exceed the total available memory space in the
terminal.)
Default Terminal Configuration
The terminal contains default configuration parameters which are installed by the factory in a non-accessible
area of memory. If during terminal configuration operations by the user a problem occurs where the EAROM
contents are destroyed. recovery can be made through the use of the default configuration data. The user can
transfer this default configuration data to the scratchpad memory by pressing a key on the keyboard (prefer-
ably the space bar) during the operation of the terminal confidence test at power-on or restart. At this point
the user can recover to the desired terminal configuration as follows:
I. Display scratchpad memory contents.
2. Make desired configuration changes to the displayed data.
3. Perform a terminal configuration operation to write the changed data into the scratchpad memory
from the screen.
4. Perform an EAROM rewrite operation to transfer the scratchpad memory contents to the EAROM
to re-establish the fixed configuration parameters. Refer to Appendix A for detailed information on how
to enter terminal configuration data into the scratchpad memory and EAROM.
Terminal Password
An operator is required to enter a four-character password to gain access to the scratchpad area of memory.
This requirement protects against an unauthorized user making changes to the terminal configuration. The pas-
sword can consist of any four characters. The default password set by the factory is MODE. The password
can be changed by a Burroughs field engineer to customize the password for a particular user.
MAINTENANCE FUNCTIONS
The terminal has certain built-in maintenance functions to aid the user in determining the operational state
of the terminal system. These include:
A built-in confidence test
Status line error messages
A displayable error log
Confidence Test
The terminal contains a built-in confidence test which is automatically run every time the terminal is powered-
on or restarted. This confidence test can also be initiated by the user from the keyboard by the entry of the
following keystroke sequence: CTRL space D CTRL. The confidence test can also be remotely initiated from
the host system by sending the data comm instruction ESC space D.
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Section 2
A successful performance of the confidence test is indicated by six asterisks ( * * * * * *) on the
first display line of the screen with the terminal in the local state (local indicator is lit; all other indicators
are off). If the confidence test is not completed successfully, the terminal can be left in various operational
conditions.
The following are the normal observable indications which occur during the operation of the confidence test:
1. Buzzer sounds once approximately 1 second after power-on or restart and then goes off.
2. After buzzer sounds, all keyboard indicators light and stay lit for approximately 10 seconds; after
which, they go out.
3. Flashes of video appear on the screen for several seconds.
4. local indicator relights; other keyboard indicators stay off.
5. Six asterisks are displayed in first line of display screen. Terminal is ready for operation.
Any indications other than those just described may indicate a malfunction in the terminal.
Status Line Error Messages
The following error messages are displayed on the status line to signify operational errors:
DATA COMM ERROR
PRINTER ERROR
RECEIVE ERROR
KEYSTROKE LOST
Error Log
The terminal maintains a record of the number of occurrences of certain errors. This record, known as the
error log, can be displayed on the screen by the following keystroke sequence in upper case (shifted) form:
CTRL RWxxxx CTRL RLxxxx, where xxxx is the four-character password required to gain access to the re-
stricted areas in terminal memory. Error log contents can also be transmitted to the host system in response
to an ESC R L instruction in a data comm message. Although the error log provides for five distinct types
of error reporting, only two types (data comm errors and printer errors) are used at this time. The other three
are reserved for future use.
The reported error counts are limited to 15, and are set to 0 only by the system confidence test. The data
comm error log counts only parity errors and block check errors in incoming messages. Buffer overflows.
which cause a data comm error message to appear on the status line. are not counted. The error log format
in shown in figure 2-4.
For example. the terminal might respond to a display error log request with the following hexadecimal digits:
0B0040000
indicating that 11 data com errors and 4 printer errors have occurred.
MT 983/MT 993 Terminal Systems
Section 2
IGNORE THESE
DIGITS
tory
RESERVED FOR FUTURE USE
т?
X
> <<—
o-«<«4—
> “<—
PRINTER ERRORS
RESERVED FOR FUTURE USE
RESERVED FOR FUTURE USE
EP1768
Figure 2-4. Error Log Format
MT 983/MT 993 Terminal Systems
Section 3
SECTION 3
DATA COMMUNICATIONS INTERFACE
GENERAL
Data communications between the terminal and host system consist of control character sequences and data
messages which are transferred between the host system and the terminal. These character sequences and mes-
sages are transferred over data communication interface circuits. This transfer of data can be carried out
through the use of various communications procedures (line disciplines). This section provides an overview
of data communications interface. Specific references are made to other documents for more detailed informa-
tion.
CONTROL CHARACTER SEQUENCES
The data comm control characters which are used by the terminal are defined in Appendix C.
ILLEGAL CHARACTERS
An illegal character is defined as a character having incorrect parity, or a control character appearing incor-
rectly in a predefined sequence. The terminal tests each character received for correct parity and accepts con-
trol characters only in the sequence defined for the communications procedure being employed.
DATA ERROR CHECKING
Upon receiving a message, the terminal employs two types of error checking. The first is a character parity
check utilizing the eighth bit of each received character as the parity bit.
The second error check is a longitudinal binary sum (without carry) of the seven data bits of the received
characters following SOH or STX, up to and including the ETX. The longitudinal sum is contained in the block
check character (BCC), which also contains the character parity bit. All received characters are included in
the BCC check. If the tests for character parity within the text of the message and longitudinal redundance
are correct, the terminal responds with an ACK character. If either error check fails, the terminal responds
with a NAK character.
TERMINAL ADDRESS
Each terminal has a unique address through which the host system or another terminal can access it. The
terminal address (ADI, AD2) is set through configuration change. The ADI] and AD2 address digits are set
in scratchpad memory locations 0089 and 008A. (Refer to Appendix A.)
The terminal group poll and group select addresses are separate from the terminal address and are also set
through configuration change. The group poll address (GPL1, GPL2) is set in scratchpad memory locations
008E and 008F. The group select address (GSL) is set in location 008B. (Refer to Appendix A.)
TRANSMISSION NUMBER
À transmission number feature is provided by the terminal to assign numbers to outgoing messages. The trans-
mission number is used to identify send messages and to determine the loss or duplication of these messages.
The transmission number is configurable and can be set in scratchpad memory location 0088. (Refer to Appen-
dix A.)
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Section 3
COMMUNICATION PROCEDURES
The terminal can utilize any of the following multipoint communications procedures for transmitting and receiv-
ing data:
Poll
Group Poll
Select
Fast Select
Broadcast Select
Group Select
Contention
The following subparagraphs provide a brief description of the communication procedures. The communications
procedures (line disciplines) utilized in the terminal are described in greater detail in the Burroughs Basic Data
Communications Line Control Procedures, form 1086956, and Burroughs Basic Data Communications Line
Control Procedures for TD Series Terminals, form 1097805.
Poll (POL)
The POL procedure is used to transmit data and status information to the host system. In this procedure,
the terminal is polled as an individual entity.
Group Poll (GPL)
The GPL procedure is an option of the standard poll procedure. In the GPL procedure, a group of terminals
are polled as a group through their group address.
Select (SEL)
The SEL procedure is used for receiving data from the host system. A selection will be acknowledged by
the selected terminal.
Fast Select (FSL)
The FSL procedure is used when it is desired to transmit a message to a terminal whose status is known
to be “receive ready” or when the host system does rot choose to test the receive status of the terminal.
Broadcast Select (BSL)
The BSL procedure is used when the host system desires to transmit a message to all terminals on a line.
The BSL overrides the terminal's transmit and receive states causing the terminal to automatically switch to
the receive state and sound it's alarm.
Conteniion (CON)
The CON procedure enables the host system to terminate polling of the multipoint network after placing the
system in contention. Any terminal desiring to transmit a message to the host system may do so by initiating
a host system polling action through the transmission of a special character sequence to the host system.
COMMUNICATIONS INTERFACE
The terminal is capable of operation in a two to four-wire circuit with half-duplex asynchronous data communi-
cations interface. (conforming to EIA Standard RS232C, CCITT Recommendation V24 for the international
market) the two-wire direct interface, and the Burroughs direct asynchronous access (BDAA) interface to the
extend described in this manual. Table 3-1 lists the characteristics of the various interfaces.
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MT 983/MT 993 Terminal Systems
Section 3
Table 3-1. Communications Interface Characteristics
Type of Interface
Asynchronous Data Set
(EIA RS232C or CCITT) -
Synchronous Data Set
(EIA RS232C or CCITT)
Two-Wire Direct Interface
(TDI) (Asynchronous)
Burroughs Direct Asynchronous
Access (BDAA)
Concatenation from a Single
Asynchronous Data Set
Concatenation from a Single
Synchronous Data Set
Characteristic
150 to 1800 bps*
1200 to 9600 bps
150 to 9600 bps at 1000 feet
150 to 38,400 bps and up to 15,000 feet
(But not concurrently).
Maximum of 1000 feet of concatenated
cable between terminals.
The maximum total concatenation cable
length from first to last terminal is based
on data rate, as follows: 9600 bps - 400
feet, 4800 bps - 800 feet, 2400 bps - 1600
feet, 2000 bps - 2000 feet, 1200 bps - 3200
feet, 600 bps - 6400 feet.
* Bits per second.
Two-Wire Direct Interface (TDI) Communications
The terminal 1s capable of two-wire direct interface (TDI) with the conditions:
I. Character format is 10 bits (asynchronous).
2. Data transmission rates for asynchronous data may be selected from the following rates:
150 bps
1200 bps
1800 bps
2400 bps
4800 bps
9600 bps
The characters of a message sequence should be in accordance with the terminal multipoint communications
procedures (listed under Communications Procedures) to the extend applicable to the terminal.
The cable used for the TDI connection should be twisted two-wire cable and have a maximum length of 1,000
feet. This cable is a single cable with multiple drops along its length. The TDI cable characteristics, including
gauge and shielding, conform to Burroughs part number 1110 0062 The number of terminals in a TDI installa-
tion is limited to a maximum of nine on a 1,000-foot cable. Refer to Burroughs Terminal Systems Cabling Ref-
erence Manual, form 1105012.
Burroughs Direct Asynchronous Access (BDAA) Interface
The terminal is capable of meeting the requirements of the BDAA interface.
MT 983/MT 993 Terminal Systems
Section 3
Data rates, up to a maximum of 64K bps, at a maximum cable distance of 15,000 feet are provided. The actual
data is dependent on the type of transmission line cable used and the length of the cable separating the most
distant locations. The combination of parameters of data rate, maximum installed cable length, and cable wire
size provide the limits which govern each BDAA installation containing a single multipoint The number of ter-
minals in a BDAA installation containing a single multipoint line is limited to a maximum of 20.
With BDAA, the connection from each customer-installed BDAA cable and junction box to each terminal in
the multipoint network is made with the BDAA Device Connection Kit. Refer to Burroughs Terminal Systems
Cabling Reference Manual, form 1105012.
Concatenation Cables
A means is provided for connecting multiple terminals to a single data set. For concatenating the terminal.
two specific cable types are required for compliance with the various possible combinations:
[. Terminal to Data Set: A family of cable lengths (15, 25, 50 or 100 feet) which contain a plug on the data
set end of connectors 1, 2, or 3 (table 3-2) depending on the domestic or international market being
served, and a jack on the terminal end conforming to connector 1. For domestic applications this cable
type (using connector 1 on both ends) is identical to the cable of (2).
2. Terminal to Terminals: A family of cable lengths (15, 25, 50, or 100 feet) which contain a plug and jack
on the respective ends, conforming to the mating pair of connectors (table 3-2).
Asynchronous Data Communication
Asynchronous (RS232, TDI, or BDAA) data communication uses even parity. Each character is serially trans-
mitted using 10 bits per character. The meaning of each bit of the character is. in order: a space bit, seven
ASCII code bits with the least significant bit first, a parity bit, and a mark bit. When data is received or trans-
mitted, the baud rate and baud timing sequence are produced by a baud rate counter in the terminal.
Synchronous Data Communication
Synchronous data communication uses odd parity. Each character is serially transmitted using eight bits per
character. The meaning of each it of the character is, in order: seven ASCII code bits with the least significant
bit first and a parity bit. When data is received or transmitted. the baud rate timing is received over separate
timing lines from the communications interface. The SYN character is used to provide a signal on the line
to establish and maintain synchronism between the terminal and the central processor. When a synchronous
transmission is started, at least four SYN characters must be transmitted before any other character is trans-
mitted in order to enable synchronization.
3-4
MT 983/MT 993 Terminal Systems
Section 3
Table 3-2. Communications Interface Connector Assignments
RS232C
Circuit EIA CCITT Connector No. 1 Connector No. 2 Connector No. 3
Protective Ground AA 101 1 1 1
Signal Ground AB 102 7 7 7
Transmitted Data BA 103 2 2 2
Received Data BB 104 3 3 3
Request to Send CA 105 4 4 4
Clear to Send CB 106 5 5 5
Data Set Ready CC 107 6 6 6
Data Terminal Ready CD 108.2 20(4) 2004) 20(4)
Connect Data Set to Line 108.1 20(4) 20(4)
Ring Indicator (9) CE 125 22 22 22
RCV Line Signal Detector CF 109 8 8 8
Data Signal Rate Selector CH 111 23(5) 23(5) 11(5)
Select Transmit Frequency 126 11(6) 11(6)
Transmit Signal Timing DB 114(7) 15 15 15
Element
Receive Signal Timing DD 115(7) 17 17 17
Element
Select Standby 116 1 24 24
NOTES
1. Connector No. 1 consists of Burroughs parts 1694 7244, 1699 4345 (2), and 2471 2036, and
shall be similar to the Bell connector or equivalent.
2. Connector No. 2 consists of Burroughs parts 1694 7244, 1900 2484, or 1900 2534, and shall
be similar to the SEL connector or equivalent.
3. Connector No. 3 consists of Burroughs parts 1472 0635, 1473 9213, or 1257 0420 (2), and shall
be similar to the BPO connector.
4. “Data Terminal Ready” and “Connect Data Set to Line” shall be used as follows:
(a) Switched Lines - provide positive voltage to maintain connection for duration of call.
(b) Leased Lines - provide permanent positive voltage for leased -line operation.
5. The data signal rate selector lead shall provide a positive or negative voltage for data rate
selection. A positive voltage on this lead shall condition the data set for the higher data rate as
required for leased line operation. A negative voltage on this lead shall condition the data set for
the lower data rate as required for switched line operation. Positive or negative voltage selection
shall be made through field engineering adjustment. Data signal rate selection shall be used with
CCITT V23 and V26 data sets
6. The select transmit frequency lead shall provide a positive or negative voltage for frequency
selection. A positive voltage on this lead shall condition the data set for the operating frequency.
The select transmit frequency shall be used with the V21 data sets.
7. Circuits DB and DD are used only with synchronous communications systems and are not
applicable to the terminal.
8. Circuit CE (Ring Indicator) is not used by the terminal.
3-5
MT 983/MT 993 Terminal Systems
Section 4
SECTION 4
SERIAL VO INTERFACE
GENERAL
Communication with peripheral (channels) is accomplished via a serial I/O (SIO) interface which consists of
a two-signal synchronous serial bus. A device number, which is easily modified. is used to identify the periph-
eral in the serial bus interface.
INTERFACE CONTROLS
Interface communication is controlled by a three-bit instruction code. The I-code is sent by the terminal to
the peripheral (the peripheral is always a slave station to the terminal) over the three least-significant data
lines (DBO-DB2). immediately followed by data bits.
The instructions signified by the I-code are:
Interface Data Bits Instruction
I-Code INVITATION TO INTERRUPT
SELECT DEVICE
GFT DATA
SEND DATA
GET DEVICE STATUS (DSTATUS)
SEND DEVICE COMMAND
GFT INTERFACE STATUS (ISTATUS)
2
0
0
0
0
1
]
]
1 SEND INTERFACE COMMAND
— © — © — се — © ©
Invitation to Interrupt
The Invitation to Interrupt instruction is a request by the terminal that a peripheral device with a pending
interrupt send its device number. A device which needs servicing responds to the Invitation to Interrupt I-
code by transmitting its device number. The device monitors the data line as it transmits each bit in order
to detect a conflict with a higher priority unit. If a 1 is detected on the serial interface line when the device
attempting to transmit a 0, the device does not transmit the rest of its device number. If all eight bits of the
device number are successfully transmitted, the device is considered to be selected.
The terminal may immediately deselect the device by sending another Invitation to Interrupt or Device Select
I-code. If the terminal deselects the device prior to first performing a Get IStatus, then the device responds
to subsequent Invitation to Interrupt I-codes.
The device continues to attempt to interrupt the terminal until it is successful or until it is selected by a Device
Select I-code.
Device Select
During this interface control seguence, the terminal transmits both the I-code and a data character. If the data
Character matches the peripheral device number, the printer 1s selected. The device remains selected until the
next Device Select or Invitation to Interrupt I-code. Only when the device is selected will 1t respond to a
Get or Send I-code. |
GET Instructions
The GET instructions cause a selected peripheral device to transmit data to the terminal. The peripheral trans-
mits one byte o data (most significant bit first) to the terminal. Note that only one eight-bit byte of information
4-1
MT 983/MT 993 Terminal Systems
Section 4
is transferred with each command. There are three Get instructions which are recognized when the device
is selected: Get Interface Status (ISTATUS), Get Device STatus (DSTATUS), and Get Data.
Get IStatus
The device transmits an eight-bit word indicating the state of the device serial interface.
The device interrupts the terminal whenever the device is in a Receive-Ready state or when its device status
changes significantly. A significant device status change may be the device entering the Idle state, or operator
attention being required or a device failure.
Get DStatus (Device Status)
This instruction is used to access the device status bytes. Following a Get IStatus instruction which indicated
that device status had changed, the terminal is expected to issue a Get DStatus command. (Bits 3 and 2 of
the interface status word are equal to 01).
Get Data
The Get Data instruction causes a selected peripheral to transmit data to the host terminal. When this instruc-
tion is decoded by the device, it puts the data into the data field, high-order bit first.
Send Instructions
The Send instructions cause a selected peripheral to receive data from the terminal. The peripheral takes the
input data from the data field, the most significant bit first. There are three Send Instructions which are recog-
nized by the terminal: Send Data, Send Device Command, and Send Interface Command.
Send Data
The Send Data I-code is only recognized when the device is selected. This I-code will be followed by a byte
of data from the terminal. Prior to each Send Data I-code, the terminal must ensure that the device is Receive
“Ready by checking its interface status. Following each Send Data I-code, the printer interrupts the terminal
when it is again Receive Ready. In the interim, the device interface status is invalid.
The device interrupts the terminal only once should the device go Receive Ready while it is trying to interrupt
the terminal due to a change in its device status, or should the device status change while it is attempting
to interrupt the terminal because of having gone Receive Ready. The interface status indicates a change in
device status. After the terminal has read the device status, it should check the interface status to determine
if the device is Receive Ready.
Send Device Command
This I-code is sent to the terminal by the device as a request for a device command. The terminal responds
with a device command, if applicable.
4-2
MT 983/MT 993 Terminal Systems
Section 5
SECTION 5
KEYBOARD
GENERAL DESCRIPTION
The keyboards presently used with the MT 983/MT 993 terminal systems are the Burroughs model TP 110 al-
phanumeric keyboard and the TP 119 data preparation keyboard.
FUNCTIONAL CHARACTERISTICS
Keyboard Code Output
Each keyboard is capable of operating in two modes: an unshifted mode and a shifted mode. Up to three keys
on each keyboard are used to select the mode of operation. When a keyswitch is pressed while in the unshifted
mode, the keyboard generates and stores in the keyboard buffer a unique eight-bit code for subsequent transfer
to the terminal. Each keyswitch pressed while in the shifted mode causes the keyboard to generate another
code for transfer to the terminal. This second code may be identical to the code generated 1n the unshifted
mode.
Code Buffer
Each keyboard is capable of buffering a minimum of eight sequentially-entered eight-bit codes for subsequent
transfer to the terminal. Overflow of the code buffer causes the last eight-bit code entered to be overwritten
with the following error code: MSB 10110100 LSB. This error code indicates to the terminal that data was
lost.
N-Key Rollover
Each keyboard provides the capability of N-key rollover. N-key rollover is the ability to sense keyswitch input
in the order the keys are pressed. independent of the order of key release.
Security Keylock
Each keyboard provides a keylock switch. When activated. this keylock prevents the keyboard from generating
eight-bit codes. As a result, the keyboard appears to have no data to transfer when interrogated by the termi-
nal. The keylock switch causes a single eight-bit code to be placed into the keyboard buffer upon completion
of the keyboard power-up sequence. This eight-bit code indicates to the terminal the on (locked) or off (un-
locked) position of the keylock switch. Each change in the on/off position of the keyboard switch during key-
board operation also places an eight-bit code in the buffer indicating to the terminal the new position of the
keylock switch.
The code for the keylock switch when locked is: MSB 10110101 LSB. The code for the keylock when unlocked
(not used) 1$: MSB 11010110 LSB.
In the event that a change in keylock switch position causes a code buffer overflow condition or a change
in keylock switch position occurs when the code buffer is already 1n an overflow condition. the next to last
byte in the code buffer is overwritten with the appropriate keylock switch code and the last byte in the code
buffer is overwritten with an error code.
The LED indicators are accessible to the terminal regardless of the keylock position.
5-1
MT 983/MT 993 Terminal Systems
Section 5
Automatic Key Repeat Function
Each key, when pressed. causes the keyboard to output the assigned code for that key. For most of the keys,
if the key remains pressed for a period exceeding one second, the keyboard initiates an automatic 12-character
per second repeat action. This repeat function is operable only for the last key pressed (excluding shift keys).
TP 110 KEYBOARD
The Burroughs TP 110 alphanumeric keyboard is a general-purpose typewriter-style keyboard to be used with
the MT 983/MT 993. The keyboard consists of a 65-key typewriter keyboard, five function keys, and six indica-
tor lights with a security keylock (see figure 5-1).
LTAI ENQ FORMS LOCAL RCV XMT em
O O O O O О SPC oca RCV XMT
CLEAR|| |! " # $ || % & ( ) || DELI = || > A
HOME || 1 2 3 4 5 6 7 8 9 | $ | — - | —
>
RTAB Q W E R T Y U | O P @ [ ||RETURN
SKIP ||SHIFT 4 5 6 + x
skip feel All SIO FSH ofl ki] Lf;
? \
smiFr || ES Hl Z x ll Cv B Il N Ц s ? ; || per ([SHIFT
EOP ||CHAR _ _ ¡o CHAR DEL
ci? || WET] oer ||
EP1775
Figure 5-1. TP 110 Alphanumeric Keyboard
The keyboard is buffered for rapid manual input of alphanumeric data. An N-key rollover capability allows
entry of data in the order keys are pressed. independent of the order of key release. The automatic repeat-
key function repeats the action of the pressed key until it is released.
The typewriter keyboard is standard U.S. layout with shifted and unshifted modes. The keyboard consists of
the following:
26-character alpha keyboard (upper and lower case)
22 numeric and special character keys
16 editing keys (refer to table 5-1)
5 control keys (refer to table 5-1)
1 space bar
5-2
MT 983/MT 993 Terminal Systems
Section 5
Table 3-1
Keys
CTRL
SHIFT-CTRL
SPCFY
LOCAL
RCV
XMT
CLEAR
HOME
RIAB
RETURN
SKIP
TAB
SHIFT LOCK
SHIFT
ETX
CLR EOP
CLR EOL
CHAR INS
Î
—
=
|
CHR DEL
LINE DEL
LINE INS
All other keys
. Summary of TP 110 and TP 119 Keyboard Edit and Function Keys and Indicators
Functions
Control key; activates control function of terminal and displays CTRL indicator; a valid CTRL
sequence removes it. (Refer to Appendix B.)
Same as CTRL except control function is locked in (displays CTRL indicator). A valid CTRL
sequence leaves it on.
Aligns data comm pointer to cursor, and transmits message indicating cursor position.
Terminates transmission or reception; clears status line, CTRL indicator; sets terminal state to local.
If terminal state is local, changes it to receive-ready, and aligns data comm pointer to cursor.
Aligns data comm pointer to cursor and transmits a message derived from display store.
Clear Page:
Non-forms page: fills page with blanks; leaves cursor at screen home.
Forms page: If bit 3 of 0096 = 1, it fills page with blanks; leaves cursor at
screen home and page in non-forms mode. If bit 3 is 0096 = 0, it fills
unprotected fields with blanks; leaves cursor in first such field.
Home functions:
Non-forms page: moves cursor to screen home.
Forms page: moves cursor to first unprotected field.
Reverse Tab:
Non-forms page: moves cursor to preceding tab stop (if none, to screen home).
Forms page: moves cursor to preceding field.
Carriage Return:
Non-forms page: if bit 0 of 00AQ = 1, stores and displays symbol, moves cursor-to
column 1; if bit 5 of OOAO = 0, moves cursor down.
Forms Page: if bit 6 of O0A0= 1 and cursor location is unprotected, stores ©
moves cursor to column 1. If bit 5 of 00A0 = 1, moves cursor down and right to next unprotected
field.
Search on:
Non-forms page: moves cursor right to next instance of search character (if none, leaves cursor at
screen home).
Forms page: moves cursor right to next instance of search character or next field.
Search off:
Same as TAB, except that — is suppressed.
Tab function:
Non-forms page: if bit 6 of 0096 = 1, stores — (HT): moves cursor right to next
tab stop (if none. leaves cursor at screen home).
Forms page: if bit 6 of 0096 = 1 and cursor location is unprotected, stores — (HT); moves cursor
right to next unprotected field.
SHIFT key with mechanical latch.
Modifies keystroke codes: letter keys yield uppercase codes; other keys are modified as indicated on
keytops.
End-of-Text: if cursor is in protected location of forms page no effect. otherwise, stores ?? (ETX)
and moves cursor as follows:
If bit 7 of 00A0 = 1, moves cursor to column 1 (same line).
If bit 7 of 00A7 = 0, moves cursor to mobile home position.
Clear to end-of-page (if forms page. protected locations are not cleared).
Clear to end-of-line (in forms page. clears to end-of-field).
Character insertion.
Moves cursor up one line.
Moves cursor left one column.
Moves cursor right one column.
Moves cursor down one line.
Character deletion.
Deletes cursor line. shifting succeeding line up (no effect in forms pages).
Inserts blank line at cursor position. shifting the former cursor line and succeeding lines down and
discarding bottom line of page (no effect in forms pages).
Text entry.
5-3
MT 983/MT 993 Terminal Systems
Section 5
(continued)
Table 5-1. Summary of TP 110 and TP 119 Keyboard Edit and Function Keys and Indicators
Indicator
LTAI
ENQ
FORMS
LOCAL
RCV
XMT
Function
Line Terminal Activity Indicator is lit whenever data is transmitted from the host system to any
terminal on the line. Whenever the addressed terminal responds to the host system, that terminal
extinguishes its LTAI indicator. In normal operation, the LTAI indicator blinks due to the data line
activity. An LTAI indicator which remains lit indicates that the terminal is not responding. The
LTAI indicator may be extinguished by pressing the LOCAL key.
The ENQ indicator is lit when a message from the host system is detected by the terminal and
the terminal is not in receive state. The ENQ indicator goes out when the terminal is placed in the
receive (RCV) state or when the operator presses the LOCAL key.
The FORMS indicator is lit when the unshifted FORMS key is pressed or when the terminal enters
forms mode from data comm. FORMS indicator is extinguished upon pressing of the shifted FORMS
key or whenever the terminal leaves forms mode.
The LOCAL indicator is lit by the activation of the LOCAL key or by use of the keyboard when
the terminal is in the receive state with no data being transmitted to the terminal. It is also lit
following the successful completion of data transmission to the terminal unless the programmatic
mode control character (DC1) was present in the received text. The indicator is extinguished when
the terminal is switched to the receive or transmit states.
The RCV (receive) indicator is lit by the activation of the RCV key or by the successful completion
of data transmission from the terminal. The indicator signifies that the terminal is prepared to
receive data. The indicator is extinguished when the terminal is switched to the local or transmit
states.
The XMT (transmit) indicator is lit by the activation of the XMT key and indicates that the terminal
is transmit-ready. The indicator is extinguished when a transmission from the terminal has been
positively acknowledged by the receiving station or when the terminal is switched to local state.
For the effect of keystrokes when CTRL indicator is on, refer to Appendix B.
TP 119 KEYBOARD
The data preparation keyboard resembles a keypunch keyboard in the placement of numerals. Figure 5-2 shows
the layout. It is designed for ease in entering both alphanumeric and numeric data. Numeric data may be en-
tered in both shifted and unshifted condition. The edit keys, function keys, and indicators contained on this
keyboard are described in table 5-1. The data preparation keyboard is recommended for a data entry installa-
tion.
5-4
MT 983/MT 993 Terminal Systems
Section 5
f TA ENO FORMS LOCAL RCV XMT ||cra |spcevliLocaLll rev ll xmr
O O O O O O
_
CLEAR|| | " , $ , & _ g —
HOME || 1 2 3 || 4 5 | 6 7 8 9 2 — :
СНАВ < > # % ( ) 1 2 3 { |
DEL a ll w E | R + || У U | ol Pl @ [ ||RETURN
DEL || 4 5 6 + }
LINE А 5 D F G H J K L : ]
SHIFT || ES || Z X | с у B || м и 8 9 ; SHIFT
EOP |[CHAR SKIP
CLR 1 — — |
cou || ‘NS RTAB|| TAR
EP1776
Figure 5-2. TP 119 Data Preparation Keyboard
5-5
MT 983/MT 993 Terminal Systems
Section 6
SECTION 6
MICRO-DISK FILE STORAGE DEVICES
GENERAL DESCRIPTION
The micro-disk storage devices which may be used with the TP 983/TP 993 terminal system are the Burroughs
model TP 410 and TP 420 file storage modules (FSM). (See figure 6-1.) The storage media is a 5 1/4 inch single-
sided, soft-sectored, flexible (floppy) diskette (see figure 6-2).
EP1701
Figure 6-1. TP 420 File Storage Module
The FSM includes one (TP 410) or two (TP 420) micro-disk drive units. Each disk drive unit accommodates
one diskette. The data storage capacity of a diskette is 80 thousand bytes: therefore. the model TP 410 pro-
vides a storage capacity of 80 thousand bytes and the TP 420 160 thousand bytes.
DISKETTE ORGANIZATION
The diskette is divided into 35 concentric tracks. The FSM uses soft-sector formatting in which each track
is divided into five equal segments (sectors) of 512 bytes each.
DATA FORMATTING
Groups of related data segments are organized into data blocks (catalogs and files). These files and catalogs
can vary in length and are symbolically named. All storage and space management functions (including the
physical location of files) are handled by the FSM.
6-1
MT 983/MT 993 Terminal Systems
Section 6
)
/ 7
INDEX HOLE WRITE PROTECT NOTCH
EP1702
Figure 6-2. Diskette Storage Medium
APPLICABLE DOCUMENTATION
For more detailed information concerning the features and capabilities of the FSM (as well as operating in-
structions), refer to the TP 410/TP 420 Reference Manual, form 1118387.
MT 983/MT 993 Terminal Systems
Section 7
SECTION 7
PRINTERS
GENERAL DESCRIPTION
The printer device which may be used with the MT 983/MT 993 terminal systems is the Burroughs Model
TP 313 journal printer. (See figure 7-1.) This section provides a brief general description of the TP 313 printer.
For more detailed information refer to the TP 300 Reference Manual, form 1121936.
EP1778
Figure 7-1. TP 313 Journal Printer
The printer is a free-standing matrix printer capable of operating with host terminals. The printer simulates
the operation of a line printer. Printing begins when a full line of print has been received. If the message buffer
IS not full, further print data may be received during printing.
A nine-pin print head is used to print on journal paper. Each line of print has a maximum length of 8.25 inches
(209.6 mm.) and a nominal print speed of 90 characters per second. Head motion begins at the left margin,
printing occurs on both the forward and reverse strokes of the carrier.
The TP 313 models provide for printing on a two-ply journal only.
MT 983/MT 993 Terminal Systems
Section 7
PRINTER FEATURES
The major features of the TP 313 printer are identified in the following subparagraphs.
Print Field Density
The standard print density is 12 characters per inch (4.72 characters per cm.). The print density may be pro-
grammatically changed to 16 characters per inch (6.3 characters per cm.), 8 characters per inch (3.15 characters
per cm.), and 6 characters per inch (2.36 characters per cm.). The print density may be changed between two
adjacent print characters within a line.
The maximum number of characters which may be printed on a line at each print density is:
Print Density Characters Per Line
16 CPI 132
12 CPI 99
8 CPI 66
6 CPI 49
Print Speed
The nominal print speed is 90 characters per second, bidirectionally. The line speed depends on the length
of the line printed and the efficiency of turn-around allowed by the print format.
Bidirectional Printing
The print head traverses the paper until all characters on that line are printed. At that point, the printer deter-
mines the most efficient route of travel to begin the next line of print. When printing is completed, the print
head moves to the home position (left margin).
Forms Handler
The forn:s handler mechanism requires pin feed, fan fold, and continuous paper. Single and double ply carbon
or carbonless papers may be used.
Maximur- paper width is 9.5 inches (241.3 mm.). Width between the detachable edges is 8.5 inches (215.9
mm.). Maximum usable print width is 8.25 inches (209.6 mm.).
Vertic: | Line Spacing
The defa. It condition for vertical line spacing advances the paper in 1/6 inch steps (4.24 mm.). Control codes
exist whi.h change the pitch of the vertical spacing to multiples of 1/24 inch (1.06 mm.) steps (maximum line
advance :3 19/24 inch). When vertical line spacing is 1/8 inch or less, overlapping between lines may occur.
The time to advance one line at the standard 1/6 inch vertical spacing is typically 80 msec. The optional 1/8
inch spac ng typically requires 70 msec., 1/4 inch spacing typically requires 90 msec.
Variab:e Page Length
The lengta of page used by top-of-page control is selectable via control codes. A host may select the page
length by specifying the number of lines on a document. The default condition is selectable by a field engineer-
settable switch between 5.5 inches (139.7 mm.) and 11 inches (279.4 mm.).
7-2
MT 983/MT 993 Terminal Systems
Section 7
Out-of-Paper Detection
When printing is approximately 1 inch (25.4 mm.) from the bottom of the last sheet of paper, the Out-of-Paper
signal halts printing on a line boundary. The alert indicator (the audible indicator sounds, if present) is blinking
and the validation chute (if implemented) is closed. Opening the door turns off the indicators.
Printing automatically continues when paper has been properly loaded.
PRINT CHARACTERS
Character fonts are generated by the combination of a basic ROM pattern and print control algorithms. The
algorithms are initiated by control characters.
All fonts are selected by a two-character control string. Once selected. these fonts are always used until a
new selection is made.
The basic matrix pattern is stored in a 2K x 8 ROM located in main memory. A pin-compatible PROM is
available which allows any character font to be specified for specialized markets. Nationalistic character sets
are selected by a specific ROM and a switch configuration which may be modified by a field engineer.
PRINTER STATUS
An eight-bit status word indicates the status of the printer. The lower digit identifies the state of the message
and buffer; the upper digit contains flags that continuously monitor various printer conditions.
PRINTER CONTROLS
Printer operations can be controlled by the operator through the keyboard or by the host system through data
comm controls.
Keyboard Printer Controls
The keyboard entered printer controls are:
Desired Action Keyboard Control Sequence
Print screen data from home to cursor with form feed enabled (CTRL) :
Print screen data from home to cursor with form feed disabled (CTRL) ]
Print unprotected data from home to cursor (CTRL):
Note: (CTRL) designates control function key on keyboard
Data Comm Printer Controls
Printer controls which can be initiated by the host system through data comm are of two types:
|. Printer controls for the terminal to print screen data. | ,
2. Printer controls to print data sent by the host system to control the operation of the printer.
Printing Screen Data |
The data comm controls to print screen data are acted upon by the terminal firmware and are the following:
Data Comm Control
Desired Action Sequence
Print screen data from home to cursor with form feed enabled ESC
Print screen data from home to cursor with form feed disabled ESC |
Print unprotected data from home to cursor ESC :
Note: ESC designates data comm ‘‘escape’’ character (refer to Appendix C)
7-3
MT 983/MT 993 Terminal Systems
Section 7
Controlling Print Operation from the Host System
In the process of printing terminal screen data from the host system as described in the previous paragraph,
it is sometimes necessary to control the operation of the printer. This is done by sending the applicable printer
control characters (described in the TP 313 Reference Manual, form 1121936) to the printer by way of the ter-
minal. In order to make these control characters transparent to the terminal, it is necessary to precede each
sequence of control characters with the following control sequence:
ESC nnn ETX;
Where n can be any number from 0 to 9
The printer control characters which follow this control sequence are displayed on the terminal screen as spe-
cial symbols (refer to Appendix D) and are sent to the printer as part of the screen data when a print operation
is invoked by the host system.
7-4
MT 983/MT 993 Terminal Systems
Appendix A
APPENDIX A
TERMINAL CONFIGURATION
GENERAL
This appendix provides the information required to enter terminal configuration data into the scratchpad mem-
ory of the terminal. (For information concerning the configuration function of the terminal, refer to Section
2 under the heading Configuration Mode.)
SCRATCHPAD MEMORY DISPLAY
Scratchpad memory contents are displayed as 16 pairs of Hex digits. Each pair represents the contents of one
address location in the scratchpad memory. (See figure A-1.) As shown, the entered scratchpad address is dis-
played, followed by the Hex digits representing that address and the next 15 consecutive scratchpad address
locations.
ENTERED
SCRATCHPAD
ADDRESS ua
0080/18 Ai 01 00 ов 27 SF SE
10 30 31 04 08 00 04 04
| 1
0088 008F
0090 0097
ENTERED |
SCRATCHPAD
ADDRESS Na v
0090/00 64 46 OB 4F FF 10 1F
OB 40 00 00 03 50 OF FF
0098 OO9F
EP1779
Figure A-1. Display Format of Configuration Area of Scratchpad Memory
To avoid the possibility of entering data in an area of scratchpad memory beyond the boundaries reserved
for configuration data, always enter address 0080 for changes to the first 16 scratchpad addresses (0080-008F)
A-1
MT 983/MT 993 Terminal Systems
Appendix A
and 0090 for changes to the next 16 scratchpad addresses (0090-009F). To change scratchpad address 00AO,
enter that address and confine changes to the first pair of Hex digits displayed.
Figure A-2 shows the contents of a typical single address location in scratchpad memory and identifies the
most significant and least significant Hex digits as displayed on the screen.
MSD LSD
REGISTER
7 6 5 4 3 2 1 BIT
8 | 4 | 2 | 1 | 8 | 4 | 2 | 1 | BIT WEIGHT
© 0 1 1 1 0 1 q В!МАВУ СОМТЕМТ$
Ne AN ome”
3 A HEXADECIMAL
VALUE
TP1780
Figure A-2. Interpretation of a Typical Scratchpad Memory Byte
ENTERING CONFIGURATION DATA FROM KEYBOARD
The procedure to enter configuration data from the keyboard is given in table A-I.
Step
|. Put terminal in configuration
mode.
2. Display contents of any 16
consecutive scratchpad memory
locations starting at the entered
scratchpad address.
3. Enter desired configuration
data into applicable scratchpad
address location as displayed
on screen.
4. Write screen data back into
scratchpad memory. (This
enables entered configuration
data to be in effect until
terminal is turned off.)
A-2
Table A-1. Terminal Configuration From Keyboard
Action
a. Press CTRL key
b. Enter shifted RWxxxx (where
XXXX represents four-character
password required to enter
configuration mode).
a. Press CTRL key.
b. Enter shifted RH followed by
unshifted hhhh (where hhhh is the
four-digit Hex address of starting
scratchpad location).
a. Position cursor over applicable
Hex digit (most significant four
bits or least significant four bits)
of location to be altered.
b. Enter Hex digit reflecting
desired configuration (Refer to
table A-2).
c. Repeat steps 2 and 3 until all
desired configuration entries have
been made.
a. Press CTRL key.
b. Entered shifted RCxxxx. where
хххх represents four-character
password.
Indication
CTRL is displayed on status line.
Symbol > is displayed in upper left corner of display.
CTRL is displayed on status line.
Contents of selected 16 scratchpad locations is displayed
along with the starting scratchpad address. (See figure A-1).
Entered Hex digit appears at the cursor location.
CTRL is displayed on status line.
Symbol у appears in first column of status line.
MT 983/MT 993 Terminal Systems
Appendix A
(continued)
Step
5. Make configuration changes
fixed through power-off periods.
Table A-1. Terminal Configuration From Keyboard
Action
c. Press LOCAL key.
a. Press CTRL.
b. Enter shifted RPxxxx (where
XXXX represents four-digit
password).
Indication
Screen is momentarily cleared while a reconfiguration
operation takes place. If reconfiguration is successful, six
asterisks are displayed in upper left corner of screen. If
reconfiguration is not successful, an error message is
displayed on the screen.
CTRL is displayed on status line.
The character P is displayed in first column of status line.
If operation is successful, terminal performs a start-up
routine (confidence test) and six asterisks are displayed in
upper left corner of screen. If operation is not successful,
error message is displayed on the screen.
Table A-2. Terminal Configuration Parameters
Remarks
Maintenance aid
Standard operation
Terminal is an operator display
terminal
Terminal is not an operator
display terminal
Home to ETX/home to end-of-
page
Cursor to ETX/home to cursor
(Refer to table A-3)
(Refer to table A-4)
Transmit-to-receive delay value
Lines per page select
Scratchpad
Memory
Address Bits Value Function
0080 0 ] Inhibit parity check
0 Check parity
] 1 Spare
0 Spare
2 1 ODT flag: On
0 ODT flag: Off
3 1 DC1=Programmatic mode control
0 DC1=line erase
4 1 Transmit page in forms
0 Standard forms transmit
5 1 SOH=clear page
0 SOH=NOP
6 1 Point-to-point network
0 Multipoint network
7 1 Synchronous data comm
0 Asynchronous data comm
0081 Baud rate
0082 Clear-to-send delay
0083 0-7 03 3 msec
(Hex)
0-7 16 22 msec
0-7 FF 255 msec
0084 0-7 03 4
(Hex)
0-7 07 8
0-7 08 12
0-7 OF 16
0-7 13 20
0-7 17 24
0-7 IF 32
0-7 2F 48
A-3
MT 983/MT 993 Terminal Systems
Appendix A
(continued)
Table A-2. Terminal Configuration Parameters
Scratchpad
Memory
Address Bits Value Function Remarks
0085 0-7 27 40 Characters per line select value;
(Hex) no other values allowed (must
agree with bit 2 of address
0092)
0-7 4F 80
0086 0-7 7B { Left delimiter select (other
(Hex) symbols acceptable; see figure
D-4 in Appendix D for Hex
codes of other symbols)
0-7 5B [
0087 0-7 7D } Right delimiter select (other
(Hex) symbols acceptable; see figure
D-4 for Hex codes of other
symbols)
0-7 5D ]
0088 0 1 Optional poll/select character 7B/7C
0 Standard poll/select character 70/71
I ] (a and A data transmission numbers 40/41
0 1 and 0 data transmission numbers 30/31
2 1 Circuit 111/126 enabled Required for certain
0 Circuit 111/126 disabled CCITT data sets
3 1 Circuit 116 enabled
0 Circuit 116 disabled
4 1 Internal clear-to-send enabled Refer to address 0082 for delay
value
0 Internal clear-to-send disabled
5 l Transmit-to-receive delay enabled Refer to address 0083 for delay
value
0 Transmit-to-receive delay disabled
6 1 Enable transmit number Option in point-to-point
0 Disable transmit number and multipoint data comm
procedures
7 1 Point-to-point switched For terminals with point-to-point |
0 Point-to-point non-switched data comm capability
0089 0-7 * AD! (Burroughs)/Poll and Select address * Use any address between
ASCII 2,0 and 7,E; used with
AD? as one address
008A 0-7 * AD2 (Burroughs)/Poll and Select address * Use any address between
ASCII 2,0 and 7,E; used with
ADI as one address
008B 0-7 * Group Select (GSL) address (Burroughs)/Device address * Use any address between
ASCII 2,0 and 7,E
008C 0-7 OA 75-300 baud Data comm baud value
09 600-4800 baud
08 9600-38.4K baud
008D Spare
008E 0-7 * Group Poll GPL1 address * Use any address between
ASCII 2,0 and 7.E
008F 0-7 * Group Poll GPL2 address * Use any address between
ASCII 2,0 and 7,E
0090 Spare
0091 0-7 CB 12 lines Total lines per system select
(Hex)
17 24 lines
IF 32 lines
2F 48 lines
SF 96 lines
MT 983/MT 993 Terminal Systems
Appendix A
(continued)
Table A-2. Terminal Configuration Parameters
Scratchpad
Memory
Address Bits Value Function Remarks
0092 0 1 Interpret LF as line feed with automatic carriage return
0 Interpret LF as line feed without carriage return
1 ] Blink cursor Address 0092 bit 5
0 Solid cursor must be enabled for cursor
display
2 ] 80 character/line display
0 40 character/line display Characters per line select (must
3 1 24 line display agree with parameters in address
0085
0 12 line display lines displayed select (must
agree with parameters in address
0093)
4 1 Field overflow inhibit No skip at end-of-field
0 Field overflow allow Skip at end-of-field
5 1 Cursor display inhibited
0 Cursor display enabled
6 1 Keyboard upper case only Prevents keyboard entry of
characters from ASCII columns
6 and 7
0 Lower case enabled For keyboards with lower case
7 1 Spare
0 No RTS hold No delay
0093 0-7 0G 12 lines Lines displayed on screen (must
(Hex)
17 24 lines agree with bit 3 of address
0092)
0094 0-7 End address of display memory Enter most significant byte
07 (Hex) - 1920 character memory
OF (Hex) - 3840 character memory
16 (Hex) - 5760 character memory
0095 0-7 End address of display memory Enter least significant byte
80 (Hex) - 1920 character memory
00 (Hex) - 3840 character memory
80 (Hex) - 5760 character memory
0096 0 1 Interpret DC2 as data comm pointer advance
0 Interpret DC2 as forms enable/disable
] l Interpret FF as clear page and variable tab stops Cleared page 1s data comm
printer page
0 Interpret FF as clear page only
2 ] Invoke vertical tab stops from data comm (VT) or TD 700 emulation
keyboard
2 0 Interpret data comm VT as set horizontal variable tab Horizontal tab stops are set for
stops; keyboard vertical tab controls as advance page entire display memory
3 ] Interpret CLEAR key to erase entire page
0 Interpret CLEAR key to erase only unprotected data Forms mode
4 1 Write ETX into memory at location of data comm pointer
0 Do not write ETX into memory
5 ] Variable tab stops feature enabled
0 Fixed tab stops feature enabled
6 ] Tab-field-identifier option enabled HT (—) character is written into
memory from keyboard
0 Tab-field-identifier option disabled
7 ] Cursor wrap-around inhibit (forms and non-forms keyboard Inhibits keyboard data entry
only) beyond last position on page
0 Cursor wrap-around enabled
0097 0-7 48 End-of-page alarm column detector = column 72
(Hex)
4F End of page alarm column detector = column 80
0098 0-7 0B Set end-of-page alarm row detector = row 12
(Hex)
17 Set end-of-page alarm row detectors = row 24
MT 983/MT 993 Terminal Systems
Appendix A
(continued)
Scratchpad
Memory
Address
0099
009A
009B
009C
009D
009E
009F
00A0
NOTE:
Bits
0-7
“N ое
~~ nh Ln
Value
—
< — © —
Table A-2. Terminal Configuration Parameters
Function
Starting address of display memory CO (Hex) recommended
value; other values allowed
Starting address of display memory 00 (Hex) recommended
value; other values allowed
Spare
Spare
Spare
Hold in receive mode after data comm message
Enter local mode after data comm message
Spare
Spare
Spare
Spare
Starting address of data comm buffer: 00 (Hex)
recommended value; other values allowed
Starting address of data comm buffer 00 (Hex)
recommended value; other values allowed
End address of data comm buffer
(07 (Hex) - 1920 character memory;
OF (Hex) - 3840 character memory)
End address of data comm buffer
(80 (Hex) - 1920 character memory;
DO (Hex) - 3840 character memory)
Write data comm HT into memory during tab operations
Do not write data comm HT into memory
Unused
Automatic cursor advance after data comm ETX
No cursor advance after data comm ETX
Interpret data comm CR as carriage return without line
feed
Interpret data comm CR as carriage return with line feed
Write data comm CR into memory
Do not write data comm CR into memory
Interpret keyboard CR (return key) as a carriage return
without line feed
Interpret keyboard CR as carriage return with line feed
Write keyboard CR into memory
Do not write keyboard CR into memory
Line-at-a-time transmission
Standard transmission
Remarks
Enter most significant byte
Enter least significant byte
Enter most significant byte
Enter least significant byte
Enter most significant byte
Enter least significant byte
Ignored if ETX not stored (refer
to scratchpad address 0096, bit
4)
Ignored if ETX not stored (refer
to scratchpad address 0096, bit
4)
Line home to cursor
Transmission point (mobile
home)
The RTS hold delay is used with older style data sets (including Bell 202 C and D). If set, the terminal
holds RTS (request-to-send) high for an additional three bit times to assure that the data from the terminal
is passed through the data set. Newer style data sets (Bell 202 S and T. Bell 209) and direct-connect net-
works do not require any RTS hold delay.
ENTERING CONFIGURATION DATA FROM HOST SYSTEM (DATA
COMM)
The terminal may be reconfigured from the host system provided that the terminal 15 configured SO that com-
munication through data comm is possible. The data comm controls used for terminal configuration are de-
scribed in the following subparagraphs.
A-6
MT 983/MT 993 Terminal Systems
Appendix A
Table A-3. Baud Rate Conversion
Baud Rate Hex Code for Address 0081
75 41
110 7E
150 Al
300 D]
600 Al
1200 DI
1800 El
2400 E9
4800 FS
9600 Al
19.2K DI
38.4K (asychronous only) E9
Table A-4. Clear-to-Send Delay
Delay in
Type of Communications Milliseconds Hex Code for Address 0082
V23 (four-wire), 1200 or 600 baud 16/200 10/C8
V23 (two-wire), 1200 or 600 baud 200 C8
V21 and Bell 202 series 50 32
Bell 103 series 255 FF
Burroughs TA 713 16 10
Burroughs TA 783 16 10
TDI or BDI 0 00
Notes:
I. Internal clear-to-send delays are not required for use with data sets. Data sets provide clear-to-send
delays appropriate for its designs. To simulate data set clear-to-send delays when needed. use the delay
as listed in this table. The delay circuit is enabled by loading a logic 1 into Address 0088 bit 4.
2. If no internal CTS signal is required, disable by loading a logic 0 into address 0088. bit 4.
3. Internal CTS value is minimum delay if using data set interface. If internal CTS is shorter than data
set CTS. it waits for data set. If data set CTS is shorter than internal CTS, it waits for internal value.
ESC RT Sequence
This sequence in an incoming data comm message enables the host system to read the terminal scratchpad
memory. The ESC RT sequence is acted upon immediately, that is, as soon as the message interpreter recog-
nizes it. The rest of the message is never interpreted.
The full sequence is ESC RT aaaacc, where aaaa represents four Hex-digit characters denoting the starting
scratchpad address and cc represents two Hex-digit characters which denote the number of scratchpad bytes
to be transmitted. The scratchpad bytes are scanned in ascending order; for each byte, the two characters
representing 1t in accordance with the customary Hex unpacking, are loaded into the data comm buffer. If
any part of the address span specified by this sequence falls outside the scratchpad area of memory (specif-
ically 0000-007F or beyond 018C), the appropriate number of 00 Hex digit pairs is automatically entered.
ESC RH Sequence
This sequence enables the host system to enter configuration data into the scratchpad memory.
The full sequence is ESC RH abc which is interpreted as follows:
I. “a” represents the four-digit Hex address used to identify the starting scratchpad memory address at
Which the host system begins to write configuration data.
2. ‘‘b’’ represents the two-character Hex byte count used to identify the number of memory bytes to be
reconfigured.
A-7
MT 983/MT 993 Terminal Systems
Appendix A
3. “Cc” represents the configuration data to be written into the area of scratchpad memory selected in item
|. This data can be up to 254 bytes long.
ESC RC Sequence
This sequence is used to initiate a restart operation following an ESC RH sequence. The ESC RC sequence
enables the terminal to be operated with the changed configuration data, thus allowing the changed data to
be checked for accuracy before it is transferred to EAROM. Provided that no errors are found in the values
loaded into the scratchpad memory, the terminal responds to the host system with a message containing SIX
asterisks.
ESC RP Sequence
This sequence is used to write the updated scratchpad memory data into the EAROM to change the fixed
terminal configuration data. This operation allows the terminal configuration changes to survive power-off pe-
riods of the terminal.
If this operation is successful, the terminal is returned to the local state.
MT 983/MT 993 Terminal Systems
Appendix B
APPENDIX B
LOCAL KEYBOARD CONTROL (CTRL)
GENERAL
SEQUENCES
This appendix describes control functions which may be invoked from the keyboard by use of the CTRL key.
Table B-1 is a composite list of these control functions for quick reference. The following is a description of
the control functions.
Control
CTRL A
CTRL B
CTRL E x
CTRL H x
CTRL 1
CTRL M
CTRL N
CTRL O
CTRL P
CTRL Q
CTRL RA (shifted)
hhhh (unshifted)
CTRL RCxxxx
(shifted)
Function
Turns search function on.
Interchanges the cursor line with the line immediately below it. Cursor moves
down with line.
Designates the search character; where x can be any text key.
Used to designate a highlight operation; where x can be any valid highlight
code. Also used to send special data comm control characters to host system
where x is the key which represents the desired data comm character. (See
figure D-3 in Appendix D.)
Sets the video presentation to positive (green characters on a dark background)
video which is the terminal’s normal presentation.
Initiates a roll page down operation. Displayed page rolls down one line each
time this control sequence is entered (cursor remains stationary).
Initiates a roll page up operation. Displayed page rolls up one line each time
this control sequence is entered (cursor remains stationary).
Clears variable tab stops, if applicable.
Complements variable tab stop for present cursor location provided that the
variable tab stops configuration option is invoked. (Sets tab if not already set;
resets tab if already set.)
Puts the cursor page to the non-forms mode; cursor is moved to the home
position of the cursor page. If bit 3 of system register 0096 is set to a |, page
is cleared.
If configuration mode is set, displays contents of 16 consecutive scratchpad
memory locations (in ASCII) beginning at the address signified by the numeric
value entered in the hhhh segment of the control sequence (for example,
RA0090). This control sequence 1s intended for use by a Burroughs field
engineer to alter fixed message data and terminal password.
Stores back into the scratchpad memory updated configuration data displayed on
the screen. (Used for temporary configuration changes.) The terminal password is
entered in the xxxx segment of the control sequence. The details of the process
depend on which of the display-scratchpad operations (ASCII or Hex) has been
most recently invoked (if neither has been invoked since the most recent
password sequence, the scratchpad memory restore operation does nothing). In
the display Hex case, 16 consecutive pairs of Hex digits are packed into
characters and stored; if any character other than a Hex digit is encountered,
the process terminates prematurely. In both cases, the starting scratchpad
address 1s the one used in the most recent display scratchpad operation,
regardless of how the address displayed on the screen may have been edited.
B-1
MT 983/MT 993 Terminal Systems
Appendix B
(continued)
Control
CTRL RH (shifted)
hhhh (unshifted)
CTRL RLxxxx
(shifted)
CTRL RPxxxx
(shifted)
CTRL RWxxxx
CTRL S
CIRL T
CTRL U
CTRL V
CTRL W
CTRL Y
CTRL ;
CTRL |]
CTRL:
B-2
Function
Moreover, the data to be stored is taken from the positions on the screen
where the display scratchpad operation wrote it. This must be remembered
when editing the display data. Finally, when the last piece of data has been
stored, an ACK (symbol) is displayed on the status line in the leftmost blank
position. If the operation is terminated by an invalid Hex digit, a NAK (symbol)
appears instead. If the LOCAL key is pressed after a scratchpad memory
restore operation, the screen is cleared and a reconfiguration operation is
attempted. If it is successful, the configuration mode flag is cleared and a
display of * * * * * * ig written in the home position of page 1. The data comm
transceiver goes on-line. If it is unsuccessful, an error message is written in
page | (see section 2 for a list of error messages), the configuration mode
remains set, and the data comm transceiver remains off-line.
If configuration mode is set, displays contents of 16 consecutive scratchpad
memory locations (in hexadecimal), beginning at the scratchpad address signified
by the numeric value entered in the hhhh segment of the control sequence (for
example, RH0090). The screen is cleared and the scratchpad memory data is
displayed in upper left corner of screen. Refer to Appendix A for more detailed
information.
If configuration mode is set, displays contents of the error log. Enter terminal
password in the xxxx segment of the control sequence.
If configuration mode is set, writes scratchpad memory contents into EAROM
to change the fixed configuration data to reflect new data entered into the
scratchpad memory. Enter terminal password for the xxxx segment of the
control sequence. At the end of this process, a P is displayed in the leftmost
position of the status line and the terminal enters its startup routine.
Puts the terminal in configuration mode. RW must be shifted. Enter the terminal
password (must match exactly) in the xxxx segment of the control sequence.
The data comm transceiver goes off-line and the search function (if active) 1$
disabled. The cursor is displayed in the upper left corner of page 1 and the
symbol > is displayed at the cursor location. As long as the configuration mode
is set, the XMT, RCV, and SPCFY keys are disabled.
Turns the search function off.
Enables the entry of lowercase characters from the keyboard. (Sets bit 2 of
system register 0092 to 0.)
Sets video presentation to negative (dark characters on a green background)
video.
Interchanges the cursor line with the line immediately above it. Cursor moves
up with the line.
Puts the cursor page in the forms mode (provided that all requirements to enter
forms mode are met). Cursor is moved to the first unprotected field.
Disables keyboard entry of lowercase characters. (Keyboard becomes all upper
case.) Sets bit 2 of system register 0092 to a |.
Enables a printer operation where screen data is printed out on the printer and
form feed 1s enabled in the printer.
Enables a printer operation where screen data is printed out on the
printer and form feed is not enabled in the printer.
Enables a printer operation where the unprotected data of a page (forms mode)
is printed out on the printer and form feed is enabled in the printer.
MT 983/MT 993 Terminal Systems
Appendix B
(continued)
Control
CTRL ?
CTRL 1
CTRL |
CTRL >
CTRL —
CTRL >
CTRL CHAR/INS
CTRL CHAR/DEL
CTRL carriage return
CTRL HOME
CTRL space C CTRL
CTRL space D CTRL
CTRL space E CTRL
CTRL space H CTRL
CTRL space J CTRL
CTRL space K CTRL
Function
Complements the horn enable flag. (If horn enabled; disables horn: if horn
disabled, enables and sounds horn.)
Initiates a scroll display-memory up operation. Display memory data moves up
one line through the screen window for each time this control sequence is
entered. (Cursor remains stationary.)
Initiates a scroll display-memory down operation. Display memory data ts moved
down one line through the screen window each time this control sequence 1s
entered. (Cursor remains stationary.)
Moves cursor to the home position of the next page or moves cursor down to
the next vertical tab stop. depending on terminal configuration.
Moves cursor to the home position of the previous page or moves the cursor
up to the previous vertical tab stop, depending on terminal configuration.
Moves the cursor to the current location of the data comm pointer.
Initiates a character insert operation on a page basis. (When a character 1s
inserted, all the following characters on the page are moved one place to the
right and down as required. The last character of the page 1s lost.)
Initiates a character delete operation on a page basis. (When a character 1s
deleted, all following characters on the page are moved up and to the left as
required.
Initiates a carriage return operation without storing (displaying) the carriage
return symbol (V).
Sets the mobile home parameter to the line and column of the current cursor
location.
Clears the cursor page and displays the resident character set in the first 128
character positions of the screen.
Perform terminal restart. (Confidence test 1s performed and scratchpad memory
IS loaded from EAROM:)
Performs repetitive memory test. Terminal enters restart mode when any key 1s
pressed. (Used for maintenance only.)
Sets data comm bit rate to 600 baud and restarts data comm. This control
sequence also makes the following configuration changes to the system registers:
Sets:
register 0081 to equal Al (Hex)
bit 3 of register 0088 to a 1
bit 2 of register 0088 to a 0
Sets data comm bit rate to 1200 baud and restarts data comm. This control
sequence also makes the following configuration changes to the system registers:
Sets:
register 0081 to equal DI (Hex)
bit 3 of register 0088 to al
bit 2 of register 0088 to a |
Sets data comm bit rate to 1800 baud (asynchronous) or 2400 baud
(synchronous) and restarts data comm. This sequence also makes the following
configuration changes to the system registers:
If terminal is configured for asynchronous. sets register 0081 to equal El (Hex).
If terminal 1s configured for synchronous, sets register 0081 to equal E9 (Hex).
Sets bit 3 of register 0088 to a 0.
Sets bit 2 of register 0088 to a 0.
MT 983/MT 993 Terminal Systems
Appendix B
(continued)
Control
CTRL space M CTRL
CTRL space V CTRL
CTRL < cr
CTRL nn XMT
Control Sequence
CTRL ]
CTRL:
CTRL ;
CTRL >
CTRL < cr
CTRL ?
CTRL A
CTRL B
CTRL E x
CTRL H x
CTRL 1
CTRL M
CTRL N
CTRL O
CTRL P
CTRL Q
CTRL R ()
CTRL S
CTRL T
CTRL U
CTRL V
CTRL W
CTRL Y
CTRL |
CTRL |
CTRL —
CTRL <
CTRL (CHAR/DEL)
CTRL (CHAR/INS)
CTRL (carriage return)
CTRL (HOME)
CTRL space C CTRL
CTRL space D CTRL
CTRL space E CTRL
CTRL space H CTRL
CTRL space J CTRL
CTRL space K CTRL
CTRL space M CTRL
CTRL space V CTRL
CTRL nn XMT
Function
Fills entire screen with the letter E.
Clears the cursor page and displays firmware version number in the upper left
corner of the display.
Moves cursor to the column (c) and row (r) specified. Cursor position 1s not
limited to screen data but can be positioned anywhere in display memory (row
1 through row 96). See figure D-4 in Appendix D for information concerning the
keyboard graphic character to be entered for the desired column/row values.
Loads data comm character sequence ESC nn ETX into buffer for transmission
to host system. (The letters nn represent the special data digits to be sent to
the host system; n can be any number from 0 to 9.)
Table B-1. Keyboard Control Sequences
Function
Print screen data (no form feed)
Print unprotected data
Print screen data (form feed enabled)
Align display cursor to data comm pointer
Move cursor to column (c) and row (r) specified. (Column and row values are given in table D-4.)
Sound audible alarm
Enable search mode
Line movement down
Set search character equal to value of x
Enable special symbol or highlight function signified by value of x, where x stands for key
associated with desired special symbol or highlight. (See figure D-3 in Appendix D for list of special
symbol keys.)
Negative video off
Roll down
Roll up
Clear all variable tab stops
Set or reset a tab stop
Forms disable
CTRL R sequences are used for terminal configuration (refer to Appendix A)
Disable search mode
Enable lower case from keyboard
Negative video on
Line movement up
Forms enable
Disable lower case from keyboard
Scroll up
Scroll down
Page advance
Page back
Character delete by page
Character insert by page
Carriage return without related symbol displayed
Mobile home parameter equal to cursor location
Display resident character set
Initiate system confidence test
Repetitive memory test
Data rate: 600 bps
Data rate: 1,200 bps
Data rate: 2,400 bps if synchronous, 1.800 bps if asynchronous
Fill screen with E characters
Display firmware version number
Transmit ESC nn ETX sequence to host system; where n can be any number from 0 to 9.
MT 983/MT 993 Terminal Systems
Appendix C
APPENDIX C
DATA COMM CONTROL CHARACTERS
AND SEQUENCES
GENERAL
This appendix describes the control characters and sequences which may be invoked from the host system
through the data comm interface. Table C-1 defines the data comm control characters and table C-2 describes
the control sequences invoked by use of the ESC (escape) control character.
Table C-1. Data Comm Control Characters
Sequence or Character ASCII Coding
Column Row Definition of Terminal Response
NUL 00 Time Fill
SOH 01 Start-of-Heading
STX 02 Start-of-Text
ETX 03 End-of-Text
EOT 04 End-of-Transmission
ENQ 05 Enquiry
ACK 06 Acknowledge
BEL 07 Sound Audible Alarm (unless disabled by ESC ?)
BS 08 Move data comm pointer one position to the left
HT 09 Move data comm pointer to next tab stop
LF 0A Move data comm pointer down to same column, next row
VT 0B Complement variable tab stop for present location of data comm
pointer (provided variable tab stop configuration option is
invoked)
FF оС Home Cursor, Clear Display
CR OD Initiate carriage return (Display Y )
SO OE Initiate Reverse Video Highlight (Display Space)
SI OF Initiate Underline Highlight (Display Space)
DLE 10 Display DLE symbol
DCI 11 Set Hold-In-Receive flag or clear to end of line
DC2 12 Move data comm pointer one position to the right or complement
forms mode
DC3 13 Move data comm pointer up to same column, next row
DC4 14 Move data comm pointer to the home position
NAK 15 Not-Acknowledge
SYN 16 Display SYN symbol
ETB 17 Display ETB symbol
CAN 18 Initiate Blink Highlight (Display Space)
EM 19 Initiate Secure Video Highlight (Display Space)
SUB 1A Initiate Bright Video Highlight (Display Space)
ESC IB Designates control sequence (refer to table C-2)
FS IC Display MP (Signified beginning of a protected field where data is
transmitted unchanged)
GS 1D Display A (Signifies beginning of a GS unprotected field)
RS IE Display « (Signifies end of unprotected field; beginning of
protected field
US IF Display © (Signifies beginning of a US unprotected field)
MT 983/MT 993 Terminal Systems
Appendix C
ESC
ESC
ESC
ESC
ESC
ESC
ESC
ESC
ESC
ESC
ESC
ESC
ESC
ESC
ESC
ESC
ESC
ESC
ESC
ESC
ESC
ESC
ESC
ESC
ESC
ESC
ESC
ESC ©
ESC
ESC
ESC
ESC
ESC
Table C-2. Description of Data Comm Escape Control Sequence
Notes: Unlike CTRL sequences; ESC sequences that include letters require them to be in up-
per case. Lower case letters in this table have the following significance:
h, k = hexadecimal digit (O,....9.A.....F)
p.c.r = character in the ASCII subset (space.....DEL)
x = character
Escape Character
C
D
E
F
TOZEZ- A =
RThhhhkk
RAhhhhkk
RHhhhhkk
RC
RP
RS kk
RL
S
T
W
(a
%
ESC .
C-2
Function
Move data comm pointer one position to the right.
Set mobile home line and column to the line and column of the data comm
pointer.
Turn search function on.
If data comm poinier and keyboard cursor are in the same page. turn search
function off and set search character equal to 1.
Clear from data comm pointer to end-of-page.
Clear from data comm pointer to end-of-line.
Insert a blank line at data comm pointer.
Delete the data comm pointer line.
Set video presentation of data comm pointer page to negative video.
Set video presentation of data comm pointer page to normal (positive) video.
Delete (by page) the data comm pointer character.
Transmit to host machine kk bytes of data from scratchpad memory beginning
with address hhhh.
Store next kk bytes of message (ASCII data) into scratchpad memory, beginning
at address hhhh.
Interpret next kk characters of message as Hex digits; pack pairs of digits into
bytes and store them into scratchpad memory beginning at address hhhh.
Perform configuration operation.
Copy scratchpad memory contents into EAROM and start terminal.
Clear status line and copy next kk bytes of message into it.
Transmit contents of error log to host system.
Roll data comm pointer page up.
Roll data comm pointer page down.
Transform data comm pointer page to forms mode (provided transformation is
valid), and move data comm pointer to first unprotected field.
Set forms mode of data comm pointer page off.
Disable keyboard entry of lowercase characters (sets bit 6 of system register 0092
to 1).
Enable keyboard entry of lowercase characters (sets bit 6 of system register 0092
to 0).
Insert (by line) a blank at the data comm pointer location.
Insert (by page) a blank at the data comm pointer location.
Delete (by line) the character at the data comm pointer location.
Move data comm pointer to (column c, row r) of the page it is on. (Refer to table
D-4 in Appendix D for information concerning the ASCII code to be entered for
the desired column/row values.)
Move data comm pointer to the home position of page n. Refer to table D-4 for
the ASCII code to be entered for desired page (n).
If variable tab stop option is in effect, clear tab stops.
Move keyboard cursor to the current location of the data comm pointer.
Set transmit page flag to initiate transmit operation.
Set search character equal to x.
If variable tab stop option is in effect, complement the tab stop corresponding to
the current data comm pointer column number.
MT 983/MT 993 Terminal Systems
Appendix C
(continued)
Table C-2. Description of Data Comm Escape Control Sequence
Notes: Unlike CTRL sequences; ESC sequences that include letters require them to be in up-
per case. Lower case letters in this table have the following significance:
h, k = hexadecimal digit (O,....9.A,....F)
p,c,r = character in the ASCII subset (space,...,.DEL)
x =character
Escape Character Function
ESC < Move the data comm pointer line down.
ESC > Move the data comm pointer line up.
ESC ? Beep horn (audible alarm) if enabled.
ESC ; Print screen data from home to cursor with form feed enabled.
ESC : Print unprotected data from home to cursor with form feed enabled.
ESC | Print screen data from home to cursor, no form feed.
ESC” x Used to designate highlight operation where x can be any valid highlight code. Also
used to send data comm control characters to terminal without their control functions
being invoked.
ESC space D Terminal restart (confidence test, reconfiguration from EAROM)
ESC space V Transmit firmware version number to host system.
ESC space C Write resident character set in first 128 locations of page. (Data comm pointer is
left in the lower position of page).
MT 983/MT 993 Terminal Systems
Appendix D
APPENDIX D
REFERENCE DATA
Ь; — — — — O о | |
be —> о 0 | | O 0 |
bs > | О
ba { b3 | b2 | by COL
41431417 y № >| 0 | 2 3 4 5 7
о | о | © | о 0 NUL DLE SP 0 @ Р Р
о | © | © |! | SOH DC | | | А Q q
о | оО Г | о 2 STX DC 2 8 2 B R r
ojo | + | I 3 ETX DC 3 # 3 С 5 $
о | то |0 4 EOT DC 4 $ 4 D T t
ol 1 jo] 5 ENQ NAK % 5 E U u
olilito 6 ACK SYN a 6 F V v
O || || 1 7 BEL ETB 7 G W м
г Го | о | о 8 BS CAN ( 8 H X x
i O | OTI! 9 HT EM ) 9 I Y y
ГО | 1 | о А LF SUB X J Z z
blo | 1 B Ут ESC . K C {
|| 1 j0|0O С FF FS < L \
ı|ılolı D CR GS — = M ] }
| | | O E so RS > N AN
1j 1 | 1 | 1 F SI US / P O — DEL
ЕР1408
Figure D-1. Standard U.S. ASCII Chart
MT 983/MT 993 Terminal Systems
Appendix D
DEC HEX DEC HEX DEC HEX
1 00 25 18 4g 30
2 01 26 19 50 31
3 02 27 1A 51 32
4 03 28 1B 52 33
5 04 29 1C 53 34
6 05 30 1D 54 35
7 06 31 1E 55 36
8 07 32 1F 56 37
9 08 23 20 57 38
10 09 34 21 58 39
11 OA 35 22 59 3A
12 OB 36 23 60 3B
13 OC 37 24 61 3C
14 OD 38 25 62 3D
15 OE 39 26 63 3E
16 OF 40 27 64 3F
17 10 44 28 65 40
18 11 42 29 66 44
19 12 43 2A 67 42
20 13 44 2B 68 43
21 14 45 2C 69 Ца
22 15 46 2D 70 45
23 16 47 2E 71 LE
24 17 48 2F 72 47 96 SF
Figure D-2. Decimal to Hexadecimal Conversion Chart
D-2
MT 983/MT 993 Terminal Systems
Appendix D
USACII Keyboard Video USACH Keyboard Video
NUL SPACE 0 DLE 0 a
SOH ! Г DC1 1 0
STX " 1 DC2 2 0
ETX # Y DC3 3 0
EOT $ J DC4 4 0
ENQ % В МАК 5 J
ACK 8 J SYN 6 Л
BEL ‘ a ETB 7 À
BS ( 1 CAN 8(blink) 8
HT ) > EM 9(secure) +
LF * - SUB :(bright ç
VT + J ESC : 0
FF | $ FS < 9
CR v GS = a
SO (neg.vid.) 8 RS > q
Si /(underline) 0 US 9 D
Figure D-3. Special Symbols Chart
MT 983/MT 993 Terminal Systems
Appendix D
Cursor Cursor Cursor
Position Position Position
COLM/ Graphic USASCII COLM/ Graphic Ñ USASCII COLM/ Graphic USASCII
ROW Character Code ROW. Character Code ROW Character Code
1 space 20 33 @ 40 65 60
2 ! 21 34 A 41 66 a 61
3 ” 22 35 В 42 67 b 62
4 = 23 36 C 43 68 С 63
5 $ 24 37 р 44 69 а 64
6 % 25 38 Е 45 70 е 65
7 & 26 39 Е 46 71 f 66
8 27 40 G 47 72 g 67
9 ( 28 41 H 48 73 h 68
10 ) 29 42 I 49 74 i 69
11 * 2A 43 J 4A 75 J 6A
12 + 2B 44 K 4B 76 k 6B
13 , 2C 45 L 4C 77 1 6C
14 — 2D 46 M 4D 78 m 6D
15 . 2E 47 N 4E 79 n 6E
16 / 2F 48 O 4F 80 о 6F
17 0 30 49 Р 50 81 р 70
18 1 31 50 Q 51 82 q 71
19 2 32 51 К 52 83 r 72
20 3 33 52 S- 53 84 $ 73
21 4 34 53 T 54 85 t 74
22 5 35 54 U 55 86 u 75
23 6 36 55 V 56 87 у 76
24 7 37 56 W 57 88 w 77
25 8 38 57 X 58 89 X 78
26 9 39 58 Y 59 90 y 79
27 3A 59 Z SA 91 Z 7A
28 ; 3B 60 f 5B 92 | 7B
29 < 3C 61 \ 5C 93 ; 7C
30 = 3D 62 ] 5D 94 | 7D
31 > 3E 63 A SE 95 ~ 7E
32 ? 3F 64 — SF 96 DEL TF
Figure D-4. Programmable Cursor Select Values
INDEX
C
CAPABILITIES, interface 1-3; description of 1-4
CHARACTER, format 1-4; insert 1-9; delete 1-10
CHARACTERISTICS, system 1-3; keyboard 5-1; microdisk 6-1; printer 7-1
COMMUNICATIONS, with host system 3-1; procedures 3-2; interface 3-2; asynchronous 3-4; synchronous 3-4;
with peripherals 4-1 |
CONFIGURATION, system 1-3; control 1-7; mode 2-11; default 2-12; from keyboard A-2; from host system
A-6; parameters A-3
CONTROLS, operator 1-14; keyboard 1-14; printer 7-3; data comm interface C-1
CURSOR, description of 1-8; movement of 1-11
D
DISPLAY, description of 1-2; characteristics 1-4; negative video 1-8; memory 2-1; store process 2-9
E
EDIT, functions 1-9; controls 1-16
ERROR, messages 1-7; log 2-13
F
FEATURES, list of 1-6; page formatting 1-7; status display line 1-7; negative video 1-8; cursor display 1-8;
data highlighting 1-8; optional microdisk 6-1; optional printer 7-2; terminal configuration A-1
FORMS, capability 1-5; delimiters 1-5; description of 2-10; selection of 1-15
FUNCTIONS, editing 1-9; search 1-13; maintenance 2-12; keyboard control (CTRL) B-1
H
HIGHLIGHTING, description of 1-8; underline video 1-9; blinking video 1-9; secure video 1-9; bright video
1-9; reverse video 1-9; how to initiate 1-15
HOST, method of interface 1-3; interface communication procedures 3-2; data comm interface 3-1; control of
printer 7-4; terminal configuration from A-7; control of terminal from C-1
I
INTERFACE, types of 1-3; data communications 3-2; serial 1/O 4-1
K
KEYBOARD, types of 1-2; operator controls 1-15; description of 5-1; functional characteristics 5-1; terminal
configuration from A-2; control (CTRL) function B-1
L
LINES, format of display 1-2; deletion and insertion of 1-10; movement up/down 1-10
M
MAINTENANCE, functions 2-12; observable indications 2-13
MEMORY, allocation of 2-1; display 2-1; scratchpad 2-1
MESSAGE, synthesizer 2-5; keyboard initiated display memory 2-6; host system initiated display memory 2-7;
keyboard initiated numeric 2-7; specify 2-7; firmware level 2-7; reconfiguration response and successful
restart 2-7; error log 2-7
MICRODISK, general description of 6-1; applicable documentation 6-2
MODE, description of 1-4; forms 2-10; configuration 2-11
P
PAGE, forms 1-5; formatting 1-7; definition of 1-7; number 1-8
PASSWORD, definition of 2-12; default 2-12; use of A-2
PERIPHERALS, optional 1-2; interface with 4-1; microdisk 6-1; printers 7-1
PRINTER, initiate from keyboard 1-18; general description of 7-1; features 7-2; characters 7-3; status 7-3; con-
trols 7-3; initiate from host system C-3
PROCESS. main 2-2; data comm interface 2-7; keyboard interface 2-9; display store 2-9; video 2-10
PROCESSES, major 2-2; description of 2-2
R
RECEIVE, description of 1-6; select from keyboard 1-15; operation of 2-2
S
SCRATCHPAD, definition of 2-1; description of 2-11; interpretation of A-1; keyboard access to A-2; host sys-
tem access to A-6
SCREEN, format 1-2; capacity 1-4; window 1-7
STATES, identification of 1-6; local 1-6; receive 1-6; transmit 1-6
STATUS line 1-7; reporting 1-7
T
TAB, function 1-12; variable 1-12; fixed 1-12; forward 1-12; reverse 1-13; vertical 1-13; initiate from keyboard
1-17
TRANSMIT, description of 1-6; operation of 2-2; select from keyboard 1-15
V
VIDEO presentation 1-4; negative 1-8; secure 1-9; bright 1-9; reverse 1-9; process 2-10
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