Peripheral Devices

Peripheral Devices
Peripheral Devices
What’s Inside and on the CD?
This chapter provides an overview of the most popular peripheral devices for personal computers. It
begins with standard input devices—your computer’s keyboard and mouse—and then takes a look at
some specialized input devices including trackpads, digital cameras, and joysticks. In the FAQs about
output devices, you’ll learn about computer display devices and printers. Specialized output devices,
such as voice synthesizers and plotters, are also explained.
Peripheral devices can be connected to a computer system in a variety of ways. You’ll find out which
technologies provide the easiest connections.
The chapter winds up with an FAQ about purchasing components for a computer system. Handy tips
will help you know what to look for when shopping for a computer, software, and peripheral devices.
What is a peripheral device?
What are the options for standard input devices?
What are the options for specialized PC input devices?
What are the most popular display technologies?
What are the most popular printer technologies?
What are the options for specialized output devices?
How do I connect peripheral devices to my computer?
How do I select components for my computer system?
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Chapter 2 Peripheral Devices
FAQ What is a peripheral device?
The term peripheral device refers to any input or output component that connects to a
computer’s system unit. On a personal computer, standard peripheral devices include
a keyboard, mouse, display unit, and printer. A wide variety of specialized peripheral
devices for playing games, monitoring home security, capturing video images, and all
kinds of other activities are also available for your personal computer. You’ll learn more
about personal computer peripheral devices later in the chapter.
Specialized peripheral devices are a key component of many large-scale computer
systems. High-speed printers are instrumental in addressing mass-mailing envelopes
based on customer lists stored in a database. Mass mailings legitimately assist utility and
credit card companies with monthly billing, but unfortunately also generate mountains of
junk mail from advertisers and sweepstakes solicitors.
Banks use high-speed optical character readers and other sophisticated imaging
peripherals to read and sort millions of paper checks at high speed without halting on
creased, torn, or stapled checks. The check amount and account number are read
and fed into the bank computer system. Check images generated by any bank can be
transmitted to the Federal Reserve and the issuing bank for verification and archiving.
Some manufacturing firms use computer-controlled robots to carry out tasks such as arc
welding, circuit board assembly, and painting. These robots, which are often part of an
assembly line, can be reprogrammed as necessary to accommodate new and updated
Overnight shipping firms, such as UPS and FedEx, use handheld scanning devices to
keep track of package deliveries. The shipping label for each package contains a bar
code. When a package is delivered, the bar code is scanned and the scanning device
automatically adds a date and time stamp. The package recipient’s signature can be
collected on a pressure-sensitive input pad, and stored in memory until the driver returns
to base and transfers the scanner’s contents to the company’s main computer system.
Retail stores use UPC scanners at staffed
and self-checkout lanes (shown in Figure
2-1). As each item is scanned, its price
is pulled from the store’s main computer
database. At the same time, the inventory
count for that item is decreased by one to
maintain an up-to-date list of products in
All of these devices—high-speed
printers, optical character readers,
computer-controlled robots, package
scanners, and UPC scanners—can be
considered peripheral devices. Although
they are not typically part of personal
computer systems, these peripherals are
important components of large, enterprise
computer systems and underscore the
key role that digital devices play in
business and industry.
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Chapter 2 Peripheral Devices
FAQ What are the options for standard input devices?
Most personal computer systems include a keyboard and a pointing device for basic data
input. These are the tools you use most often when entering data, issuing commands,
and manipulating on-screen objects.
The keyboard is the most important input device on desktop and notebook computers,
but you can even find tiny keyboards on handheld devices—entering text and numbers
is required for just about every computing task. The design of most computer keyboards
is based on the typewriter’s QWERTY layout. This unusual arrangement of keys was
not designed to maximize typing speed, but to keep a typewriter’s mechanical keys from
jamming. Computers inherited this layout because of its familiarity to millions of typists.
In addition to the basic typing keys (Figure 2-2), computer keyboards can include an editing
keypad with arrow keys to efficiently move the screen-based insertion point. They also
include a collection of function keys designed for computer-specific tasks, such as putting
the computer into sleep mode, adjusting screen brightness, and using a second display
screen. Many computer keyboards also include a calculator-style numeric keypad.
Function keys
Arrow keys
A pointing device allows you to manipulate an on-screen pointer and other
screen-based graphical controls. The most popular pointing devices for personal
computers include mice, trackballs, pointing sticks, trackpads, and joysticks.
A standard desktop computer includes a mouse as its primary pointing device. Many
computer owners also add a mouse to their notebook computers because it is easier to
use than the notebook’s standard trackpad.
On/off switch
Scroll area
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A trackpad (also called a touchpad)
is a pointing device typically built
into the system unit of a notebook
or netbook computer. The device
includes buttons that perform the
same functions as mouse buttons.
In addition, there is a touch-sensitive
pad that can track gestures to move
the on-screen pointer up, down, right,
or left. Many trackpads have an on/off
switch so they can be disabled when
a mouse is used (Figure 2-3).
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FAQ What are the options for specialized PC input
Personal computers are used in so many activities that most computer owners have at
least one specialized input device for playing computer games, taking digital photos, or
scanning printed images. Although the variety of input gadgets seems almost endless, the
most popular devices are discussed below.
A joystick (left) looks like a small version of a car’s
stick shift. Moving the stick provides input to on-screen
objects, such as a pointer or a character in a computer
game. Joysticks (also called game controllers) can include
several sticks and buttons for arcade-like control when
playing computer games. Joysticks can also be adapted
for use by individuals who have difficulty using a keyboard.
A digital camera (left) is a peripheral device used
to capture still images in a digital format that can be
easily transferred to a computer and manipulated using
graphics software. Digital cameras eliminate film and
processing costs. They produce images that can be stored,
manipulated, posted on Web sites, and transmitted as
e-mail attachments.
A digital video camera (left) captures moving images in
a format that can be easily transferred to a computer and
manipulated using photo editing software. Digital video
eliminates the need for costly editing equipment used to
splice film or videotape footage and overlay soundtracks.
Using a low-cost digital video camera and entry-level
video-editing software, computer owners can produce
videos of weddings, vacations, and other significant
events. Webcams are a type of inexpensive digital camera
that remain tethered to a computer and are used for video
conferencing, video chatting, and live Web broadcasts.
A graphics tablet (left) features a pressure-sensitive
surface and pen for free-hand drawing. Pressing hard
with the pen creates a thick, dark line; light pressure
reduces the line width. A digitizing tablet looks similar
to a graphics tablet, but can be much larger in size. It
is typically used by architects and engineers to transfer
points from paper-based drawings into digital format that
can be manipulated by computer aided design software.
A trackball (left) looks like a mechanical mouse turned
upside down. You use your fingers, thumb, or palm to
roll the ball and move the pointer. Onboard buttons work
just like mouse buttons for clicking and double-clicking
on-screen objects. Trackballs perform the same input
functions as a mouse, but require a different set of
muscles for their use. Switching periodically between a
mouse and trackball can prevent some stress injuries.
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A touch-sensitive screen can detect the location of a fingertip or stylus within the
screen area. Touching the location of a screen-based icon, for example, can activate a
menu or similar control. Touch-sensitive screens are used for tablet computers, PDAs,
smartphones, and specialized devices such as information kiosks.
A scanner (Figure 2-5) converts printed images into bitmap graphics that can be
viewed and edited with graphics software. Today, scanning technology is built into most
multifunction printers. A popular use for scanners is to capture old photographs, store
them in digital format, and then use photo editing software to repair cracks, scratches,
and fading. A scanner can also be used to capture pages containing text. When scanned
as a bitmap, the outcome is similar to taking a photograph of the page; the text becomes
part of the page image and cannot be manipulated separately. Some scanners, however,
have optical character recognition ability, which converts the letters and symbols on a
page into digital data that can be edited using word processing software.
A computer uses a standard microphone to collect audio input. The microphone
connector on the system unit is part of the computer’s sound card, which processes
audio input into digital format. Some software applications include built-in speech
recognition, which allows you to dictate commands and data using a microphone,
instead of a keyboard and mouse. Microphones are also handy for annotating e-mail
messages and for narrations designed to accompany Web sites and videos. Audio files
tend to require lots of storage space, however, so you should refrain from recording long
audio segments.
Personal computer peripheral devices also include a variety of sensors, such as water,
smoke, and motion detectors used in PC-based home security systems. Security
devices, such as fingerprint readers, can be connected to a personal computer to prevent
unauthorized access to files and network connections.
Remote controls can also be considered peripheral devices when used to control
computer applications. For example, when using a personal computer as the base for a
home theater system, a remote control can be used to operate the DVD player and adjust
speaker volume.
A variety of input devices have been designed to assist people with physical challenges.
Speech recognition systems are useful when keyboarding is not possible. Adaptive
devices such as specialized keyboards and head pointers offer other alternatives to a
standard keyboard and mouse.
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FAQ What are the most popular display technologies?
A computer display device, sometimes referred to as a monitor, is usually classified as an
output device because it shows the results of processing tasks. Touch-sensitive screens,
however, can be classified as both input and output devices because they accept input
and display output. Two technologies are commonly used for computer display devices:
LCD and LED. These technologies replace heavy, bulky CRT (cathode ray tube) monitors
that used the same technology as old-fashioned televisions.
An LCD (liquid crystal display) produces
on-screen images by manipulating light within
a layer of liquid crystal cells. Modern LCD
technology is compact in size and lightweight,
and provides an easy-to-read display. LCDs are
standard equipment on notebook computers.
Standalone LCDs, referred to as LCD monitors
or flat panel displays, are popular for desktop
computers. The advantages of LCD monitors
include display clarity, low radiation emission,
portability, and energy efficiency.
LED (light emitting diode) technology is used for computer displays in two ways. It is most
commonly used as backlighting for standard LCD panels. Technically, devices with LED
backlighting should be labeled “LED backlit LCD panels,” but many manufacturers advertise
them as LEDs; so when purchasing a display device, check the fine print. LEDs can also be
used in place of LCDs to display the dots of colored light that create a screen image. These
true LED screens have a bright, crisp image, and draw less power than LCDs.
The performance of a display device is a factor of screen size, dot pitch, response time,
color depth, brightness, and resolution. When selecting a display device, it is important to
keep these factors in mind:
• Screen size is the measurement in inches from one corner of the screen diagonally
across to the opposite corner. Screen sizes for standalone displays range from 13" to
28". Notebook screens are typically 15" to 17". Netbook screens are usually 9" to 10".
• Dot pitch (or pixel pitch) is a measure of image clarity. Technically, dot pitch is the
distance in millimeters between like-colored pixels—the small dots of light that form an
image. A dot pitch between .28 mm and .22 mm is typical for today’s display devices; a
smaller dot pitch produces a crisper image.
• Response time is the length of time required for a pixel to change color to keep pace
with the image being displayed on the screen. For example, when playing an action
game, the screen image is constantly changing. A display device with good response
time will maintain a crisp image without the appearance of smearing or ghosting.
Response time is measured in milliseconds, with lower numbers indicating better
response times. Typical response times vary from 6 ms to 2 ms.
• The number of colors a monitor can display is referred to as color depth or bit depth.
Most PC display devices have the capability to display millions of colors. When set at
24-bit color depth (sometimes called True Color), your PC can display more than 16
million colors and produce what are considered photographic-quality images.
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• Wh at are the m ost popular display t e c hnologie s?
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• Screen brightness can be measured as luminance or as a contrast ratio. Luminance is
usually expressed in candela per square meter (cd/m2), with higher numbers indicating
a brighter display. Contrast ratio is the difference between the luminance of white and
black pixels. You can adjust a display’s brightness level; but if you plan to use your
computer outdoors, make sure the screen has a good brightness rating and contrast ratio.
• The number of horizontal and vertical pixels that a device displays on a screen is
referred to as screen resolution. The resolution for many early PC displays was
referred to as VGA (Video Graphics Array). Higher resolutions were later provided by
SVGA (Super VGA), XGA (eXtended Graphics Array), SXGA (Super XGA), and UXGA
(Ultra XGA). These resolutions were supplemented by widescreen versions such as
WUXGA, indicated by prefixing the acronym with “W.” Today’s 1080i and 1080p display
devices typically have 1920 x 1080 resolution, which makes them compatible with
widescreen HDTV standards.
In addition to a display device, your computer’s display system also requires graphics
circuitry that generates signals for displaying images on the screen. One type of graphics
circuitry, referred to as integrated graphics, is built into a computer’s system board.
Graphics circuitry can also be supplied by a small circuit board called a graphics card, like
the one in Figure 2-7.
VGA, HDMI, and DVI ports
Graphics card
A graphics card (also called a graphics board or video card) typically contains a graphics
processing unit and special video memory. A graphics processing unit (GPU) executes
graphics commands, leaving the main processor free for other tasks. Video memory stores
screen images as they are processed but before they are displayed. A fast GPU and lots
of video memory are the keys to lightning-fast screen updating for fast action games, 3D
modeling, and graphics-intensive desktop publishing.
Monitors connect to computers using VGA, DVI, or HDMI ports. You can use these ports to
connect a second monitor to your netbook, notebook, or desktop computer.
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Chapter 2 Peripheral Devices
FAQ What are the most popular printer technologies?
Printers are one of the most popular output devices available for personal computers.
Today’s best-selling printers typically use ink jet or laser technology.
An ink jet printer has a nozzle-like print head that sprays ink onto paper to form
characters and graphics. The print head in a color ink jet printer consists of a series of
nozzles, each with its own ink cartridge. Most ink jet printers use CMYK color, which
requires only cyan (blue), magenta (pink), yellow, and black inks to create a printout that
appears to have thousands of colors. Alternatively, some printers use six ink colors to
print midtone shades that create slightly more realistic photographic images.
Ink jet printers, such as the one in Figure
2-8, outsell all other types of printers
because they are inexpensive and
produce both color and black-and-white
printouts. They work well for most home
and small business applications. Small,
portable ink jet printers meet the needs
of many mobile computer owners. Ink
jet technology also powers many photo
printers, which are optimized to print
high-quality images produced by digital
cameras and scanners.
A laser printer, such as the one in Figure 2-9, uses the same technology as a
photocopier to paint dots of light on a light-sensitive drum. Electrostatically charged ink
is applied to the drum and then transferred to paper. Laser technology is more complex
than ink jet technology, which accounts for the higher price of laser printers.
A basic laser printer produces only black-and-white printouts. Color laser printers are
available, but are somewhat more costly than basic black-and-white models. Laser
printers are often the choice for business printers, particularly for applications that
produce a high volume of printed material.
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• Wh at are the m ost popular print e r t e c hnologie s?
( c ont inue d)
When selecting a printer for your personal computer system, you should consider if its
resolution, speed, duty cycle, and operating costs meet your printing needs.
• Printer resolution. The quality or sharpness of printed images and text depends on
the printer’s resolution—the density of dots that create an image. Printer resolution is
measured by the number of dots per linear inch, abbreviated as dpi. At normal reading
distance, a resolution of about 900 dpi appears solid to the human eye, but a close
examination reveals a dot pattern. If you want magazine-quality printouts, 900 dpi is
sufficient resolution. If you are aiming for resolution similar to expensive coffee-table
books, look for printer resolution of 2,400 dpi or higher.
• Print speed. Printer speeds are measured either by pages per minute (ppm) or
characters per second (cps). Color printouts typically take longer than black-and-white
printouts. Pages that contain mostly text tend to print more rapidly than pages that
contain graphics. Typical speeds for personal computer printers range from 6 to 30 pages
of text per minute. A full-page 8.5" x 11" photo can take about a minute to print.
• Duty cycle. In addition to printer speed, a printer’s duty cycle determines how many
pages a printer is able to churn out. Printer duty cycle is usually measured in pages per
month. For example, a personal laser printer has a duty cycle of about 3,000 pages per
month—that means roughly 100 pages per day. You wouldn’t want to use it to produce
5,000 campaign brochures for next Monday, but you would find it quite suitable for
printing ten copies of a five-page outline for a meeting tomorrow.
• Operating costs. The initial cost of a printer is only one of the expenses associated
with printed output. Ink jet printers require frequent replacements of relatively expensive
print heads. Laser printers require toner cartridge refills or replacements. When shopping
for a printer, you can check online resources to determine how often you can expect to
replace printer supplies and how much they are likely to cost.
• Memory. A computer sends data for a printout to the printer along with a set of
instructions on how to print that data. Printer Command Language (PCL) is the
most widely used language for communication between computers and printers, but
PostScript is an alternative printer language preferred by many publishing professionals.
The data that arrives at a printer along with its printer language instructions require
memory. A large memory capacity is required to print color images and graphics-intensive
documents. Some printers accept additional memory, so you might be able to upgrade if
your printer requires more memory for the types of documents you typically print.
• Duplex printing. Some printers are capable of printing on both sides of the paper, a
feature referred to as duplex printing. The main advantage of duplex printing is cost—
you use half the paper required for single-sided printing. Saving paper is also good for
the environment; so next time you shop for a printer, consider one that offers the option
of duplex printing.
• Networkability. Virtually every business has a computer network, and many
households have them, too. Networks allow multiple computers to share a single printer.
Any standard printer can be accessed over a network as long as it is connected to a
computer on a network that is turned on and allows printer sharing. Some printers,
however, contain circuitry that connects directly to a network rather than to a computer.
Network circuitry adds to the cost of a printer, but is worth considering if you don’t want
to leave one of the computers on your network running all the time.
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FAQ What are the options for specialized output devices?
Personal computer owners tend to collect fewer specialized output devices than input
devices. Nevertheless, specialized output devices are available.
Many computer owners decide to upgrade their computers’ speaker systems to get
better sound quality when listening to digital music and watching digital videos. High-end
computer audio systems include surround sound speakers and a subwoofer to blast
out mellow bass tones. If you live in an environment where a sound system is not
appreciated by your neighbors, you might opt for a set of high-quality earphones, instead.
A plotter is a special type of printer designed to produce line drawings, such as
blueprints. Many plotters are designed to produce large-format printouts—some up to six
feet wide. Plotters are typically purchased for computer systems owned by architects,
engineers, and interior designers.
A voice synthesizer converts digital
text into audio output. Many people are
familiar with the synthesized voice that
narrates weather reports on National
Weather Service radio stations. Voice
synthesizers are also an integral part of
telephone directory assistance and other
automated calling systems.
Voice synthesizers are used as adaptive
devices on personal computers. They
can read the text displayed in a word
processor or on a Web page, making
these computer services available
to people with visual disabilities. For these applications, voice synthesis has a great
advantage over recorded audio files because they are generated on-the-fly and can adapt
to changes that appear on the screen. Windows includes an application called Narrator
(Figure 2-10) that reads the contents of the screen and names screen-based objects as
the mouse pointer encounters them.
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Computer projection devices
are popular with business
people, teachers, and
students who make lots of
presentations. A computer
projection device (Figure
2-11) uses digital light
processing technology to
display a computer-generated
image on a large screen. It is
the ideal device for delivering
PowerPoint presentations to
large groups. As an added
bonus, these projection
devices can be connected
to the DVD player in a home
theater system.
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Chapter 2 Peripheral Devices
FAQ How do I connect peripheral devices to my
When you install a peripheral device, you are basically creating a pathway for data to
flow between the device and the computer. The channel that transmits data between
these devices could be wired or wireless.
Establishing a wired connection between your computer and a peripheral device might
be as simple as connecting a cable, or it could require you to install an expansion card
inside the computer system unit.
Today, USB (Universal Serial Bus) is the preferred way to connect peripheral devices. On
most new computer models, USB ports are conveniently located on the front and sides of
the system unit, so that peripherals can be easily connected and disconnected.
Many kinds of peripheral devices, including mice, scanners, and joysticks, are available
with USB connections. Several types of storage devices, such as USB flash drives and
external hard drives, also use USB connections. Windows automatically recognizes
most USB devices, which makes installation simple. If you want to connect more devices
than the available number of USB ports, you can use USB hubs. A USB hub is an
inexpensive device that turns one USB port into multiple ports. It also saves wear and
tear on USB ports caused by repeatedly inserting and removing USB devices. When
connecting low-power devices—such as a mouse, keyboard, or flash drive—you can use
a bus-powered hub that draws all its power from the computer. For devices such as
printers and external hard disk drives that draw more power, a self-powered hub plugs
into an external power supply (Figure 2-12).
Most personal computers include a variety of USB ports and other built-in ports for
connecting peripheral devices. These ports are pictured in Figure 2-13. When purchasing
a peripheral device, read its specifications to determine what type of port it requires. Make
sure that you use the right cable and insert it correctly into the port.
display port
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network port
USB ports
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Establishing a wireless connection between your computer and a peripheral device typically
requires some type of transceiver on both devices. A transceiver transmits and receives
signals. Those signals could be generated as infrared light, like those used on a television
remote control. Signals could also be generated as radio waves by popular wireless
technologies, such as Bluetooth and Wi-Fi, that you’ll learn about in the Networks chapter.
Wireless peripheral devices typically have a built-in transceiver for a specific wireless
technology. Your computer might have a matching built-in wireless transceiver. If not, you
can usually connect a transceiver to one of your computer’s USB ports.
All PCs have an expansion bus that provides a variety of ways to connect peripheral
devices. An expansion bus is an electronic pathway that moves information between
the microprocessor and RAM, and stretches to various ports and slots where data can be
transferred to other electronic circuitry and devices. In many ways, an expansion bus is
analogous to the transit system within an airport that transports people to different airline
terminals where they can board flights.
Where the expansion bus leads to connection points that can be accessed outside the
system unit, it produces expansion ports, such as USB ports. Connectors inside the
case are called expansion slots. Notebook computers typically have one or two internal
expansion slots dedicated to expanding RAM. In contrast, desktop computers offer
numerous PCI Express (PCIe) expansion slots that can be used for a wide variety of
devices, including the souped-up graphics cards that are so prized by computer game
enthusiasts. Click the Play It! button in Figure 2-14 to learn how to add expansion cards
to a desktop computer.
Expansion slots
In addition to a physical or wireless connection, some peripheral devices also require
software, called a device driver, to establish communication with a computer. Device
drivers are supplied on CDs by the device manufacturer or they can be downloaded from
the manufacturer’s Web site. If needed, directions for installing the device driver are supplied
along with the device. Device drivers work directly with a computer’s operating system and
they work best when designed for the operating system installed in your computer.
Windows 7 includes built-in device drivers for many peripheral devices. This feature,
sometimes called Plug and Play, makes it easy to connect devices without manually
installing device drivers. When you connect a new peripheral device, Windows looks for
an appropriate built-in driver; if one is not found, you’ll be prompted to insert the driver
disc supplied by the peripheral device manufacturer.
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FAQ How do I select components for my computer
Computer technology changes with great frequency. Sorting through computer and
peripheral device choices can challenge even the most savvy shopper. The following
guidelines should help you navigate through computer, software, and peripheral device
Consider the tasks for which you’ll use the computer. Begin by making a list of
activities you expect to do with your computer system. For example, do you want to use
your PC for gaming, word processing, Internet access, graphics, music, or something
entirely different? Will you use your computer system for a combination of tasks, or will it
be dedicated to one particular task, such as small business accounting? Do you want to
use your computer for applications, such as home security monitoring, that might require
specialized hardware or software? Does anyone who will use the computer have special
needs that might require adaptive devices, such as a voice synthesizer or one-handed
keyboard? If you are planning to use specialized peripheral devices or software, check
their system requirements to make sure you purchase a computer that supports them.
Determine your budget. Ask yourself how much money you can afford to spend on
your new computer. Set a price range and shop for the best computer in that range.
As a general rule of thumb, a computer priced higher than US$1,000 is the computer
equivalent of a luxury automobile. A computer in this price range contains a fast
processor, a generous amount of RAM, and copious amounts of disk space. These
computers contain state-of-the-art components and should not have to be replaced as
quickly as less expensive computers.
Computers that retail for between US$500 and US$1,000 might be considered the
four-door sedans of the computer marketplace because a majority of buyers select
computers in this price range. These popular computers lack the flashy specifications of
their state-of-the-art cousins, but provide ample computing power for average users.
In the computer industry, the equivalent of a compact car is a sub-US$500 computer.
Some netbooks and budget PCs cost as little as US$250. Budget computers do
not match the speed, memory size, or disk capacity of more expensive machines.
Nevertheless, budget computers feature many of the same components that owners
coveted in their state-of-the-art computers a few years back. You might, however, have to
replace a budget computer sooner than a more expensive computer.
Select a computer platform. Before you start shopping, you should determine whether
you want a Mac or a PC. To make this decision, consider the platform used by the
majority of your friends and coworkers. If PCs are the standard platform at work, you
should probably purchase a PC for yourself. PCs are the choice of most businesses,
except those focused on artistic endeavors, such as advertising agencies. Many
elementary schools have standardized on the Mac platform, so if you are a teacher or
have children who use Macs at school, that should be your platform of choice.
Choose a desktop, notebook, or tablet configuration. If you want portability, or if
you don’t have much desk space, consider a notebook or tablet computer. Otherwise, a
desktop computer might fulfill your needs. The features of today’s notebook computers
essentially match those of desktop models, but at a somewhat higher price. If you are on
a tight budget and don’t require portability, then go for a desktop model. Another reason
for selecting a desktop model is the amount of expandability it can provide. If you plan to
install lots of peripherals, you want an ergonomically designed keyboard, and you prefer
a large screen display device, you might not be happy with a notebook computer.
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Select processor type and speed. Even after you’ve identified a brand and model,
you might have a choice of microprocessors. Processor speed directly affects computer
performance. A fast processor is essential for some applications such as desktop
publishing, video editing, and serious computer gaming. The fastest processors are
expensive, however, and unnecessary for most routine computing tasks.
Select an operating system. Macintosh computers are shipped with the current version
of Mac OS, but you can add Windows to an Intel Mac computer using software such
as Boot Camp or Parallels. PCs can be shipped with Windows or Linux, but that choice
is typically easy to make. Linux would be the operating system of choice if you plan to
operate a network or Web server. For the typical personal computer system, Linux limits
your choice of software applications and might not provide device drivers for some of the
peripheral devices you want to install. PC buyers typically choose the Windows operating
system because of its flexibility and because it is the PC standard.
When you purchase a PC, you might have a choice of Windows versions. Microsoft
typically offers Windows in Home versions and Professional versions. The Professional
versions provide some enhanced security and networking options not available on Home
versions. Unless you plan to operate a small business network, Home versions should be
sufficient for your needs.
Regardless of the operating system you select, make sure it is the most recent version.
Older operating systems might not support the newest software applications or some new
peripheral devices.
Consider your storage needs. A hard disk serves as the main storage device for your
computer. Most of today’s computers offer at least 250 GB of hard disk space. That
amount should be sufficient for most personal computer owners. Music, video, and
graphics files are large; so if you plan to store many of these files, you might want to
upgrade to a larger hard disk.
Your computer should include an optical drive for making backups and installing software
from distribution disks. Netbooks, however, typically don’t have enough room in the
system unit for an optical drive, so you might want to purchase an external optical drive
that connects to your netbook with a USB cable.
Consider RAM and video memory capacity. Today’s computers include at least 2
GB of RAM. Lots of RAM capacity is better for memory-intensive applications such as
desktop publishing and video editing. Additional RAM raises the price of a computer.
If you are on a tight budget, remember that you can add RAM later if your applications
demand it.
If you intend to use your computer for 3D action games, video editing, or desktop
publishing, you’ll want high-performance graphics components. On some computers,
the graphics card circuitry is built into the motherboard and a section of RAM handles
graphics-related tasks. This technology, usually referred to as shared memory (or
integrated graphics), does not match the performance of a dedicated graphics card and
video memory. Look for dedicated graphics and at least 1 GB of video memory if you
plan to tackle serious graphics applications.
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Chapter 2 Peripheral Devices
• How d o I s e le c t c om pone nt s f or m y c om put e r syst em ?
( c ont inue d)
Evaluate the computer’s upgradeability. Some computers are easier than others to
expand and upgrade. As a rule of thumb, desktop models are easier to upgrade than
notebooks, which often contain specialized components designed to fit in a small system
unit. If you want expandability, look for open drive bays that can hold additional hard
disk, CD, and DVD drives. Ask about the number of expansion slots provided for network,
video, and audio expansion cards. Also, look at the position and number of ports for
connecting peripheral devices. Multiple USB ports are handy—especially if they are easily
Select software. Most computers are shipped with the operating system preinstalled.
Remember that Windows includes several utilities and applications, such as rudimentary
graphics, compression, backup, defragmentation, Web browsing, and e-mail software.
Many computer vendors also install a “bundle” of application software packages. A
typical software bundle includes word processing, spreadsheet, presentation, and
antivirus software. This software is handy for just about everyone, and computer buyers
can typically save money by purchasing a bundle along with a new PC. Some of the
software bundled with a PC is typically trial software that you can use without charge for
a short period of time, but have to pay to use after the trial period ends. Make sure you
understand if an application is trialware. If you don’t pay when the trial period ends, you
could lose access to data files that you created when using it.
Select peripheral devices and accessories. Always find out what is included in the
price of a computer system, and carefully consider whether each device will be useful
for your computing projects. Low-cost desktop computers might not include display
devices. After factoring in the price of a display device, these systems might not be such
a good deal. In contrast, some vendors offer special hardware bundles that include an
LCD display, printer, PDA, and digital camera. When purchasing a notebook computer,
you should consider buying an extra battery, carrying case, A/C adapter for using an
electrical wall outlet, and D/C adapter for in-car use. Because many of these accessories
are designed specifically for a particular notebook model, they might not be available in a
year or two.
Evaluate manufacturer and vendor support and warranty. When you encounter
hardware and software problems, you want them fixed as quickly as possible. Technical
support and repair service is usually available from the company that manufactured
the equipment or published the software. Support and service might also be available
from the merchant or vendor. Before you make a final decision on computer equipment
or software, ask the following questions: Does the price of the equipment or software
include technical support? How long does the support last? How can you contact
technical support? Is it free? Is the support staff knowledgeable? What is the duration
of the equipment warranty? Does it cover the cost of parts and labor? Where do repairs
take place and is there a shipping cost? How long do repairs typically take?
Shopping for computer equipment and software can be a challenge; but if you take a
careful, organized approach, you can usually buy with confidence. Remember to use all
available resources, such as vendor Web sites, magazine reviews, and recommendations
from friends and experts.
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Chapter 2 Peripheral Devices
QuickCheck A
1. A(n)
converts printed images into bitmap graphics that can be viewed
and edited with graphics software.
2. A(n)
screen is standard equipment on most notebook computers and is
the technology used for most of today’s standalone display devices.
3. A graphics card typically contains special video
, which stores screen
images as they are processed, but before they are displayed.
4. True or false? Today, USB (Universal Serial Bus) is the preferred way to connect
peripheral devices.
5. True or false? As a general rule of thumb, a computer priced higher than US$750 is the
computer equivalent of a luxury automobile.
QuickCheck B
Enter Y for the ports that are
shown in the photo, enter N if the
port is not shown in the photo.
1. USB port
2. Display port
3. Network port
4. Audio port
5. FireWire port
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