Chapter 2
Peripheral Devices
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What’s inside and on the CD?
• This chapter provides an overview on:
– Keyboard and mouse
– Specialized input devices
• Trackpads
• Digital cameras
• Joysticks
– Display devices and printers
– Voice synthesizers and plotters
– Technologies that provide easiest connections
– Component purchasing
– Tips to help when shopping for a computer, software,
and peripheral devices
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What is a peripheral device?
• A peripheral device is any input or output component
that connects to a computer
• Standard components include:
– Keyboard
– Mouse
– Display unit
– Printer
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What is a peripheral device?
• Specialized peripheral devices include:
– Playing games
– Monitoring home security
– Capturing video images
• Specialized peripheral devices are key components of
large-scale computers
– High-speed printers for mass mailings
– High-speed optical character readers in banks
– Computer-controlled robots for:
• Arc welding
• Circuit board assembly
• Painting
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What is a peripheral device?
– Handheld scanning devices keep track of package
deliveries
– UPC scanners in check-out lanes
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What are the options for standard
input devices?
• The keyboard is the most important input device on
desktop and notebook computers
– Design of keyboard is based on typewriter’s
QWERTY layout
– Additional keypad for editing
– Function keys for computer-specific tasks
– Numeric keypad
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What are the options for standard
input devices?
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What are the options for standard
input devices?
• Pointing devices manipulate on-screen pointer
– Mice
– Trackballs
– Pointing sticks
– Trackpads
– Joysticks
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What are the options for standard
input devices?
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What are the options for specialized
PC input devices?
• A joystick looks like car’s stick shift
– Controls objects on screen
– Can be adapted for physical challenges
that make it difficult to use keyboard
• A digital camera used to capture still images
– Easily transferred to computer
– Produce images that can be stored,
manipulated, posted on the Web, and
transmitted as email attachments
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What are the options for specialized
PC input devices?
• A digital video camera captures moving
images
– Easily transferred to computer
– Easily edited on computer
• A graphics tablet features pressure-sensitive
surface and pen for free-hand drawing
• A digitizing tablet provides flat surface for
vector drawing such as blueprints and technical
drawings
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What are the options for specialized
PC input devices?
• A touch-sensitive screen can detect the location
of a fingertip or stylus within the screen area
• A scanner converts images into bitmap graphics
that can be viewed and edited with graphic
software
– Can capture old photographs
– Scanned Text can be manipulated if scanner
has optical character recognition
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What are the options for specialized
PC input devices?
• Standard microphone is used to collect audio input and is
part of sound card
– Some software has speech recognition to allow for
voice commands instead of keyboard and mouse
– Handy for narrations on Web sites and videos
– Require lots of storage space
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What are the most popular display
technologies?
• LCD display produces image by manipulating light within
layer of liquid crystal cells
• CRT display device, such as glass tube on standard TV
• Plasma screen creates image by illuminating miniature
colored fluorescent lights in panel-like screen
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What are the most popular display
technologies?
• Performance of display device is factor of:
– Screen size
– Dot pitch
– Response time
– Color depth
– Contrast ratio
– Screen resolution
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What are the most popular printer
technologies?
• Today’s printers typically use ink jet or laser technology
– An ink jet printer has nozzle-like print head that
sprays ink to form characters and graphics
• Inexpensive choice of most home and small
business applications
• Print high quality images produced by digital
cameras and scanners
– A laser printer uses same technology as photocopier
• More expensive
• Choice for business printers that produce high
volumes
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What are the most popular printer
technologies?
• When selecting printer consider:
– Print resolution
– Print speed
– Duty cycle
– Operating costs
– Memory
– Duplex printing
– Networkability
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What are the options for specialized
output devices?
• Upgrade computer’s speaker system for better sound
quality
• A plotter is a special printer for line drawing such as
blueprints
• A voice synthesizer converts digital text into audio
output
• A computer projection device displays computergenerated images on large screen
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How do I connect peripheral devices
to my computer?
• Installation is a pathway to transmit data between device
and computer
– Wired connection may require only connecting wire to
computer or may require adding expansion card to
system unit
– Most computers include a variety of built-in ports for
connecting devices
– Today, USB (universal serial bus) is the preferred way
to connect devices
– Wireless connection typically requires transceiver on
both devices
• Infrared light
• Bluetooth
• Wi-Fi
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How do I connect peripheral devices
to my computer?
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How do I connect peripheral devices to my
computer?
• If peripheral device requires a port not on your computer,
you install an expansion card
• Some devices require software, called device driver, to
set up communications
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How do I select components for my
computer system?
• Guidelines for purchasing peripheral devices:
– Consider the tasks for which you’ll use the computer
– Determine your budget
– Select a computer platform
– Choose a desktop, notebook, or tablet configuration
– Select processor type and speed
– Select an operating system
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How do I select components for my
computer system?
–
–
–
–
–
–
Consider your storage needs
Consider RAM and video memory capacity
Evaluate the computer’s upgradeability
Select software
Select peripheral devices and accessories
Evaluate manufacturer and vendor support and
warranty
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