Computers:
Information Technology in Perspective, 11e
Larry Long and Nancy Long
Chapter 6
Information Input and Output
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Objectives

Once you have read and studied this chapter,
you will have learned:
 The
operation and application of common input
devices.
 The operation and application of common output
devices.
 The scope of and technology for multimedia
applications.
 The breadth of assistive input/output technology for
disabled people.
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Why this chapter is important to you!



Understanding what input/output devices are
available will enable you to take full advantage
of your computer
Learning about input/output devices can help
you make informed decisions related to
ergonomic purchases
Using certain input/output devices can help you
to be more productive at work and in your
personal life
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Input Devices



Input devices translate
our data and
communications into a
form that the computer
can understand
The computer processes
the data
Output devices translate
the data back into a form
we can understand
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The Keyboard

Two types of keyboards:

Alphanumeric





Typical keyboard has 101
keys
12 function keys
Special-function keys
Cursor-control key
Special-function

Designed for specific
application

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Example: cash register
5
Point-and-Draw Devices



GUI lets you point and
click
With a mouse you can
draw, drag and drop,
click, and double-click
A mouse can have one or
two buttons, and some
have a wheel for scrolling
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Additional Point-and-Draw Devices
Joystick
Trackball
Digitizer Tablet
and Pen
Trackpad
Trackpoint
Photos Courtesy of:
• Imation Corporation
•Houston Instrument Div. AMETEK, Inc.
•Advanced Gravis Computer Technology Ltd.
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Scanners


Scanners read and
interpret information
on printed matter
The information is
converted to a format
for storage
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OCR and Bar Code Scanners

Optical character
recognition (OCR)
 Reads
coded
information and text
 Types

Contact and Laser



Handheld
Label
Document
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Optical Mark Recognition


Grades test
Checks survey
 The
sense marks are
compared on the test
by the scanner
 Corrections are
calculated
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Optical Scanners


Digitizes an image
Image processing


Manipulates and manages
the scanned image
Two types:

Page image scanners


Works like a copy
machine
Hand image scanners

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Rolled over the image
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Image Processing

Eliminating the paper pile
 Once scanned in
documents can be easily
retrieved
 Once scanned in
documents and images
can be manipulated
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Magnetic Stripes and Smart
Cards



Magnetic stripes on the
back of bank cards and
ID badges are encoded
with data
When they are swiped
the device reads the card
Smart cards look like a
regular bank card, but
contain 32 KB of memory
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Speech Recognition



Today’s speech-recognition
software will record a person
speaking up to 125 words a
minute
Considered the newest “killer
application”
Includes:




Speaker-dependent system


Software
Generic vocabulary database
High-quality microphone
Need to train systems
Speaker-independent
systems

Limited capabilities
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Pattern Recognition




Uses a camera to digitize
the image
Stores digitized image in
a database
Continually compares
new images to stored
images in database
Suited to very specialized
tasks like quality-control
inspections
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Digital Cameras

Captures still and video
imagery



Good digital camera costs
as little as $200
Memory cards or memory
sticks can be uploaded to a
PC
Photos can then be
inserted in a document, emailed to family or more
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Desktop Video Cameras


Captures motion
video in the area of
the PC
Two purposes
 Videophone
 Webcams
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Digital Camcorders


Video is stored on a
digital tape that can
be uploaded to a PC
Costs are from $500
to $1000
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Handheld and Wearable Data Entry Devices

Actually a small computer
which includes:





Limited external keyboard
or soft keyboard
Small display (touch
sensitive)
Storage capacity (flash
memory)
Scanning device for OCR
Capture data and upload
to a central computer
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Touch Screen Monitors


Touch screen
monitors have
pressure-sensitive
overlays that detects
pressure
Users touch the icon
or menu item to make
their selections
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Output Devices




Monitors
Printers
Sound systems
Voice-response
systems
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Monitors

CRT monitors
 Excellent
resolution
 Larger size

Flat-panel monitor
 Found
on all
notebooks
 More expensive
 Takes up less space
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Graphics Adapters
Device controller for the monitor
Inserted into expansion slot
Most graphics adapters have their own
video RAM (VRAM)
Size of video RAM is important
VRAM determines the number of possible
colors and the resolution of the display
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Monitor Size





15 inch
17 inch
19 inch
21 inch
The bigger the more
costs
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Monitor Resolution
1024 pixels
768
pixels
Students are great!
The size of the screen image
is measured in pixels.
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Monitor Resolution – Bits Used
Grayscale
 RGB monitors
 Color depth

 8-bit
(246 colors)
 16-bit (high color, 65,536
colors)
 24-bit or 32-bit (true color,
>16 million colors)
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Monitor Resolution-Dot Pitch
The distance between centers of adjacent pixels.
Low Resolution
Higher Resolution
.28mm (millimeters) or less is recommended
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Refresh Rate


The number of times
per second the
screen image is
redrawn
Faster refresh rates
have fewer flickers
and is easier on the
eyes
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LCD Projectors


Presentation graphics
Multimedia projectors
 LCD
panels
 LCD projectors
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Wearable Displays


Wireless headset
RSD



Screen outside the eye
Addresses the retina with a
stream of pixels
Uses


For privacy
Gather information while
still working
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Printers


Printers produce hardcopy such as term
papers, reports, labels,
and more…
Considerations:






Budget
Black/white or color
Volume
Quality
Special needs
Network considerations
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Page Printers





Nonimpact
Laser, LED, LCS
High speed 4-32 ppm
Near-typeset-quality
600 dpi to 1200 dpi
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Ink-Jet Printers




Nonimpact
Budget-minded
consumer’s choice
1200 dpi for
black/white
4800 dpi for color
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Other Printers

Dot-matrix
 Prints
one character at
a time

All-in-one
 Print
 Fax
 Scan
 Copy
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Sound Systems

Today’s PCs
 Play
DVD movies
 Record and play CDs
and MP3 music
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Voice Response Systems

Two Types:
 Reproduction
of
human voice and
sounds
 Speech synthesis
(text-to-speech
software)
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Multimedia

Multimedia experience:








The Internet
Video editing
Presentations
Kiosks
Tutorials
Online references
Family photo album
Entertainment center

Multimedia growth:






Video cameras
Synthesizer
Video capture card
Scanner
CD-RW/DVD-RW
Multimedia files




Text files
Sound files
Image files
Animation files
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Technology for the Disabled
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Summary




Input devices
Output devices
The multimedia
experience
Technology for the
disabled
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