1. Chapter 5 – Part 2 Input and Output
Computers: Tools for An Information Age

2. Output: Information for the User
Computer screens
Printers
Voice output
Music output
Microform

3. Computer Screen Technology
Screen is part of computer’s monitor
Screen output known as soft copy
temporary
Common forms
Cathode ray tube (CRT)
Flat-panel screens

4. CRT Screens Display text and graphics Most are in color
Graphics card converts signals from the control unit into the image the user sees

5. Factors Affecting Performance
Scan rate
The frequency with which the image is refreshed
Resolution (clarity) of screen
Measured in pixels (picture elements)
The more pixels, the higher the resolution
Dot pitch
The amount of space between dots
The smaller the dot pitch, the sharper the image
Video memory
A high-speed form of RAM installed on graphics card

6. Graphic Standards
Agree on resolutions, colors, other issues related to displaying graphics
Super Video Graphics Adapter (SVGA) is most common standard
Provides 800 (horizontal) x 600 (vertical) pixels on the display
Support 16 million colors
The number of colors that can be displayed depends on amount of video memory

7. Flat-Panel Screens Liquid crystal display (LCD)
Very thin (only a few inches)
Produce sharper text images than CRTs
Easier on eyes than CRTs
Flat-panel technologies

8. LCD Technologies Active-matrix Passive-matrix Gas plasma
Uses many thin-film transistors (TFT)
Produces brighter image and can be viewed from wider angles
Passive-matrix
Uses fewer transistors
Cheaper and uses less power
Gas plasma
Supports very large displays
Has brilliant color display
Viewable at very wide angles

9. Printers Produce information on paper output Orientation settings
Printed output known as hard copy
Orientation settings
Portrait - vertical alignment
Landscape - horizontal alignment
Two ways of printing
Impact printer
Nonimpact printer

10. Impact Printers Physical contact with paper required to produce image
Dot-matrix printer
Has print head consisting of one or more columns of pins
Pins form characters and images as pattern of dots

11. Nonimpact Printers
Places an image on a page without physically touching it
Laser printer
Uses light beam to help transfer images to paper
Produces high-quality output at very fast speeds
Ink-jet printer
Sprays dots of ink
Less expensive than laser printers

12. Voice Output Converts data to vocalized sounds
Used in automated telephone-based customer service applications

13. Music Output Multimedia clips, games, videos include sight and sound
Speakers placed on side of monitor

14. Computer Output Microform (COM)
Output of photographically reduced images on microfilm
Common use
Libraries store back issues of magazines, newspapers, etc.

15. Terminals Combine input and output capabilities Dumb terminal
Keyboard for input and monitor for output
No processing capability
Intelligent terminal
Has limited memory and a processor

16. Computer Graphics Business graphics Video graphics
Computer-aided design (CAD)

17. Business Graphics A powerful way to display information
Colorful graphics, maps, and charts help managers compare data, and make quicker decisions
As underlying data changes, charts and graphs are instantly updated

18. Terminals Combine input and output capabilities Dumb terminal
Keyboard for input and monitor for output
No processing capability
Intelligent terminal
Has limited memory and a processor

19. Video Graphics A series of video images Used extensively in television
Displayed rapidly to give the impression of motion
Used extensively in television
Also used in computer and arcade video games

20. Computer-Aided Design (CAD)
Creates two- and three-dimensional (2D and 3D designs)
Serves as bridge between design and manufacturing