Input devices capture information from the external environment and translate it into a format readable by computers. Common input devices include keyboards, pointing devices like mice and trackballs, game controllers, scanners, styluses, microphones, and digital cameras. Output devices take the information processed by computers and present it to users in a form they can understand, like monitors to display visual information and speakers to output audio.

3. • Input device captures information and translates it into a form
that can be processed and used by other parts of your computer.
Keyboards
Pointing devices
Game controllers
Scanners
Styluses
Microphones
Digital cameras
Web cams

5. The keyboard is the most common input
device. Types of keyboards include:
• Wireless
• Multimedia and one-touch access
• Portable keyboards for PDAs

7. Pointing devices are mainly used to choose and enter
commands
Pointing devices tend to have PS/2 connectors or
USB connectors
• PS/2 connector fits into a PS/2 port, which a small round
socket with small holes that fit the pins on the connector
• USB connectors fit into USB ports, and these are small
rectangular openings on the back or front of your computer,
or even on your keyboard or monitor

8.  Various pointing devices are available
 Types of pointing devices:
• Mouse
Mechanical mouse
Optical mouse
Wireless mouse
• Trackball
• Touchpad
• Pointing stick

9. Game controllers are used mainly to play games
Types of gaming devices
• Gamepads
• Joysticks
• Gaming wheels
• Force feed

10. Other types of input devices include:
• Scanners
• Styluses
• Microphones
• Digital cameras
• Web cams

11. •Scanner is a light sensitive device that helps you
copy or capture images, photos, and artwork
that exist on paper. Types of scanners include:
Flatbed

12. • Stylus is an input device consisting of a thin
stick that uses pressure to enter information
or to click and point
• Styluses are used with:
PDAs
Tablet PCs
Graphics tablets

13. • Microphones are used to input
audio
• Three main types of
microphones are:
Desktop microphones
Headsets
Directional microphones
• Speech recognition is
increasingly being included in
application software

15. Output devices take information
within your computer and present
it to you in a form that you can
understand
Main output devices:
Monitors
Printers
Speakers

17. Devices with flat-panel displays
• Tablet PCs
• PDAs
• Cellular phones
• Desktop computers

18. CRTs
Flat-panel displays
Gas plasma
LCD (liquid crystal display)
Passive matrix
Active matrix
Called TFT (thin film transistor)
Separate transistor for every pixel

19. Screen size measured as a diagonal line across the
screen – from corner to opposite corner
Resolution the number of pixels displayed on the
screen (the higher the resolution, the closer together
the dots)
Pixels (or picture element) dots that make up the
image on your screen
Dot pitch is the distance between the centers of a
pair of like-colored pixels
Refresh rate the speed with which a monitor redraws
the image of the screen, and is measured in hertz

20. Inkjet – most popular
Makes images by forcing droplets through
nozzles
Top speed is 20 pages per minute
Laser
Forms images using an electrostatic
process
Prints between 3 and 30 pages per minute

21. Resolution of a printer is the number of
dots per inch (dpi) it produces.
Higher the resolution, better the image,
and usually the more costly the printer

22. Multifunction printer:
• Scan, copy, fax, and print
• Can be either inkjet or laser
• Cost less than buying individual
units
• Take up less desk space

23. A speaker is a device that
produces computer output as
sound
Speakers are common devices
in computer systems
Examples include:
• Built-in speaker
• Two-device set speakers
• Surround sound speakers