This document lists and describes various computer input and output devices. It discusses keyboards, mice, trackballs, joysticks, light pens, scanners, webcams, MICR, OMR, bar code readers and speech input devices. It also covers monitors, printers, plotters, projectors and speakers as common output devices. The document provides brief explanations of how each device functions and examples of their typical uses.

2. Input Devices
Keyboard
Mouse
Trackball
Joystick
Light Pen
Scanners
Web Cam
Magnetic Ink Character Recognition(MICR)
Optical Mark Recognition (OMR)
Bar Code Reader
Speech Input Devices
Touch Screen

3. Input Devices
a) Keyboard is a input device which we used most to input the
data. The data and instructions are input by typing.
b) Earlier, cable connected keyboards were there but now
wireless keyboards are also available.
a) Mouse a pointing device.Mouse controls
the movement of the cursor in the screen.
a) Earlier, as cable connected keyboard were
there similarly mouse were also there but
now wireless mouse are also available.

4. a) Scanners are used to enter information directly in to
the computers memory. This device works like a Xerox
machine. The scanner converts any type of printed or
written information including photographs into digital
form, which can be change by the computer.
Track ball is similar to the mouse.
The user moves the ball directly,
while the device itself remains stationary.
The user spins the ball in various directions
to effect the screen movements.

5. a) A light pen is a input device in the form of light
sensitive. It allows the user to point to displayed
objects, or draw on the screen, in a similar way to a
touch screen but with better accuracy.
b) A light pen can work with any CRT-based monitor,
but not with LCD screens, projectors or other
display devices.
c) Now these are converted
into stylus which are used
with touch screen.

6. A webcam is a video camera which feeds its images in real time to a computer.
7) Speech Input Devices:
It convert a person’s speech into digital
form.
8) Bar Code Reader:
It is a photoelectric scanners that read the bar codes,
or vertical zebra striped marks, printed on product containers.
Used in supermarkets, bookshops etc.
9) Optical Mark Recognition:
It is also called mark sensing is a technology where an OMR device senses the presence
or absence of a mark, such as a pencil mark. OMR is used in tests such as aptitude tests.
10) MICR:
It allows the computer to recognize characters printed using magnetic ink. Used in
banks.
11) Joystick:
A lever that moves in all directions and controls the movement of a pointer or some other
display symbols.

7. List of Output Devices
(with their price and latest model)
a) A monitor is a output device which display graphics to
users.
b) Monitors are of various type like CRT, LCD, LED.
c) Monitors which are coming today are touch screen
which can be used as output as well as input device.

8. a) A printer is an output device that prints text, images.
b) Printer help users to get data from computer from
electronic form to paper form.

9. a) The plotter is a computer printer for printing vector
graphics.
b) It is use for printing big posters whereas printer are
used for printing data on pages.

10. a) A device that is used to project rays of light, with a
system of lenses for projecting slides or film on a screen.
b) These are used for basically presenting computer data
on a large screen.

11. a) Speakers are that output devices which plays the sound
or music.
b) Speakers are used for listening media data.