*input devices *basics of computer

1. Input devices
Presented by:
varsha

2. Input Unit
● The devices which are used to input the data and programs in the
computer are known as "Input Devices". Input unit accepts instructions
and data from the user and converts these instructions and data in
computer acceptable format which are sent to computer system for
processing.
● A piece of equipment/hardware which helps us enter data into a
computer is called an input device. For example keyboard, mouse, etc.

3. Keyboard:
Keyboard is most common input device. The data and
instructions are input by typing on the keyboard. The
message typed on
the keyboard reaches the memory unit of a computer. It
is connected to
a computer via a cable. Apart from alphabet and
numeral keys, it has
other function keys for performing different functions.

4. Mouse
It is a pointing device. The mouse is rolled
over the mouse pad,which in turn controls
the movement of the cursor in the screen.
You can click, double click or drag the
mouse. Its sensor notifies the speed of its
movements to the computer, which in turn
moves the cursor/pointer on the screen.

5. Scanner
Scanners are used to enter information directly in
to the computer memory. This device works like a
Xerox machine.
The scanner converts any type of printed or written
information including photographs into digital
pulses, which can be manipulated by the computer.

6. Voice Input System(MIC)
It converts spoken words to machine
language form. A microphone is used to
convert human speech into electric
signals.
The signal pattern is then transmitted to a
computer when it is compared to a
dictionary of patterns that have been
previously placed in a storage unit of
computer. When a close match is found,
the word is recognized.

7. Light pen:
This is an input device which is used to
draw lines or figures on a computer screen.
It is touched to the CRT screen where it can
detect raster on the screen as it passes.