INPUT DEVICES....!!! The input unit is formed by the input devices attached to the computer. Ex - Keyboard, Microphone etc. An input unit takes the input & converts it into binary form so that it can be understood by the computer.

KEYBOARD : This is most commonly used device which acts as input device. Its structure is like typewriter.It contains no. of keys which have some specific ASCII values. Like ‘A’ has ASCII value 65. When this is pressed , it is converted into 65 & this 65 is sent to CPU in the form of Binary language (i.e. 1000001). Then operations are done on this data. MOUSE : This is a pointing device which contains a roller in its base. When the mouse is moved on any surface, the pointer on the screen is also moved. It contains a potentiometer coupled with the roller. This potentiometer senses the motion of mouse & convert it into digital value. A mouse may contain two or three buttons. Now a day's optical mouse are very popular.