Computer Interfacing

6 The computer keyboard

and VDU

There is a variety of devices which allow a user to input

data directly into the computer. Of these the keyboard

is certainly the most familiar and commonly used. Other

devices, such as the mouse, trackerball, graphics tablet

and so on, act merely as sometime alternatives to the

keyboard and not as complete replacements.

The complexity of a keyboard may vary between the

spartan simplicity of a hexadecimal keypad (providing

nothing more than the hexadecimal digits 0-9, A-F, plus

a few control functions) and the luxury of a full

typewriter-style keyboard. The latter may well have been

expanded even further by th ...