<hardware> A hardware device consisting of a number of
mechanical buttons (keys) which the user presses to input
characters to a computer.
Keyboards were originally part of terminals which were
separate peripheral devices that performed both input and
output and communicated with the computer via a serial line.
Today a keyboard is more likely to be connected more directly
to the processor, allowing the processor to scan it and detect
which key or keys are currently pressed. Pressing a key sends
a low-level key code to the keyboard input driver routine
which translates this to one or more characters or special
actions.
Keyboards vary in the keys they have, most have keys to
generate the ASCII character set as well as various
function keys and special purpose keys, e.g. reset or volume
control.
