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A Keyboard is a primary input device that is used mainly for
inputting text. Its key-arrangement was patterned from and electronic
and mechanical typewriter.
The standard layout of letters, numbers, and punctuation is known
as a QWERTY keyboard because the first six keys on the top row of
letters spell QWERTY. The QWERTY keyboard was designed in the 1800s
for mechanical typewriters and was actually designed to slow typists
down to avoid jamming the keys. Another keyboard design, which has
letters positioned for speed typing, is the Dvorak keyboard.
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| There is no standard
computer keyboard, although many manufacturers imitate the keyboards
of PCs. There are actually three different PC keyboards: the original
PC keyboard, with 84 keys; the AT keyboard, also with 84 keys; and
the enhanced keyboard, with 101 keys. The three differ somewhat
in the placement of function keys, the Control key, the Return key,
and the Shift keys.
In addition to these keys, IBM keyboards contain the following
keys: Page Up, Page Down, Home, End, Insert, Pause, Num Lock, Scroll
Lock, Break, Caps Lock, Print Screen.
There are several different types of keyboards for the Apple Macintosh.
All of them are called ADB keyboards because they connect to the
Apple Desktop bus (ADB). The two main varieties of Macintosh keyboards
are the standard keyboard and the extended keyboard, which has 15
additional special-function keys.
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