(^454) PC Hardware: A Beginner’s Guide
Keyboard Layouts and Styles
Keyboards, regardless of which region of the world they are from, tend to follow some
fairly basic layout patterns. The style and layout of a keyboard is a direct function of the
number of keys it has. It is logical that a keyboard with only 83 keys can be much smaller
and more simply laid out than one with 108 keys.Early Keyboards
The very first PC keyboards were those of the IBM PC and PC XT. These keyboards had
83keys.Judgedbytoday’skeyboards,thiskeyboarddesigndoeshaveitsfaults,butitdid
establish the design basis for all keyboards that followed. Some of its more enduring
characteristics were that it was a separate unit from the PC, had ten function keys, and
included a ten-key number/cursor control pad.
The84-keykeyboardoftheIBMPCATaddedoneadditionalkey,theSYSTEMREQUEST
key, and made several other adjustments, including better spacing of the keys, enlarging
theSHIFTandENTERkeys, and adding three LED indicators to the keyboard for the locking
keys (CAPS LOCK,NUM LOCK, andSCROLL LOCK).Enhanced Keyboards
The last version of the IBM PC AT (Model 339), which was introduced in 1986, included an
enhanced keyboard (as IBM called it) that had 101 keys. This keyboard, with some minor
variations and not too many added keys, continues to endure as the de facto standard for
all keyboards. Actually, there isn’t much you can do to revolutionize keyboards beyond
adding special keys and functions. Over the years, keyboards have remained true to the
basic design of the Enhanced 101 keyboard. Even the newest emerging keyboard standard,
the 104-key Windows keyboard (see below) is virtually identical to the 101-key design.
The primary differences between the enhanced keyboard and the 84-key AT key-
boardaretheadditionofthededicatedcursorcontrolkeys,newmultiplyanddividekeys
on the number pad,CTRLandALTkeys on the right side of theSPACEBAR, and two more
function keys.
Variations of the enhanced keyboard exist for non-English speaking regions of the
world. Most of these variations have 102 keys to incorporate additional special characters
and language-specific symbols. The differences are primarily in the keys, with many
special characters moved or replaced (different money symbols are common), but some
arrangement differences also exist. For example, the top row of keys on an English-language
keyboard starts with QWERTY keys. In France and other countries, these keys are
AZERTY because of the frequency that these letters occur in other languages.