Hardware Reference
In-Depth Information
Several keyboards on the market have special features not found in standard designs. These
additional features range from simple things, such as built-in calculators, clocks, and volume control,
to more complicated features, such as integrated pointing devices, special character layouts, power
management keys, special shapes, internal lighting, and even user-customizable or programmable
keys.
Note
In 1936, August Dvorak patented a simplified character layout called the Dvorak Simplified
Keyboard (DSK). The Dvorak keyboard was designed to replace the common QWERTY
layout used on nearly all keyboards available today. The Dvorak keyboard was approved as an
ANSI standard in 1982 but has seen limited use.
Ergonomic Keyboards
A trend began in the late 1990s to change the shape of the keyboard instead of altering the character
layout. This trend has resulted in several so-called
ergonomic
designs. The goal is to shape the
keyboard to better fit the human hand. The most common of these designs splits the keyboard in the
center, bending the sides outward. Some designs allow the angle between the sides to be adjusted,
while others are fixed. The split or bent designs more easily conform to the hands' natural angles
while typing than the standard keyboard allows. They can improve productivity and typing speed and
help prevent repetitive strain injuries (RSI), such as carpal tunnel syndrome (tendon inflammation). A
good source for highly ergonomic keyboards, pointing devices, and furniture is Ergonomic Resources
Keyboard Troubleshooting and Repair
Keyboard errors are usually caused by two simple problems. Other more difficult, intermittent
problems can arise, but they are much less common. The most frequent problems are as follows:
• Defective cables
• Stuck keys
Many older keyboards, such as the heavy-duty units made by IBM, had replaceable cables. Defective
cables are easy to spot if the failure is not intermittent. If the keyboard stops working altogether or
every keystroke results in an error or incorrect character, the cable is likely the culprit. Trouble-
shooting is simple if your keyboard has a detachable cable, especially if you have a spare cable on
hand. Simply replace the suspected cable with one from a known, working keyboard to verify
whether the problem still exists. If it does, the problem must be elsewhere.
Most modern keyboards have nonreplaceable cables, at least from the outside. In some cases you can
open the keyboard case, and you will see that the cable is internally connected via a removable plug.
Unfortunately, those cables are not sold separately, meaning that the only source for one would be
from another keyboard, making a replacement implausible.
If the cable is removable, you can test it for continuity with a digital multimeter (DMM). DMMs that
have an audible continuity tester built in make this procedure much easier to perform. To test each
wire of the cable, insert the DMM's red pin into the keyboard connector and touch the DMM's black
pin to the corresponding wire that attaches to the keyboard's circuit board. Wiggle the ends of the
cable as you check each wire to ensure no intermittent connections exist. If you discover a problem
