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Table 9.8 Keyboard Connector Signals Continued
Signal Name 5-Pin DIN 1 6-Pin Mini-DIN 6-Pin SDL 2
Not Connected — 6 F
Not Connected 3 — —
1. DIN = German Industrial Norm (Deutsche Industrie Norm), a committee that sets German
dimensional standards.
2. SDL = Shielded Data Link, a type of shielded connector created by AMP and used by IBM and
others for keyboard cables. It is used inside the keyboard housing to attach the cable to the keyboard’s
electronics, and the other end of the cable will have the DIN or mini-DIN connector to
attach to the computer.
USB Keyboard Requirements
USB (Universal Serial Bus) devices have become increasingly popular,
and over the next few years are expected to replace serial, parallel,
keyboard, and mouse port connectors with this single, versatile,
sharable port (refer to Chapter 8 for more information about USB).
To use a keyboard connected via the USB port, you must meet
three requirements:
• Have a USB port in the system
• Run Microsoft Windows 98, Windows Me, or Windows 2000
(all of which include USB keyboard drivers)
• Have USB Legacy support present and enabled in your system
BIOS
USB Legacy support means your motherboard ROM BIOS includes
drivers to recognize a USB keyboard. Without USB Legacy support
in the BIOS, you can’t use a USB keyboard when in MS-DOS or
when installing Windows on the system for the first time. Also, if
the Windows installation fails and requires manipulation outside
Windows, the USB keyboard will not function unless it is supported
in the BIOS. Virtually all 1998 and newer systems with USB ports
include a BIOS with USB Legacy (meaning USB Keyboard) support.
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
Keyboard Troubleshooting and Repair 227