Hardware Reference
In-Depth Information
The alternative keyboard layouts also do not provide support for non-Roman alphabets,
such as Russian and Chinese. The accented characters and other symbols used in lan-
guages such as French and German are part of the standard ASCII character set. They are
always accessible to English-language users through the Windows Character Map utility
or through the use of Alt+keypad combinations. An alternative keyboard layout simply
gives you an easier way to access the characters used in certain languages.
If you work on documents using more than one language, you can install as many key-
board layouts as necessary and switch between them at will. Using the settings in the Re-
gional and Language Options applet, you can enable both a selector in the taskbar noti-
fication area as well as a key combination that switches between the installed keyboard
layouts.
Keyboard/Mouse Interface Connectors
Keyboards typically have a cable with one of three primary types of connectors at the
system end. On most aftermarket keyboards, the cable is connected inside the keyboard
case onthekeyboardend,requiring youtoopenthekeyboardcase todisconnect ortest it;
vendorsusedifferentconnections,makingcableinterchangebetweenbrandsofkeyboards
unlikely. When IBM manufactured its own enhanced keyboards, it used a unique cable
assembly that plugged into both the keyboard and the system unit to make cable replace-
ment or interchange easy. Current IBM keyboards, unfortunately, no longer use either the
shielded data link (SDL) connector inside the keyboard or the telephone cable-style re-
movable plug-in external keyboard connector used on some more recent models.
Although the method of connecting the keyboard cable to the keyboard can vary (some
even use wireless connections), all PC keyboards use one of the following three connect-
ors to interface the keyboard (or wireless transceiver) to the computer:
•
5-pin DIN connector
—Usedonmostobsolete PCsystemswithBaby-ATformfactor
motherboards.
•
6-pin mini-DIN connector
—Often called a PS/2 connector because it was first used
on IBM PS/2 systems.
•
USB connector
—Most recent systems use USB keyboards and mice.
Figure 15.8
and
Table 15.2
show the physical layout and pinouts of the respective key-
boardconnectorplugsandsockets(exceptUSB);althoughthe6-pinSDLconnectorisnot
used in this form by most keyboard vendors, most non-IBM keyboards use a somewhat
similar connector to attach the keyboard cable to the inside of the keyboard. You can use
thepinoutslistedin
Table15.2
totestthecontinuityofeachwireinthekeyboardconnect-
or.
