Hardware Reference
In-Depth Information
MODE CON: RATE=0 DELAY=3
Entering
MODE CON:
with no other parameters shows the current status of the settings. You
can also modify these settings using the Keyboard icon in the Control Panel. The Repeat
Delay slider, shown in
Figure 15.7
,
controls the duration for which you must press a key
before the character begins to repeat, and the Repeat Rate slider controls how fast the
character repeats after the delay has elapsed.
Figure 15.7
Setting the keyboard repeat delay and repeat rate in Windows XP (left) and Windows 7 (right).
Note
The increments on the Repeat Delay and Repeat Rate sliders in Keyboard Properties in the
Control Panel correspond to the timings given for the
MODE
command's
RATE
and
DELAY
values. Each mark in the Repeat Delay slider adds about 0.25 seconds to the delay, and the
marks in the Repeat Rate slider are worth about one character per second (1cps) each.
The dialog box also contains a text box you can use to test the settings you have chosen
before committing them to your system. When you click in the box and press a key, the
keyboard reacts using the settings currently specified by the sliders, even if you have not
yet applied the changes to the Windows environment.
Keyboard Key Numbers and Scan Codes
When you press a key on the keyboard, the processor built in to the keyboard (8048 or
6805 type) reads the keyswitch location in the keyboard matrix. The processor then sends
