HT82K28A
5
February 16, 2000
Power-on
Twoimportantactivitiestakeplacewhenpower
is first applied to the keyboard. The first is the
presence of an H/W signal POR (Power-On-Re-
set) that resets the keyboard processor. The sec-
ond activity is the running of the self test BAT
(Basic Assurance Test) routine.
PC-type/mode/code set
The following table describes the relationship
between different computer types, the working
mode and the code sets.
PS/2 30
mode 1
code set 1
PC-AT
mode 2
code set 2
PS/2 50
mode 2
code set 2
PS/2 60
mode 2
code set 2
PS/2 80
mode 3
code set 3
Themodecanbechangedbetweenmode2&3.
Keys
For code set 1, 2
All keys except the PAUSE key have a make
and break code. The PAUSE key has a make
code only.
The defaults except for PAUSE are make/
break/typematic. In mode 1, 2 and 3 the key
type may be changed to be one of the follow-
ing:
Typematic
Make/break
Make
Typematic/make/break
All keys except PAUSE are typematic.
Typematic means that the KB keeps send-
ing make codes if the key is held down.
The data report is according to the
typematic rate/delay:
Default values are: delay 500ms
10.9 char/sec
20%
20%
The typematic rate and delay can be modi-
fied with the F3 command.
If two or more keys are held down, only the
last key pressed repeats at the typematic
rate.
Typematic operation stops when the last
key pressed is released even if other keys
are still held down.
If a key is pressed and held down while key-
board transmission is inhibited, only the
first make code is stored in the buffer over-
flow as a result of typematic action.
Four key types are supported as shown:
Key type
press
hold
release
Typematic
Make/break
Make
Typematic/
make/break
make1
make1
make1
make1
make2
X
X
make2
X
break
X
break
Note: "make1" send out only one make
code.
"Make2" continue sending out make
codes until key is released.
"X" nothing sent out.
For code set 3
Typematic
Make/break
Make
Typematic/make/break
Can be configured by command
Time interval between phantoms
The time interval between two continuous error
codes 00/FF sent while phantom detected=
1000ms
20%
! " # $ ! % $ #
' $ #(
' $ ! ) *
! (
! (
! (