IBM PC CONVERTIBLE

02F8 AO 00B9
02FB 3C 00
02FD 74 09
02FF E6 60
THIS NMI IS A RESULT OF INT9 CLEARING THE KEYBOARD INDICATING THAT
THE PORT 60 SCAN CODE HAS BEEN READ AND IS READY TO ACCEPT ANOTHER.
KEYPAD /, * AND RIGHT -ALT NMI SCAN CODES GENERATE TWO CODES FOR PORT 60.
KYBD_XLT SENDS THE FIRST (HIDDEN CODE) DIRECTLY AND QUEUES THE SECOND
(P60 SCAN CODE) IN P60_HOLD_BYTE. IF P60_HOLD_BYTE IS HOLDING, IT MUST
BE SENT TO P60 AS SOON AS P60 IS EMPTY.
AL, P60_HOLD_BYTE GET HOLD BYTE
AL,NO_HOLD IS A SCAN CODE QUEUED?
KClO NO, JUMP.
KLDATA,AL ; HELD SCAN CODE TO P60
0301 C6 06 00B9 R 00
MOV
CMP
JE
OUT
MOV
JMP
P6LHOLD_BYTE,NO_HOLD ; RESET HOLD BYTE
0306 EB 05 SHORT KC20 ; LEAVE P60_LOADED SET
0308 80 26 00B4 R 7F KCI0 : AND KB_NMLCNTL ,NOT P60_LOADED ; SET OFF PRT 60 ACT
030D E4 61
030F 24 7F
0311
E6 61
;
0313
E8 0319 R
0316 E9 0050 R
0319
RESET CLEAR KEYBOARD NMI SOURCE
KC20 :
AND
OUT
IN AL,NMLCNTL
AL, NOT CLR_KEYBD
NMLCNTL,AL
GET NMI CONTROL PORT
SET CLEAR KYBD BIT TO 0
CALL TRANSLATE TO SEE IF ANYTHING IN QUEUE AND TRANSLATE IF SO
CALL
JMP
KYBD_XL T
NMIH_EXIT
XLATE AND WRITE TO PORT 60
GO TO 1ST LEVEL INTERRUPT HANDLER
PROCEDURE END
Translate Scan Code (KYBD_XL T)
0319
; *******************************************************************
KYBD_XLT - KEYBOARD SCAN CODE XLATE ROUTINE
DESCRIPTION:
IF THE SCAN CODE BUFFER IS EMPTY OR PORT 60H IS LOADED AT ENTRY
THEN THIS ROUTINE ENABLES KEYBOARD NMI AND EXITS.
IF THE BUFFER IS NOT EMPTY THE NEXT ENTRY IN THE
SCAN CODE BUFFER IS PROCESSED. THE SCAN CODE IS TRANSLATED TO THE
PCl EQUIVALENT AND THE PCl SCAN CODE IS WRITTEN TO PORT 60. HARDWARE
WILL GENERATE A SET HARDWARE INTERRUPT 1 REQUEST WHEN PORT 60 IS
WRITTEN. I F THE TRANSLATION DOES NOT RESULT IN A PORT 60 LOAD THEN
OTHER KEYS IN THE QUEUE ARE PROCESSED I F ANY.
INPUT: KB_NMLBUFFER
OUTPUT: WRITE TO PORT 60H
INTERNAL ROUTINES: NUM_STATCFIX
EXTERNAL ROUTINES: NMLCYCLE
REGISTERS MODIFIED: N/A
INTERRUPTS: I FLAG RESTORED TO PRE-NMI STATE
KYBD_NMI ENABLED
, NORMAL EX IT: RET
; ******************************************************************
NEAR
2~38 ROM BIOS