IBM PC CONVERTIBLE Technical Reference page 75

0744 E6 75
0746
0746 C3
0747
0747
0747
0749
074B
074D
074F
0750
0750
0750
0752
0754
0756
0758
0759
0759
0759
075B
075D
075F
0761
0762
0762
0762
0765
0767
0769
076B
076D
076E
86 EO
E6 70
86 C4
E4 71
C3
86
EO
E6 70
86 C4
E6 71
C3
E4 61
8A EO
OC 04
E6 61
C3
80 E4 04
E4 61
24 FB
OA C4
E6 61
C3
50
BO 07
E6 72
EB 00
OC 20
OUT LCD_DATA,AL
LOW BEND :
RET
LOW_BALCHK ENDP
ISSUE LCDC CONTROL REG COMMAND
RETURN TO CALLER
; *****************************************************
; GET RTC REGISTER WHEN ON NMI LEVEL
; INPUT AH= REGISTER # OUTPUT AL
=
REGISTER DATA
; *****************************************************
GELRTCNMI PROC NEAR
XCHG AH,AL
OUT RTCR_PORT ,AL
OUTPUT REGISTER
#
XCHG AL ,AH
IN AL, RTCD_PORT GET DATA
RET
GELRTCNMI ENDP
; *****************************************************
; PUT RTC REGISTER WHEN ON NMI LEVEL
; INPUT AH= REGISTER #, AL
=
REGISTER DATA OUTPUT: RTC RAM MODIFIED
; *****************************************************
PULRTCNMI PROC NEAR
XCHG AH ,AL
OUT RTCR_PORT ,AL
XCHG AL ,AH
OUT RTCD_PORT, AL
RET
PULRTCNMI ENDP
; **********************************
; FORCE SPEAKER ENABLE ON
; ON EXIT AH HAS OLD SPEAKER CONDITION
; **********************************
SPKR_ON PROC NEAR
IN AL,NMLCNTL FORCE SPEAKER ON
MOV AH,AL
OR AL, EN_SPKR
OUT NMLCNTL,AL
RET
SPKR_ON ENDP
; **********************************
; RESTORE SPEAKER TO PREVIOUS STATE
; ON INPUT AH HAS OLD SPEAKER CONDITION
; **********************************
SPKfLRESTORE PROC NEAR
AND AH, EN_SPKR
IN AL,NMLCNTL
RESTORE SPEAKER CONTROL
AND AL, NOT EN_SPKR
OR AL,AH
OUT NMLCNTL,AL
RET
SPKR_RESTORE ENDP
; *******************************************
NMLCYCLE: THIS CODE DISABLES
AND RE-ENABLES THE NMI BEFORE RESTORING
THE INTERRUPT FLAGS TO THEIR PREVIOUS
STATE.
, ALL REGISTERS PRESERVED EXCEPT FLAGS
; ********************************************
NMLCYCLE PROC NEAR
PUSH AX ;
MOV AL, D I SA BL CSL E EP+CLOCICRUN
OUT CLOCICCTL ,AL
JMP $+2 DELAY
DISABLE GLOBAL NMI
OR AL, GLOBAL_NMI
RE-ENABLE NMI' S
076E
076E
076F
0771
0773
0775
0777
077C
077E
077F
077F
0781
0782
0783
F7 46 16 0200
74 01
TEST FLGSAVE [BP], LFLAG
JZ NMLCI
CHECK FOR INTERRUPTS ON
I F NOT THEN DON'T ENABLE
ALLOW I NTERRUPTS AFTER
FB
E6 72
58
C3
STI
NMLCI :
OUT
POP
RET
CLOCICCTL ,AL
AX
NMLCYCLE ENDP
ENABLE NMI INSTRUCTION
2-50 ROM BIOS