IBM PC CONVERTIBLE Technical Reference page 73

0663 A8 40
AL, LOWBALENABLE ; LOW BATTERY MESSAGE WANTED
0665 74 OF
LO ; NO MESSAGE WANTED - JUMP TO END
0667 F6 06 0015 R 20
TEST
JZ
TEST
JNZ
OR
JMP
BALSTATUS,LOW_BALPEND ; FIRST LOW BAT SIGNAL?
066C 75 23
Ll ; NO, ALREADY 2 CONSECUTIVE SIGNALS
066E 80 OE 0015 R 20
BALSTATUS,LOW_BALPEND ; YES, SET WAITING FOR 2ND SIG
0673 E9 0746 R
LOWBEND ; EXIT
0676 LO:
BATTERY NOT LOW OR EXTERNAL POWER IS APPLIED
0676 F6 06 0015 R 80
TEST
JNZ
AND
JMP
BALSTATUS,LOW_BALSIG ; WAS LOW BTRY ALREADY SIGNALLED
067B 75 08
LO--A ; YES, JUMP
0670 80 26 0015 R OF
BALSTATUS,NOT LOW_BALPEND ; TURN OFF LOW BTRY PENDING
0682 E9 0746 R
0685
0685 A8 40
0687 74 08
LOWBEND ; JUMP TO EX IT
LO--A :
LOW BATTERY HAS BEEN SIGNALLED. IF EXTERNAL PWR APPLIED RESET THE WARNING.
TEST
JZ
AL, EXLPWR
Ll
; IS EXTERANL POWER APPLI ED?
; NO, JUMP TO WARNING
BATTERY WAS LOW BUT EXTERNAL POWER APPLIED.
TURN OFF WAITING FOR KEY AND LOW BATTERY WARNING SIGNALED FLAGS.
JUMP TO TURN ON PANEL POWER.
0689 80 26 0015 R IF AND
JMP
BALSTATUS, NOT LOW_BAT _SI G+LOW_BAT _HOLD+LOW_BAT _PEND;
068E E9 073C R L_PANEL_ON ; ENABLE PANEL BEFORE EXITING
BATTERY IS LOW WITH NO EXTERNAL POWER AND WARNING ENABLED
0691
Ll:
0691 F6 06 0015 R 80 TEST
JZ
BALSTATUS,LOW_BALSIG ; LOW BTRY ALREADY SIGNALLED?
0696 74 2B
L3
NO, GO SIGNAL LOW BATTERY
LOW BATTERY HAS ALREADY BEEN SIGNALLED
0698 F6 06 0015 R 40 TEST
JZ
BALSTATUS,LOW_BALHOLD ; ARE WE IN HOLD STATE ?
0690 74 OC
069F BO 00
06Al E6 74
06A3 E4 75
06A5 34 40
06A7 OC 20
06A9 E6 75
06AB
06AB FE OE 0093
06AF 74 03
06Bl E9 0746 R
06B4 F6 06 0015
06B9 74 08
06BB 80 26 0015
06CO E9 0746 R
06C3
06C3 BO OB
06C5 E6 20
06C7 E4 20
06C9 OA CO
06C8 74 06
L2 ; NO, JUMP AROUND SCREEN TOGGLING
TOGGLE SCREEN ON AND OFF WHILE WAITING FOR A KEY TO BE PRESSED(HOLD STATE).
MOV
AL,LCD_FUNCT
OUT
LCD_INDX ,AL
ACCESS LCDC CONTROL REGISTER
IN AL,LCD_DATA READ LCDC CONTROL REGISTER
XOR
AL, PANEL_ENABLE
TOGGLE PANEL ON AND OFF
OR AL, SYNCENABLE FORCE SYNCS ON
OUT
LCD_DATA,AL
ISSUE LCDC CONTROL REG COMMAND
DECREMENT 2 MINUTE COUNTER. IF COUNTER GOES TO 0 SIGNAL LOW BATTERY
WARN I NG AGAI N I F KEY HAS BEEN PRESSED. I F COUNTER
=
0 AND A KEY HAS NOT
BEEN PRESSED, TURN OFF WAITING FOR KEY FLAG. THIS WILL CAUSE THE WAITING
FOR KEY LOOP TO BE EXITED AND THEN SET UP THE SYSTEM TO SUSPEND.
L2:
DEC
LOW_BALCTR
COUNT DOWN 2 MINUTE COUNTER
JFNZ LOWBEND NOT 0, SO EXIT
JZ $+5
I F NOT NOT ZERO JUMP AROUND JUMP
JMP LOWBEND ; ELSE TAKE A LONG JUMP
R 40 TEST BALSTATUS,LOW_BALHOLD ; HAS KEY BEEN PRESSED?
JZ L3 ; YES, SIGNAL WARNING AGAIN
R 3F AND BALSTATUS,NOT LOW_BALSIG + LOW_BALHOLD ; NO KEY,
JMP LOWBEND ; TURN OFF FLAG AND EXIT
SIGNAL LOW BATTERY WARNING
CHECK FOR ANY INTERRUPTS IN SERVICE BEFORE SIGNALING LOW BATTERY
L3:
MOV AL,OBH GET INTERRUPT IN SERVICE REG
OUT INTAOO,AL INTERRUPT CONTROLL ER PORT
IN AL,INTAOO READ INTERRUPT IN SERVICE REG
OR AL,AL ANY INTERRUPTS IN SERVICE
JZ L4 IF ZERO - NONE IN SERVICE
2-48 ROM BIOS