IBM PC CONVERTIBLE Technical Reference page 202

01M 8B OA MOV BX, OX RESTORE SYS PROF
01A6 5A POP OX SAVE REGISTER
SET LCD HIGH INTENSITY SUBSTITUTE
01A7 SELLCO_OPT:
01A7 53 PUSH
BX
SAVE BX REG
0lA8
8A OF MOV BL, BH
01AA
DO EB SHR BL,l
01AC DO EB
SHR BL,l
01AE 80 E3 03
AND BL,03H
SAVE ONLY LCD SUBSTITUTE TYP
01B1 B4 14
MOV AH,20
VIDEO FUNCTION CALL 20
01B3 BO 02 MOV
AL,2
SET LCD HIGH INTENSITY SUB
01B5 9C PUSHF
01B6 DE PUSH CS
01B7 E8 0000 E CALL VIDEO_IO_I
I NT 10 CALL
01BA 5B POP BX
RESTORE BX REG
01BB
SPROF_EXIT:
01BB 2A CO SUB AL,AL SET GOOD RETURN
OIBO SPROF _OUT:
01BO C3 RET
01BE
SYS_PROF
ENOP
External Event Services (EXT _EVENT)
INT 15H
ROUTINE-NAME: EXLEVENT (AH " 41H)
FUNCTION: TO WAIT FOR A SPECIFIC STATUS CHANGE AFTER AN EXT EVENT
(OMA OR INTERRUPT) WHILE KEEPING THE SYS CLKS STOPPED TO
CONSERVE BATTERY POWER.
ROM BIOS 2-177