IBM PC CONVERTIBLE Technical Reference page 212

03BF 06 PUSH
ES SAVE REGISTERS
03CO 57 PUSH 01
03C1 53 PUSH BX
03C2 IE PUSH OS SET ES TO DATA SEGMENT
03C3 07 POP ES
03C4 8B 3E 0098 R MOV 01 ,USER_FLAG GET POSTED BYTE ADDR IN ES:DI
03C8 BO 03 MOV
AL,03 SET TEST & RTRN I F NOT ZERO
03CA B7 80 MOV BH, POSTED SET RTRN FOR INTERVAL POSTED
03CC
2A DB SUB
BL,BL SET NO TIME LIMIT
03CE E8 01BE R CALL
EXLEVENT WAIT ON EVENT
TIME HAS ELAPSED, RESTORE REGISTERS AND TURN OF PERIODIC INTERRUPT
0301 5B POP BX
; RESTORE REGISTERS
0302 5F
POP 01
0303 07 POP ES
0304 80 26 OOAO R 7E
AND RTCWAILFLAG, NOT POSTED+ INTERVAL_WAIT RST FUNCT
0309 F8
CLC
03DA
WINTLEXIT:
030A C3 RET
03DB WAILINTV
ENDP
Device Busy Services (DEV _BUSY)
INT 15H
ROUTINE-NAME: DELBUSY (AH
=
90H)
FUNCTION: THIS ROUTINE IS CALLED TO INDICATE THAT A DEV IS BUSY.
FOR THE DEVICE TYPE
=
DISKETTE, A RTRN IS NOT MADE UNTIL
A DISKETTE INTERRUPT HAS BEEN RECEIVED OR 2 SECONDS HAVE
ELAPSED (WHICHEVER IS FIRST). FOR THE DEV TYPE
=
KYBRD A
RETURN WILL NOT BE MADE UNTIL T*HE KYBD BFR IS IN A NOT
EMPTY CONDITION.
ENTRY IEXIT
CONDITIONS:
INPUT:
AL
=
DEVICE TYPE:
01 - DISKETTE
02 - KEYBOARD
FD - WAIT FOR
MOTOR STARTUP
RETURN AFTER IRPT RECEIVED OR 2
SECOND TIMEOUT HAS OCCURRED CARRY
SET I F TIMEOUT
RETURN WHEN KEYBOARD
BUFFER HEAD
<>
BUFFER TAIL
RETURN WHEN TIME HAS EXPIRED IF
TIMER 0 IS RUNNING OR IMMEDIATE
RETURN WHEN NOT RUNN I NG ON ENTRY CH
CONTAINS TIME TO WAIT IN 1/8 SEC
UNITS
ALL OTHERS
REGISTERS
MODIFIED:
IMMEDIATE RETURN WITH CARRY CLEAR
AX
ROM BIOS 2-187