IBM PC CONVERTIBLE

0203 58
0204 A2 0040 R
0207
0207
IE
0208 88 5E 12
020S 8S 46 14
020E 8E 08
0210 4B
0211 8A 07
0213 IF
0214 3C EC
0216 74 04
0218 3C EE
021A 75 03
021C
021C
FF 4E
12
021F
021F
E9 0050 R
0222
0222
51
0223 BA 03F4
0226
2B C9
0228
0228
EC
0229 A8 10
022B 74 02
0220 E2 F9
022F
022F
59
0230 C3
0231
0231
0231
51
0232
53
0233 B3 04
0235 2B C9
0237
POP AX ; RETRI EVE MOTOR COUNT
MOV MOTOILCOUNT , AL
ADJUST THE STACK POINTER TO RETURN TO USER
DSKLRSEXIT:
PUSH OS
MOV BX,OFFSAVE[BP]
MOV AX,SEGSAVE[BP]
MOV DS,AX
DEC BX
MOV AL, [BX]
POP OS
CMP AL,IN_INSTR
JE DSKLRHLADJ
CMP AL, DULl NSTR
JNE RHLEXITNMI
DSKLRTN-ADJ:
DEC OFFSAVE[BP]
RTN_EXITNMI:
JMP NMIH_EXIT
GET RETURN OFFSET AODR
GET RETURN SEGMENT AOOR
POINT BACK TO INSTR
GET INSTRUCTION BYTE
IN AL ,OX INSTRUCTION?
YES THEN ADJUST RETURN
OUT DX,AL INSTRUCTION?
NO TH EN DO NOT ADJUST RTN
SETUP TO REISSUE THE I/O FOR USER
RETURN TO NMLFLIH
;THIS ROUTINE WILL WAIT FOR THE FOC TO DROP BUSY
DROP_BUSY PROC NEAR
PUSH CX
MOV OX, FOCSTATUS
SUB CX,CX
WAILBUSY:
IN AL,OX
TEST AL, FDCBUSY
JZ FOCDONE
LOOP WAIT_BUSY
FOCDONE:
POP CX
RET
DROP_BUSY ENDP
SAVE REGISTER VALUE
POINT TO MASTER STATUS PORT
TIMING COUNT FOR LOOP
READ THE MASTER PORT
TEST FOR BUSY TO DROP
FDC NO LONGER I S BUSY
RESTORE ORIGINAL VALUE
;THIS ROUTINE WILL WAIT FOR AN INTERRUPT FROM THE FOC
WAILINTRPT PROC NEAR
PUSH
CX
PUSH
BX SAVE BX
MOV
BL,4 2 SECONDS WAIT
SUB CX,CX TIMING COUNT FOR LOOP
WAILINT:
0237 F6 06 003E R 80 TEST
SEEICSTATUS,INLFLAG WAIT FOR AN INTERRUPT
023C 75 06
JNZ FOCINTRPT FDC GENERATED AN INTERRUPT
023E E2 F7
LOOP WAILINT
0240 FE CB
DEC BL
0242 75 F3
JNZ WAILINT WAIT ON INTERRUPT
0244
FDCINTRPT:
0244 80 26 003E R 7F
AND SEEICSTATUS, NOT INLFLAG ; RESET THE INTERRUPT
FLAG
0249 5B
024A 59
024B C3
024C
024C
024C
024C
IE
0240 50
024E B8 ---- R
0251
8E 08
POP
BX RESTORE BX
POP
CX
RET
WAILINTRPT ENDP
DSKLRESYNC ENDP
DSKLINTE
THIS
ROUTINE HANDLES THE DISKETTE INTERRUPT
INPUT: NONE
OUTPUT: THE INTERRUPT FLAG SET IS SEEICSTATUS
DSKLNMIE
PUSH
PUSH
MOV
MOV
PROC FAR
OS
AX
AX,DATA
DS,AX
SET UP DATA SEGMENT
0253 80 OE 003E R 80
OR SEEICSTATUS, I NLFLAG
ROM BIOS 2-33