IBM PC CONVERTIBLE Technical Reference page 153

01EF AC
01FO 00 EO
01F2 B4 04
01F4 72 24
01F6 DO ED
01F8 DO EO
01FA B4 10
01FC 72 lC
01FE DO EO
0200 B4 08
0202 72 16
0204 DO ED
0206 DO ED
0208 B4 04
020A 72 OE
020C DO EO
020E B4 03
0210 72 08
0212 DO EO
0214 B4 02
0216 72 02
0218
0218 B4 20
021A
021A 08 26 0041
021E E8 03F5 R
0221
0221 EB 08
0223
0223 E8 03B3
0226
EB 03
0228
0228 E8 03F5 R
022B
022B C3
022C
022C
022C 52
022D 51
022E BA 03F4
0231 33 C9
0233
0233 EC
0234 A8 40
0236 74 OE
0238 E2 F9
023A
LODS NELSTATUS GET STl
SAL AL,1 TEST FOR EDT FOUNO
MOV AH, RECORO_NOT _FND
JC J19
RW_FAIL
SAL AL,1
SAL AL,1 TEST FOR CRC ERROR
MOV
AH,BAD_CRC
JC J19 RWJAIL
SAL AL,1 TEST FOR DMA OVERRUN
MOV AH, BAD_DMA
JC J19
RW_FAIL
SAL AL,1
SAL AL,1 TEST FOR RECORD NOT FOUND
MOV
AH, RECORD_NOT JND
JC J19 RW_FAIL
SAL AL,1
MOV
AH, WRITE_PROTECT
TEST FOR WRITE_PROTECT
JC J19 RWJAIL
SAL AL,1 TEST MISSING ADDRESS MARK
MOV AH,
BAD--ADDR~ARK
JC J19 RWJAIL
NEC MUST HAVE FAILED
J18: RW-NEC-FAIL
MOV
AH,BAD_NEC
J19 : RW-FAIL
OR 01 SKETTE_STATUS ,AH
CALL NUM_TRANS
HOW MANY WERE REALLY TRANSFERRED
J20: RW_ERR
JMP SHORT RW_EX IT
RETURN TO CALLER
J21 : RW_ERR_RES
CALL RESUL TS FLUSH THE RESULTS BUFFER
JMP
SHORT RW_EXIT
OPERATION WAS SUCCESSFUL
J22 :
OPN_OK
CALL
NUM_TRANS
HOW MANY GOT MOVED
RW_EXIT:
RET
RW_OPN
ENDP
NECOUTPUT
INPUT
OUTPUT
THIS ROUTINE SENDS A BYTE TO THE NEC CONTROLLER AFTER TESTING
FOR CORRECT DIRECTION AND CONTROLLER REAOY THIS ROUTINE WILL
TIME OUT IF THE BYTE IS NOT ACCEPTEO WITHIN A REASONABLE
AMOUNT OF TIME, SETTING THE DISKETTE STATUS ON COMPLETION.
(AH) BYTE TO BE OUTPUT
CY
=
0 SUCCESS
CY
=
1 FAILURE -- DISKETTE STATUS UPOATED
IF A FAILURE HAS OCCURRED, THE RETURN IS MADE ONE LEVEL
HIGHER THAN THE CALLER OF NECOUTPUT.
THIS REMOVES THE REQUIREMENT OF TESTING AFTER EVERY
CALL OF NELOUTPUT.
(AL) DESTROYED
NECOUTPUT PROC NEAR
PUSH DX SAVE REGISTERS
PUSH CX
MOV DX, FDCSTATUS STATUS PORT
XOR CX,€X COUNT FOR TIME OUT
J23 :
IN AL, DX
GET STATUS
TEST AL,DATLREADY TEST DIRECTION BIT
JZ J25
DIRECTION OK
LOOP J23
J24:
TIME_ERROR
2-128 ROM BIOS