IBM PC CONVERTIBLE

OOFA E4 21 IN AL,INTAOI
OOFC 24 BF AND AL ,OBFH ; ENABLE DISKETTE
INTERRUPTS
OOFE E6 21 OUT INTAOl,AL
~ SETUP TO READ THE TRACK COUNTERS AND DEGATE 01 SKETTES
0100 BO EA MOV
AL, DSKLNMI tFDCPWR+DSKT _DEGATE+DRO_TRLSEL +CNTLSEL
0102
E6 77 OUT DSKLCNTL, AL
0104 E4 77 IN AL,DSKLCNTL
; READ THE TRACK CNTR FOR DR 0
0106
8A C8 MOV CL,AL ; CL <-- DRIVE 0 POSITION
0108 BO E2 MOV
AL, DSKT _NMI +FDCPWR+DSKT _DEGATE+CNTL_SEL
010A E6 77 OUT DSKLCNTL,AL
OlOC E4 77 IN AL,DSKLCNTL
; READ THE TRACK COUNTER FOR DR
OlOE 8A E8 MOV CH,AL ; CH <--- DRIVE 1 POSITION
0110 BO F2 MOV
AL, DSKLNMI +FDCPWR+DSKT _DEGATE+RD_CNTL +CNTL_SEL
0112 E6 77 OUT DSKT _CNTL, AL
RESET THE FOC AND ISSUE SPECIFY COMMAND TO THE FDC
CH = DRIVE 1 TRACK POSITION, CL= DRIVE 0, BL = DRIVE_SENSE ON NMI ENTRY
0114 8A C3 MOV AL,BL
0116 24 10 AND
AL , ORO_MOTOR SAVE ORO MOTOR STATE
0118 F6 C3 08 TEST BL,DRL.MOLSENSE
WAS DRIVE 1 MOTOR ON?
011B 74 02
JZ NMLSELMOT
NO THEN JUMP
0110 OC 20
OR AL,DRLMOTOR
OTHERWISE TURN ON DRIVE 1 MOTOR
011F
NMLSELMOT:
011F OC 08 OR AL, FDCDMILENAB ENABLE DMA/INTERRUPTS BIT
0121 F6 C3 20 TEST BL,DRLSEL_SENSE DRIVE 1 ACTIVE ?
0124 74 02
JZ
NMLSELDR JUMP I F NOT
0126 OC 01 OR AL,DRLSELECT
0128
NMLSELDR:
0128 BA 03F2 MOV OX, DR I V E_CNTL
012B EE OUT DX,AL RESET THE ADAPTER
012C OC 04 OR AL, FDCRUN TURN OFF THE RESET
012E EB 00 JMP $ + 2 TIME DELAY
0130 EE OUT DX,AL
0131 80 26 003E R 7F AND SEELSTATUS,NOT
INLFLAG ; RESET THE
I NTERRUPT FLAG
0136 FB STI ALLOW INTERRUPTS
0137 EB 0231 R CALL WAILINTRPT
CHECK FOR FDC TO GENERATE AN INT
013A BF 01F4 R MOV
DI,OFFSET RESYNCOUT2
ERROR EXIT FOR NECOUTPUT
0130 57 PUSH
01
013E 8B F9 MOV
DI,CX
SAVE TRACK COUNTERS
0140 B9 0004 MOV
CX,4
READ 4 DRIVES STATUS
0143 NMLRSETLP:
0143 B4 08 MOV AH ,READ_INLSTATUS READ INTERRUPT STATUS COMMAND
0145 E8 0000
CALL NECOUTPUT
SEND IT TO THE FDC
0148 E8 0000 CALL
RESULTS
GET STO AND PCN
014B
E2 F6
LOOP NMLRSETLP LOOP UNTI L COMPLETE
0140
NMLSPECI
FY:
0140 8B CF
MOV CX,DI RESTORE TRACK COUNTERS
014F B4 03
MOV AH, SPECI FY SPECIFY COMMAND
0151 E8 0000
CALL NECOUTPUT
0154 BB 0001
MOV BX,1
FIRST PARM SENT TO THE
FDC
0157 E8 0000
CALL GELPARM
015A E8 0000
CALL NECOUTPUT
0150
BB 0003 MOV BX ,03H SECOND PARM SENT TO THE FOC
0160 E8 0000 E
CALL GELPARM
0163
E8 0000 E CALL NECOUTPUT
0166 E8 0222 R
CALL
DROP _BUSY
ISSUE OVERLAPPED RECALS TO DR 0 AND 1 IF INSTALLED
NOTE SEE WHAT TO DO WITH SEELSTATUS BIT 7-INTERRUPT RECEIVED
0169 B4 07
MOV AH, RECALl BRATE RECAL COMMAND FOR THE FDC
016B E8 0000 E
CALL NECOUTPUT OUTPUT IT TO THE FDC
016E B4 00
MOV AH,OO RECAL DRI VE 0 FI RST
0170 E8 0000 E
CALL NECOUTPUT OUTPUT IT TO THE FDC
0173 E8 0222 R
CALL
DROP_BUSY
CHK FOR FDC BUSY TO DROP FOR OVLP
,
;SEE IF THERE IS A SECOND DRIVE I F SO RECAL IT
0176
F7 06 ooui R 0040 TEST EQU I P _FLAG, 40H
; SEE IF SECOND DRIVE IS INSTALLED
017C
74 OA JZ RECAL_DONE
; ONLY DRIVE 0 INSTALLED
ROM BIOS 2-31