IBM PC CONVERTIBLE

04E3
DSKLREADDASD
INPUT PARAMETERS:
AH = 15H
Dl = DRIVE NUMBER (0-3)
OUTPUT PARAMETERS:
AH = 00 - NO DRIVE PRESENT
01 - DISKETTE DRVIE WITH NO CHANGE LINE SUPPORT INSTAllED
02 - DISKETTE DRIVE WITH CHANGE LINE SUPPORT INSTAllED
03 - FIXED DISK
DISKETTLSTATUS = 0
DSKLRDDASD PROC NEAR
04E3 80 OE 0016 R 04
OR BIOS_STATUS,DCl_SUPPORTED ; SET CHANGE LINE
04E8 C6 06 0041 R 00
04ED E8 0586 R
04FO B4 00
04F2 3C 00
04F4 74 OB
04F6 3C 03
04F8 74 05
MOV
CAll
MOV
CMP
JE
CMP
JE
DISKETTLSTATUS,O
GELDRLCONFIG
AH,O
Al,NO_DRIVE
DASD_EXIT
Al, TPL135
DASD_Ol
SET NO CHANGE LINE AVAILABLE
04FA B4 01 MOV AH,OI
04FC
EB 03 90
JMP
DASD_EXIT
SET CHANGE LINE AVAILABLE
04FF DASD_Ol :
04FF
B4 02 MOV AH,02
0501
DASD_EXIT :
0501 88 66 OF MOV AHSAVE[BP] ,AH
0504 83 C4 02 ADD SP,2
0507
F8
ClC
0508
E9 0071
JMP
DIO_3
050B
DSKLRDDASD ENDP
SUPPORTED FLAG
SET GOOD RETURN CODE
GET DRIVE CONFIGURATION
CLEAR RETURN CODE
CHECK FOR DRIVE PRESENT
JUMP I F NOT PRESENT
3 1/2 DRIVES?
YES THEN JUMP
SET NO CHANGE LINE AVAIL
CHANGE LINE AVAILABLE
SAVE VALUE IN AH SAVE AREA
THROW AWAY RETURN ADDRESS
GO BACK TO MAIN ROUTINE
; *******************************************************************
050B
050B
E8 0586 R
050E OA CO
0510 74 41
0512 3C 03
0514 75 63
0516 E8 041B R
0519
0519
52
051A BA 03F4
0510 EC
051E BA 03 F7
0521 EC
0522 5A
0523
A8 80
0525
75 OF
;DISKETTE CHANGE lINE STATUS ROUTINE
; *******************************************************************
DSKLCHANGE PROC NEAR
CAll GELDRVJONFIG
OR Al,Al
JZ DCl_06
CMP Al, TP L135
JNE DCLI0
CAll MOTOILSTARTUP
CHECK CHANGE LINE
DCl_Ol :
PUSH OX
MOV OX, FDCSTATUS
IN Al,DX
MOV DX,DRIVE_SENSE
IN Al,DX
POP OX
TEST Al,CHG_LINE
JNZ
DCl_03
GET DRIVE CONFIGURATION
CHECK FOR DRIVE NO THERE
IF SO THEN SET TIMEOUT STATUS
CHECK FOR 3.5
JUMP IF NO CHANGE lINE
TURN ON MOTOR AND SELECT
ENSURE CONTROllER IS ON
DIGITAL INPUT PORT
RESTORE DRIVE NUMBER
TEST FOR DISKETTE CHANGE
; JUMP IF ACTIVE
0527
F6 06 0016 R 02
TEST BIOS_STATUS, FORCLDCl ; FORCE CHANGE ERROR
052C 75 2C JNZ
DCl_07
CHANGE LINE NOT ACTIVE
052E
DCl_02:
052E
C6 06 0041 R 00
MOV
ClC
JMP
DISKETTE_STATUS,O
SHORT DCl_EXIT
0533
F8
0534 EB 49
CHANGE LINE ACTIVE
; AFTER RESUME? - JUMP
SET GOOD RETURN
RESET ERROR FLAG
RETURN
IF YES
ROM BIOS 2-137