IBM AT 5170 Technical Reference page 269

IBM Personal Computer MACRO Assembler V.rsion 2.00 1- I
DSKETTE -- 06/'0/65 DISKETTE BIOS
06-' 0-65
I
PAGE " 6 , ' 2 '
2
TITLE DSKETTE -- 06/10/65 DISKETTE BIOS
3
.266C
4
.LIST
5 0000
CODE SEGMENT BYTE PUBL I C
.
6
7
PUBLIC DISK
INT I
8 PUBLIC SEEK- ­
PUBLIC DSKETTE SETUP
10
PUBLIC DISKETTE_'O_'
12
13
EXTRN DDS: NEAR
LOAD IDS) WITH DATA SEGMENT SELECTOR
14 EXTRN 0 I SK BASE ,NEAR DISKETTE PARAMETER TABLE LOCATION
IS
EXTRN WA ITF:NEAR FIXED WAIT ROUTINE - (CX) -'5.066 US
"
EXTRN CMOS READ1NEAR READ CMOS LOCATION RDUTINE
.. 16
17 INT '3H --- ----------------- -------------------------------------------­
18 DISKETTE I/O
THIS INTERFACE PROVIDES ACCESS TO THE
5 1/4~
DISKETTE DRIVES
20
320/360K
DISKETTE DRIVES AND 1.2104 DISKETTE DRIVES SUPPORTED
21 INPUT
22
(AH 1= OOH RESET 0 I SKETTE SYSTEM
23
HARD RESET TO NEC, PREPARE COMMAND, RECALIBRATE REQUIRED
24
ON ALL DR
I
VES
25
26
(AHI= 01H READ THE STATUS OF THE SYSTEM INTO (AHI
27
ODSKETTE_STATUS FROM LAST OPERATION IS USED
28
2' REGISTERS FOR READ/WRITE/VERIFY/FORMAT
30
(DLI - DRIVE NUMBER (0-1 ALLOWED, VALUE CHECKED)
31
(DHI - HEAD NUMBER (0-1 ALLOWED, NOT VALUE CHECKED)
32
(CHI - TRACK NUMBER INOT VALUE CHECKED)
33 MEDIA DRIVE TRACK NUMBER
34
320/360 320/360 0-39
35
320/360 1.2M 0-39
36
t.2M 1.2M 0-79
37
720K 72DK 0-79
38
(CL) - SECTOR NUMBER (NOT VALUE CHECKED, NOT US EO FOR FORMAT)
3.
MED
I
A DR [VE SECTOR NUMBER
40
320/360 320/360 1-8/9
41 320/360 1.2M 1-8/9
42
1.2M 1.2M 1-15
43
720K 720K 1-9
44
(AL) - NUMBER OF SECTORS (NOT VALUE CHECKED)
45 MEDIA DRIVE MAX NUMBER OF SECTORS
46
320/360 320/360 6/9
47
320/360 I.2M 8/9
48
1.2101 '.2104
15
49 720K 720K 9
50
5 I (ES: BX) - ADDRESS OF BUFFER
i
REQU I RED FOR VER I FY
I
52
53
54
(AH) = 02H READ THE DESIRED SECTORS INTO MEMORY
55
56 (AH) = 03H WR I TE THE DES I RED SECTORS FROM MEMORY
57
58
IAH)= 04H VERIFY THE DESIRED SECTORS
5'
60
(AH)
=
05H FORMAT THE DES[RED TRACK
61 FOR THE FORMAT OPERATION, THE BUFFER POINTER (ES,BX) MUST
62
POINT TO THE COLLECTION OF DESIRED ADDRESS FIELDS FOR THE
63
TRACK. EACH FIELD I S COMPOSED OF 4 BYTES, (C, H, R, N I, WHERE
64
C ;;: TRACK NUMBER, H;;:HEAD NUMBER. R "" SECTOR NUMBER. N;;: NUMBER
65
OF BYTES PER SECTOR (00=128, 01=256, 02=512. 03=1024,)
66 THERE MUST BE ONE ENTRY FOR EVERY SECTOR ON THE TRACK.
67
THI S INFORMATION IS USED TO FIND THE REQUESTED SECTOR OUR [NG
68
READ/WRITE ACCESS.
6'
PRIOR TO FORMATTING A DISKETTE, IF THERE EXISTS MORE THAN
70
ONE SUPPORTED MEDIA FORMAT TYPE WITHIN THE DRIVE IN QUESTION,
71
THEN "SET DASD TYPE" (INT 13H, AH = 17HI MUST BE CALLED TO
72
SET THE
0
I SKETTE TYPE THAT I S TO BE FORMATTED. IF" SET DASD
73
TYPE" IS NOT CALLED, THE FORMAT ROUTINE W[LL ASSUME THE
74
MEDIA FORMAT TO BE THE MAXIMUM CAPACITY OF THE DRIVE.
75
IN' ORDER TO FORMAT 320/360K MEDIA
[N
EITHER A 320/360K OR
76
I .2M D [SKETTE DR I VE THE GAP LENGTH FOR FORMAT PARAMETER
77
OF DISK BASE MUST BE CHANGE TO 050H. ALSO THE EOT
78
PARAMETER (LAST SECTOR ON TRACK) MUST BE SET TO THE
79
DESIRED NUMBER OF SECTORS/TRACK - 8 FOR 320K,
9
FOR 360K.
80
DISK BASE IS POINTED TO BY DISK POINTER LOCATED AT
81
ABSOLUTE ADDRESS 0:78.
82
WHEN 320/360K FORMAT OPERATIONS ARE COMPLETE. THE PARAMETERS
83
SHOULD BE RESTORED TO THEIR RESPECTIVE INITIAL VALUES.
84
85
IAH)= 08H READ DR[VE PARAMETERS
86
REG I STERS
87
INPUT
88 (DL) - DRIVE NUMBER (0-( ALLOWED. VALUE CHECKED)
8'
OUTPUT
'0
(ES=DI) POINTS TO DISK BASE
(CHI - LOW ORDER 8 OF 10 BITS MAXIMUM NUMBER OF TRACKS
"
. 2
(CLI - BITS 7 & 6 - HIGH ORDER TWO BITS OF MAXIMUM TRACKS
.3
- 81 TS 5 THRU 0 - MAX I MUM SECTORS PER TRACK
94
(DH) -
MAX [MUM HEAD NUMBER
95
(DLl NUMBER OF DISKETTE DRIVES INSTALLED
.6
(BHl - 0
97
(BLl - B[TS 7 THRU 4 - 0
'8 elTs 3
THRU 0 VALID DRIVE TYPE VALUE IN CMOS
..
(AX) 0
100
UNDER THE FOLLOWING CIRCUMSTANCES:
101
'1) THE DRIVE NUMBER IS I NVA1...I0,
102
(21 THE DRIVE TYPE IS UNKNOWN AND CMOS IS NOT PRESENT,
103
(31 THE DR I VE TYPE I S UNKNOWN AND CMOS I S BAD,
104
(4) OR THE DRIVE TYPE IS UNKNOWN AND THE CMOS DR[VE TYPE IS INVALID
105
THEN,ES,AX,BX,CX,DH,DI;;:O ; DL;;:NUh4BER OF DR[VES.
10.
IF NO DRIVES ARE PRESENT THEN: ES,AX,BX,CX,DX,DI:O.
107
@DSKETTE_STATUS
=
0 AND CY I S RESET.
DISKETTE 5-97