IBM 5170 Technical Reference page 245

TITLE FIXED DISK BIOS FOR IBM DISK CONTROllER 1-11-84
DOFF
ODED
OOCC
OOBB
OOAA
0080
0040
PUBLIC DISK 10
PUBLIC HD_INT
PUBl l e D I SK_SETU
r
EXTRN F178D: NEAR
EXTRN F1781 : NEAR
EXTRN F17K2: NEAR
EXTRN F17<JO: NEAR
EXTRN F1791: NEAR
EXTRN FD TBl; NEAR
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F I XED DISK I/O INTERFACE
HilS INTERFACE PROVID[S ACCESS TO 5 1/4" fiXED DISKS
THROUGH THE IBM FIXED DISK CONTROllER.
TIlE BIOS ROUTINES ARE MEANT TO BE ACCESSED THROUGH
SOFTWARE I NTERRUPTS ONLY. ANY ADDRESSES PRESENT IN
TIlE LISTINGS ARE INCLUDED ONLY FOR COMPLETENESS,
NO r FOR RE FERENCE. APPl I CAT IONS WH I CH REFERENCE
ABSOLUTE ADDRESSES WITHIN THE CODE SEGMENT
VIOLATE THE STRUCTURE AND DESIGN OF BIOS.
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INPUT (AH"" HEX VALUE)
(AH)"OO RESET DISK (Dl:. BOH,alH) / DISKETTE
(AH)=Ol HEAD THE STATUS OF THE LAST DISK OPERATION INTO (Al)
NOTE: Dl
<
BOH - DISKETTE
Dl
>
80H - 0 I SK
(AH)=02 READ THE DESIRED SECTORS INTO MEMORY
(AH)=03 WRITE THE DESIRED SECTORS FROM MEMORY
(AH)=04 VERifY THE DESIRED SECTORS
(AH)=05 FORMAT TIlE DESIRED TRACK
(AH)=06 UNUSED
(AH)::=07 UNUSED
(AH)=08 RETURN THE CURRENT DRIVE PARAMETERS
(AHj=09 INITIALIZE DRIVE PAIR CHARACTERISTICS
INTERRUPT 41 POINTS TO DATA BLOCK fOR DRIVE a
INTERRUPT 46 POINTS TO DATA BLOCK FOR DRIVE 1
(AH)=OA READ lONG
(AH)'=OB WRITE lONG
NOTE: READ AND WRITE lONG ENCOMPASS 512 + 4 BYTES ECC
(AH )=OC SEEK
(AHl=OD ALTERNATE DISK RESET (SEE Dl)
(AHj"'OE UNUSED
(AHj=Of UNUSED
(AH)=10 TEST DRIVE READY
(AH)=11 RECAlIBRAl[
(AH )=12 UNUSED
(AIi)"'13 UNUSED
(AHj=14 CONTROllER INTERNAL DIAGNOSTIC
(AH)=15 READ DASD TYPE
~AGE
REGISTERS USED FOR FIXED DISK OPERATIONS
(Dl) DRIVE NUMBER (80H-B1H FOR DISK, VALUE CHECKED)
(DH) HEAD NUMBER (0-15 AllOWED, NOT VALUE CHECKED)
(CH) CYLINDER NUMBER (0-1023, NOT VALUE CHECKED)(SEE Cll
(Cl) SECTOR NUMBER ( 1- 17, NOT VALUE CHECKED)
NOTE: HIGH 2 BITS OF CYLINDER NUMBER ARE PLACED
IN THE HIGH 2 BITS Of THE Cl REGISTER
(10 BITS TOTAL)
(Al) NUMBER OF SECTORS (MAXIMUM POSSIBLE RANGE l-BOH,
FOR READ/WRITE lONG
1~79H)
(ES;BX) ADDRESS OF BUFfER FOR READS AND WRITES,
(NOT REQu I RED FOR VER I FY)
FORMAT
(AH=~)
ES:BX POINTS TO A 512 BYTE BUFFER. THE FIRST
2 .... ( SECTORS/TRACK) BYTES CONTA I N F, N FOR EACH SECTOR.
F =
~OH
FOR A GOOD SECTOR
BOH fOR A BAD SECTOR
N = SECTOR NUMBER
FOR AN I NTERlEAVE OF 2 AND 17 SECTORS/TRACK
THE TABLE SHOULD BE:
DB DOH, 01 H, DOH, OAH, OOH, 02H, OOH, OBH,
~OH,
03H, OOH, OCH
DB DOH, 04H, OOH, DOH, OOH, a5H, DOH, OEH,
~OH,
06H, DOH. OfH
DB OOH,07H,OOH, lOH, DOH, OSH,OOH, 11 H, DOH, D9H
OUTPUT
AH "" STATUS OF CURRENT OPERAT ION
STATUS BITS ARE DEFINED IN THE EQUArES BELOW
CY = a SUCCESSFUL OPERATION (AH=O ON RETURN)
CY = 1 fAI lED OPERAT ION (AH HAS ERROR REASON)
NOTE: ERROR 11H INDICATES THAT THE DATA READ HAD A RECOVERABLE
ERROR WHICH WAS CORRECTED BY THE ECC ALGORITHM. THE DATA
IS PROBABLY GOOD, HOWEVER THE BIDS ROUTINE INDICATES AN
ERROR TO AllOW THE CONTROlliNG PROGRAM A CHANCE TO DECIDE
FOR ITSELF. THE ERROR MAY NOT RECUR If THE DATA IS
REWR I TTEN.
I F DRIVE PARAMETERS WERE REQUESTED,
DL
=
NUMBER OF CONSECUTIVE ACKNOWLEDGING DRIVES ATTACHED (0-2)
(CONTROllER CARD ZERO TAllY ONLY)
DH = MAXIMUM USEABLE VALUE FOR HEAD NUMBER
CH'" MAXIMUM USEABLE VALUE FOR CYLINDER NUMBER
Cl
:=
MAX I MUM USEABLE VALUE FOR SECTOR NUMBER
AND CYLINDER NUMBER HIGH BITS
I FREAD DAsa TYPE WAS REQUESTED,
AH
=
0 - NOT PRESENT
, - 0 I SKETTE - NO CHANGE liNE AVA I LABlE
2 - DISKETTE - CHANGE liNE AVA I LABlE
3 - FIXED DISK
CX,DX:= NUMBER OF 512 BYTE BLOCKS WHEN AH = 3
REGISTERS Will BE PRESERVED EXCEPT WHEN THEY ARE USED TO RETURN
INFORMATION.
NOTE: IF AN ERROR IS REPORTED BY THE DISK CODE, THE APPROPRIATE
ACTION IS TO RESET THE DISK, THEN RETRY THE OPERATION.
~ENSE
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;-NO~ -~ ~ ;L~~EN~ED -~--
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NO_ERR EQU OEOH ; STATUS ERROR/ERROR RCG==O
WRITE FAULT EQU OCCH ; WRITE FAULT ON SELECTED DRIVE
UNDECERR EQu OBBH ; UNDEF I NED ERROR OCCURRED
NOT ROY EQU OAAH DR I VE NOT READY
TIME OUT EQU 80H ATTACHMENT FAilED TO RESPOND
BAD_SEEK EQU 40H SEEK OPERATION fAilED
Disk 5-103