6101778@PUCC.BITNET (Angus Christie) (01/06/87)
Uh huh. And I even PARKed it first. Oh well. The question is does anyone have any specs on the BIOS interrupt(s) which talk directly to the hard drive controller card? When I boot from a floppy (as I am forced to do), the system insists that drive C: is an invalid drive specifier. What I hope to do is read as much of the root directory and FAT as I can onto a floppy, then reFORMAT the thing, then try to restore the sectors. Am I doing the right thing? Am I asking lots of stupid questions? Am I whining? Thanks for listening, anyway.
brown@nicmad.UUCP (Mr. Video) (01/09/87)
In article <1514@PUCC.BITNET> 6101778@PUCC.BITNET writes: >Uh huh. And I even PARKed it first. Oh well. The question is >does anyone have any specs on the BIOS interrupt(s) which talk >directly to the hard drive controller card? When I boot from a >floppy (as I am forced to do), the system insists that drive C: >is an invalid drive specifier. What I hope to do is read as much >of the root directory and FAT as I can onto a floppy, then reFORMAT >the thing, then try to restore the sectors. > >Am I doing the right thing? Am I asking lots of stupid questions? >Am I whining? Thanks for listening, anyway. Attached below in my interrupt 13h assembly language program, complete with comments on what does what. It is part of DISKREAD program that I distributed a while ago. Anyway, I suspect that your disk partition table is bad. My program would show that to you. Unfortunately I haven't made my program writable to sectors yet, like Norton's does. But the program I made does allow the moving of a sector from one place to another, like another hard drive. Copy the partition table from one good drive to another and you will probably be ok. But I suspect that won't be the case. It may also be that you are getting errors from the drive and the data is really ok. Running my program will also report errors reported back from the hard drive controller. Let me know if you want the complete program. In the meantime, the data you wanted is below. Good luck. Mike Brown TITLE INT13 PAGE ,132 ;******************************************************************** ;* * ;* INT13 Version 1.0 10/21/86 * ;* * ;* Copyright 1986 Michael L. Brown * ;* Nicolet Instrument Corp * ;* 5225 Verona Rd * ;* Madison, WI 53711 * ;* (608) 273-5039 * ;* * ;* The user is hereby granted permission to use this program. * ;* User may not sell program. User may change and distribute this * ;* program, but may not charge for it. This program may be used * ;* in other programs, but may not charge extra for its inclusion. * ;* * ;* See the BASIC program DISKREAD.BAS for where to send corrections,* ;* enhancements, etc. * ;* * ;******************************************************************** PAGE ;******************************************************************** ;* * ;* An assembly language interface to the BASIC program DISKREAD, * ;* which allows the BASIC program to read absolute hard disk * ;* sectors. * ;* * ;* BASIC syntax is: * ;* * ;* CALL INT13(ES%,BX%,AL%,AH%,CL%,CH%,DL%,DH%) * ;* * ;* The registers work as follows: * ;* * ;* AL% Number of sectors to read/write * ;* AH% The DISKBIOS INT 13h operation: * ;* 00 Reset disk/diskette * ;* 01 Read status of last disk operation into AL% * ;* 02 Read sectors into memory * ;* 03 Write sectors into memory * ;* 04 Verify the sectors * ;* 05 Format the track * ;* 06 Format the track & set bad sector flags * ;* 07 Format the drive starting at track * ;* 08 Return the current drive parameters * ;* 09 Initialize drive pair characteristics * ;* INT 41 points to data block * ;* 0A Read long * ;* 0B Write long * ;* 0C Seek * ;* 0D Alternate disk reset (see DL) * ;* 0E Read sector buffer * ;* 0F Write sector buffer * ;* 10 Test drive ready * ;* 11 Recalibrate * ;* 12 Controller RAM diagnostics * ;* 13 Drive diagnostics * ;* 14 Controller internal diagnostics * ;* CL% Sector number (1-17, not checked) * ;* CH% Cylinder number (0-1023, not checked) * ;* DL% Drive number (80h-87h for disk, checked) * ;* DH% Head number (0-7, not checked) * ;* * ;* The cylinder (track) number is 10 bits, so the upper 2 bits * ;* of the cylinder number are placed in the top 2 bits of CL%. * ;* The remaining 8 bits are placed into CH%. Even tho CL% and CH% * ;* are 16 bit BASIC integers, to the 8088, CL and CH are 8 bits. * ;* * ;******************************************************************** PAGE ;******************************************************************** ;* * ;* When the INT13 program returns to BASIC, the following values * ;* are passed back: * ;* * ;* AH% The DISKBIOS INT 13h error numbers: * ;* 00 Operation OK * ;* 01 Bad command * ;* 02 Bad address mark * ;* 04 Record not found * ;* 05 Bad reset * ;* 07 Init failure * ;* 09 DMA boundary * ;* 0B Bad cylinder (track) * ;* 10 Bad ECC * ;* 11 Data corrected AL% contains burst length * ;* 20 Bad controller * ;* 40 Bad seek * ;* BB Undefined error * ;* FF Sense failure * ;* ES% Segment location of data * ;* BX% Offset location of data * ;* * ;* If disk parameters wanted: * ;* * ;* CL% Maximum useable sector & top 2 cylinder bits * ;* CH% Bottom 8 bits of cylinder number * ;* DL% Number of known drives attached * ;* DH% Maximum useable head number * ;* * ;* Assemble this code using the MASM assembler: * ;* * ;* MASM INT13,,INT13; * ;* * ;******************************************************************** PAGE PARMLST STRUC SAVE_BP DW ? ;Save contents of BP RET_OFF DW ? ;Return address of calling program RET_SEG DW ? REGDH DW ? ;Offset from DS of 8th argument REGDL DW ? ;Offset from DS of 7th argument REGCH DW ? ;Offset from DS of 6th argument REGCL DW ? ;Offset from DS of 5th argument REGAH DW ? ;Offset from DS of 4th argument REGAL DW ? ;Offset from DS of 3rd argument REGBX DW ? ;Offset from DS of 2nd argument REGES DW ? ;Offset from DS of 1st argument PARMLST ENDS PARM_SIZE EQU REGES - REGDH + TYPE REGES CODE SEGMENT BYTE PUBLIC 'CODE' ASSUME CS:CODE,DS:CODE BUFFER DB 512 DUP(0) ;Set aside area for disk data INT13 PROC FAR PUBLIC INT13 PUSH BP ;Save contents of BP MOV BP,SP ;Set addressability to params PUSH DS ;Save BASIC DS and ES values PUSH ES MOV SI,[BP].REGAL MOV AL,[SI] ;Number of sectors to read MOV SI,[BP].REGAH MOV AH,[SI] ;Function to perform MOV SI,[BP].REGCL MOV CL,[SI] ;Sector number MOV SI,[BP].REGCH MOV CH,[SI] ;Cylinder number MOV SI,[BP].REGDL MOV DL,[SI] ;Drive number MOV SI,[BP].REGDH MOV DH,[SI] ;Head number PUSH CS POP ES ;Set up segment address of buffer MOV BX,OFFSET BUFFER ;Offset of the address of buffer ; ; Save the ES and BX values for the BASIC program ; MOV SI,[BP].REGES MOV [SI],ES ;Save segment of buffer MOV SI,[BP].REGBX MOV [SI],BX ;Save offset of buffer ; ; At this point do the interrupt to get the disk data ; INT 13H ; ; Now we pass the info back to the program ; MOV SI,[BP].REGAL MOV [SI],AL ;Save AL MOV SI,[BP].REGAH MOV [SI],AH ;Save AH MOV SI,[BP].REGCL MOV [SI],CL ;Save CL MOV SI,[BP].REGCH MOV [SI],CH ;Save CH MOV SI,[BP].REGDL MOV [SI],DL ;Save DL MOV SI,[BP].REGDH MOV [SI],DH ;Save DH ; ; Clean up and return to BASIC program ; POP ES POP DS POP BP ;Clean up stack RET PARM_SIZE ;Restore the stack INT13 ENDP CODE ENDS END -- ihnp4------\ |------------------------| harvard-\ \ | terminus: | Mr. Video seismo!uwvax!nicmad!brown | The clearing house for | rutgers-/ / | rec.arts.drwho | decvax------/ |------------------------| terminus-----/
d757@sphinx.UUCP (01/15/87)
Don't Panic! (Clever how I got that in isn't it?). O.k. your problem is not
an uncommon one, as I have worked alot with PC hard drive crashes.
The first thing you should do is use the IBM diganostics disk that comes
with your PC_DOS manual. Use it to check if your hard drive has spots
(bad sectors) or its actually your controller card taht has problems.
Often controller cards may seem to work with certain hard drives and then
crash for no apparent reason. A fast solution might be to try replacing
the controller card with another one that you know that works. For those
taht don't know a controller card is attached by a ribbon cable to the hard
drive from one of the internal slots it if fairly easy to remove.
Another solution might be to check you dip switch settings (located inside
your machine, and notouriosly difficult to flip) to see if your machine
is setup to read 1 floppy and 1 hard drive.
I hope this is useful info to all.
--
"...nothing kills that does not know ye."
-Meg Davis, `The Elf Glade'
UUCP: ihnp4!gargoyle!larry Department of Mathematics@UofC
ihnp4!gargoyle!sphinx!d757 Computation Center@UofC