bobmon@iuvax.cs.indiana.edu (RAMontante) (09/11/90)
vsarkela@csc.fi <1990Sep11.144431.1@csc.fi> : | Does anyone know the diskette parameters? Interrupt 1Eh is actually | a pointer to those parameters, which are needed when formatting a | diskette. Yes, I know about fdformat PD program, which has source | code also in the packed file. Point is, it works only with 360 kB | diskettes. There is something wrong with those parameters (11 bytes). Not true --- as of version 1.20, which I have, it happily mucks around with my 720KB, 3.5" drive, and the documentation discusses 1.44M and 1.2M diskettes (I can't try those formats). This is the "fdformat" by Christoph Hochstaetter of Marburg, Germany. (I can't easily make an "a" with two dots over it, so I've substituted "ae". That might not be the best substitution; my apologies to Christoph.)
mitchell (Bill Mitchell) (09/11/90)
In article <1990Sep11.144431.1@csc.fi> vsarkela@csc.fi writes: > > > Does anyone know the diskette parameters? Interrupt 1Eh is actually > a pointer to those parameters, which are needed when formatting a > diskette. The following information was extracted from a shareware tech ref I got some time ago. I've found the reference very useful but have lost the sourcing info. It says it is Copyright Dave Williams. If Dave is listening, perhaps he can post sourcing info for the whole thing. Int 1e (0000:0078) points to a table used by BIOS. Default table location is f000:efc7. The table contains 11 bytes of data. 00: 4 bit step rate, 4 bit head unload time 01: 7 bit head load time, 1 bit DMA flag 02: 54.9254 ms counts of motor-off delay time (36-38 typical) 03: sector size code 00 128 bytes 01 256 bytes 03 512 bytes 03 1024 bytes 04: Last sector on track (8 or 9 typical) 05: Intersector gap on read/write (42 typical) 06: data length for DMA transfers (42 typical) 07: gap length between sectors for format (0xf6 typical) 09: head settle time in ms (15 to 25 typical) 0a: motor start time in 0.125 sec intravals (2-4 typical) ----------------------------------------- And the following was extracted from a smaller tech ref I got from a BBS. This was compiled by Information Modes, P.O. Box F, Denton TX 762602, (817) 387-3339: ORG 0efc7h ;address in IBM rom DISK_BASE label byte db 11001111B ;CF= SRT-C Unload=0f db 2 ;02= HD LOAD =1, MODE=DMA db 25 ;25= delay till motor off (ticks) db 2 ;02= 512 bytes/sector db 8 ;08= EOT, # sectors/track db 02ah ;2a= gap lenght db 0ffh ;ff= DTL db 050h ;50= gap for format db 0f6h ;fill byte for format db 25 ;head settle time in ms db 4 ;motor start time in 1/8 sec
vsarkela@csc.fi (09/11/90)
Does anyone know the diskette parameters? Interrupt 1Eh is actually
a pointer to those parameters, which are needed when formatting a
diskette. Yes, I know about fdformat PD program, which has source
code also in the packed file. Point is, it works only with 360 kB
diskettes. There is something wrong with those parameters (11 bytes).
Vesa Sarkela Keskuslaboratorio Oy
vsarkela@opmvax.csc.fi Finnish Pulp & Paper Research InstitutePA163514@tecmtyvm.mty.itesm.mx (09/15/90)
Vesa Sarkela You must review, interrupt 21h, service 1Ch Here is the information, GET FAT Information for drive *Interrupt 21h, service 1ch) Registers on entry AH: 1Ch DL: Drive code (A=0, B=1 etc) Registers on return AL : Sectors per cluster BX : Offset address of FAT ID byte CX : Bytes per sector DX : Clusters per disk DS : Segment address of FAT ID byte Memory affected: None The FAT ID byte to which DS:BX points indicates the type of disk in use Actually, this byte indicates only how the disk was formatted. Refer to next table for more information. Value Disk Characteristics F0 Not identifiable F8 Fixed disk F9 Double sided, 15 sectors/track F9 Double sided, 9 sectors/track(720 Kb) FC Single sided, 9sectros/track FD Double sided, 9 sectors/track (360 Kb) FE Single sided, 8 sectors/track FF Double sided, 8 sectors/track This could be enough, but if not send me a e-mail Juan Manuel Gonzalez Nava Informatic Research Center ITESM Monterrey Mexico Bitnet PA163514@TECMTYVM.MTY.ITESM.MX Chao. and god look. There is a new country. Mexico