rzh@lll-lcc.UUCP (Roger Hanscom) (02/14/90)
Does anybody have the vital statistics on Kaypro 5.25" DSDD
floppies?? Things like sectors/trk, BSH, etc. I believe they
should be about 390K with 10, 512b sectors/track. I'm trying
to write a BIOS that will use the Kaypro format. What is the
interleave for this format??
roger rzh@lll-lcc.llnl.govrlb@cs.odu.edu (Robert L. Bailey) (02/15/90)
In article <2756@lll-lcc.UUCP> rzh@lll-lcc.UUCP (Roger Hanscom) writes: > >Does anybody have the vital statistics on Kaypro 5.25" DSDD >floppies?? Things like sectors/trk, BSH, etc. I believe they >should be about 390K with 10, 512b sectors/track. I'm trying >to write a BIOS that will use the Kaypro format. What is the >interleave for this format?? > Yes, the Kaypro DSDD format is as you described. I'm not absolutely sure about the interleave, but, here is some other info that you will need to create the disk parameter block & header: PARAMETER Hex Decimal Sectors/trk 28 40 Blk shift factor 04 4 Alloc Block Mask 0F 15 Extent Mask 01 1 Disk Size Max 00C2 194 Dir Max -1 007F 127 Alloc Mask 0 C0 192 Alloc Mask 1 00 0 Dir Check size 0020 32 Sys Trks Offset 0002 2 Hope this helps. Bob Bailey
dbraun@cadev5.intel.com (Doug Braun ~) (02/16/90)
In article <2756@lll-lcc.UUCP> rzh@lll-lcc.UUCP (Roger Hanscom) writes: > >Does anybody have the vital statistics on Kaypro 5.25" DSDD >floppies?? Things like sectors/trk, BSH, etc. I believe they >should be about 390K with 10, 512b sectors/track. I'm trying >to write a BIOS that will use the Kaypro format. What is the >interleave for this format?? > How is it that this format has 10 sectors per track, while IBM PCs have only 9 (and the old ones could only get 8 in)? I recently got a 5.25" floppy controller for my CP/M computer (which normally uses 8" SSSD), but it can only read 8 and 9 sectors per track. Does anyone know a resonably popular CP/M format that I could adopt, and thus interchange my 5" disks with somebody? I remain, etc., Doug Braun Intel Corp CAD 408 765-4279 / decwrl \ | hplabs | -| oliveb |- !intelca!mipos3!cadev4!dbraun | amd | \ qantel / or: dbraun@cadev4.intel.com
rlb@cs.odu.edu (Robert L. Bailey) (02/17/90)
In article <1647@mipos3.intel.com> dbraun@cadev5.UUCP (Doug Braun ~) writes: >In article <2756@lll-lcc.UUCP> rzh@lll-lcc.UUCP (Roger Hanscom) writes: >> >>Does anybody have the vital statistics on Kaypro 5.25" DSDD >>floppies?? Things like sectors/trk, BSH, etc. I believe they >>should be about 390K with 10, 512b sectors/track. I'm trying >>to write a BIOS that will use the Kaypro format. What is the >>interleave for this format?? >> > >How is it that this format has 10 sectors per track, while IBM PCs >have only 9 (and the old ones could only get 8 in)? > >I recently got a 5.25" floppy controller for my CP/M computer >(which normally uses 8" SSSD), but it can only read 8 and 9 sectors per >track. Does anyone know a resonably popular CP/M format that I could adopt, >and thus interchange my 5" disks with somebody? > The reason that IBM did not use 10 sectors/track is probably that they decided that it was pushing the capacity of the media too much. IBM is a very conservative bunch, don't ya know? The IBM hardware is perfectly capable of reading/writing 10 sectors/track. I know. I have a non-standard formatting program on my PC that DOES use 10 SPT. Most likely, your hardware is capable of handling 10 SPT. You just need an appropriate formatting program and new disk parameter tables in your BIOS. I have an old Xerox 820-1 that originally 8" only. I added a 5 1/4". Later, I got a new double density controller from Emerald Microware. This allowed me to add more drives and accomodate different disk formats as well. My configuration ended up as follows: 1 8" SSSD 1 5 1/4" SSDD 1 5 1/4" DSDD 1 5 1/4" DSQD (80 trk double density - but not like IBM 1.2M) These drives along with a program called UNIFORM allowed me to read/write just about any format that exists, including IBM 360K disks! My standard format that I used most of the time was the Kaypro 5 1/4" DSDD 390K. This is probably about as close to a "universal" CP/M format as you will find, because the Kaypro machines were very popular in their day. I believe that they were the top seller in the CP/M arena. In summary, if your controller is capable of reading/writing double density, then some new disk parameters in your BIOS should enable you to handle the Kaypro format. Check your controller chip. If its a Western Digital 17xx or 27xx, it should work (except for the 1771 which is SD only). The NEC 765 and others in that family are also capable (most PCs use one of these). Hope this helps. Bob Bailey
mlinar@eve.usc.edu (Mitch Mlinar) (02/17/90)
In article <1647@mipos3.intel.com> dbraun@cadev5.UUCP (Doug Braun ~) writes: > >How is it that this format has 10 sectors per track, while IBM PCs >have only 9 (and the old ones could only get 8 in)? > This is possible since a track on disk has lots of stuff around it for synchronization, etc. The actual number of bytes per track is fixed and dependent upon the method and disk size (FM/MFM, SD/DD). Kaypro "shortchanged" the synchronization header and intermediate headers so that an extra sector could be squeezed into it. Nine is possible even using the manufacturers recommended track format; IBM used eight originally because it simplified the BIOS logical to physical sector xlation.