PC/Atari 800KB disk images wanted

[mark_k]

I'm doing some testing of mfm.device (from CrossDOS) with different disk formats.

I'd like to obtain an image file of an 800KB-format PC/DOS disk. That would have 10 sectors/track instead of the normal 9 which a 720KB disk has. [I haven't been able to get CrossDOS to write a disk in that format in WinUAE. But it may well be able to read 800KB disks.]

The image file needs to be low-level and usable in WinUAE, so SuperCard .scp, CT raw or IPF.

If you feel like helping out and:
- Have access to an old PC with real/native floppy drive or an Atari ST
- Can use e.g. fdformat under MS-DOS to format a disk to 800KB, then image it. Or in Linux there's fdformat. fdformat in FreeBSD too. (Same name as the MS-DOS program but unrelated apart from performing a similar function.)
- Have suitable hardware to create a low-level image of the disk. 68020+ Amiga will work for the CT raw tool, or SuperCard Pro or Kryoflux.

An image of a 1600KB high density disk would be nice to have too. Again fdformat should be able to create such disks. Also some old SNES game copiers could format disks to 1600KB...

[Cylon]

You could use a DraCo for this instead, i believe. they have similar floppy drives. There was a thread over on a1k.org about that.

found it.
http://www.a1k.org/forum/showpost.ph...2&postcount=19

[demolition]

What about 1581 formatted disks for C64? They are also 800kB afaik.

Edit: Otherwise I do have a DOS machine with a proper floppy drive to my right and a Kryoflux to my left, so I could try to make both those images.. I think I even have fdformat on the DOS machine already.

[mark_k]

I think the 1581 format physically has 10 512-byte sectors per track. Whether or not the format is identical to an 800KB disk made by fdformat, I don't know. But it would be interesting to see whether mfm.device can recognise a 1581 disk.

[demolition]

I put three Kryoflux dumps in the zone, one of a blank 1581 formatted DD disk and using FDFORMAT (DOS version), an 800k DD and a 1600k HD floppy.

[mark_k]

Thanks very much for that! In case anyone else cares about this I used the KryoFlux DTC program to convert them to "CT raw" format (usable in WinUAE), uploaded to The Zone.

I very quickly checked the Blank-800k (PC format) image, and CrossDOS does recognise it.

Would you be able to upload another example image, created after filling the disk with some random files and dirs? I want to check that CrossDOS can handle it, i.e. that the files/dirs all read correctly.

Edit: I couldn't get CrossDOS (in WinUAE) to recognise the Blank-1600k image. Not sure whether that's a problem with WinUAE (maybe it assumes a CT raw image is a DD, not HD, disk?), or the SPS DLL, or CrossDOS/mfm.device. Or whether I just used the wrong options when running DTC to create the Blank-1600k.ctr image.

[demolition]

Originally Posted by mark_k

Would you be able to upload another example image, created after filling the disk with some random files and dirs? I want to check that CrossDOS can handle it, i.e. that the files/dirs all read correctly.

Edit: I couldn't get CrossDOS (in WinUAE) to recognise the Blank-1600k image. Not sure whether that's a problem with WinUAE (maybe it assumes a CT raw image is a DD, not HD, disk?), or the SPS DLL, or CrossDOS/mfm.device. Or whether I just used the wrong options when running DTC to create the Blank-1600k.ctr image.

I filled the 800k disk with files and folders and uploaded a dump to the Zone.
To format the 1600k disk, I used the -F16 option on FDFORMAT.

[mark_k]

Thanks again. It may be that CT raw format doesn't support HD disks, hence why I couldn't (yet) get the 1600K one working in WinUAE.

Some notes about 800KB disks:

• Even if your PC0 mount file has BlocksPerTrack=9 as for normal 720KB disks, CrossDOS can automatically detect the 800KB disk format, providing there is a DOS BPB(?) on the disk. If the 800KB disk were to contain (say) all zero bytes it wouldn't automatically detect the format. [Perhaps that's why it doesn't detect the 1581-format disk?]
• Say you want to copy an 800KB disk from DF0: to DF1:. Then you'd use a command like DiskCopy FROM PC0: TO PC1:
  But if you're using the normal/usual CrossDOS mount file for PC1: which has BlocksPerTrack=9, DiskCopy will refuse to do that because the geometries of source and dest won't match (even if the disk in DF1: is completely blank/unrecorded).
  
  By changing my PC1 mount file to have BlocksPerTrack=10 I managed to get DiskCopy to work. mfm.device has an (undocumented?) command for setting the disk format. It might be possible to write a program which uses that, to set 10 secs/track format before running DiskCopy to work around that issue.