I just picked up a set of Zenith MS-DOS 3.21360k disks.

Unfortunately Disk 1 has some surface damage and critically, the custom version of FORMAT.COM Version 3.29 (c) 1988 11562 bytes is corrupted. When I make a copy of the disk with Anadisk, it appears to work partially but hangs when attemting to run FORMAT /s.

I've checked the version on Winworld and it is slightly different - FORMAT.COM version 3.28, 17166 bytes.

If anyone can help with an image or a copy of the v3.29 file to re-create the disk I would be extremely grateful.


  • Is this the "Z-100 PC" (not "Z-100") version? We do have a copy of Microsoft MS-DOS 3.21 [Zenith Z100 PC] (5.25-360k) on Winworld.
  • edited July 9
    Already looked at this - 3.21 [Zenith Z100 PC] but thanks for the suggestion. Mine has country set to 44 in config.sys so I suspect it's a version for the British market.

    I guess I should make a dump of it to share, less the bad sectors.

  • But were the rest of the programs the same? If the format program has the same data and size, then it is probably identical.

    Can't really tell from a photo, but that disk doesn't look too bad. Try using a wet q-tip to clean the surface (do not use alcohol, that can make things worse)

    Do you have a kryoflux? That will dump as much readable bits of the bad sectors as possible. (If readable, that often includes sector CRC of a bad sector which is useful to verify that guesses at manual patching are correct).

    Otherwise, yes, make a dump with ImageDisk or Teledisk and let us take a look at it.
  • I'll do as side-by-side check of the files to see what the differences are. FORMAT.COM is definately different.

    The disk damage is actually worse than it looks in the photo, the disk coating has either been scratched or lifted away and there is a crater on there!

    Here is a dump using IMDISK plus copies of the readable files; also a list of defective sectors and affected files:

    I don't have a Kryoflux yet but I'm slowly convincing myself I should order one...
  • Update on this one - I made a further copy using a 1.2MB drive and this time only 2 sector errors affecting EXE2BIN.EXE (3056 bytes) and PRINT.COM (9379 bytes).
    EXE2BIN.EXE seems to be common to other releases but PRINT.COM looks like another Heath Zenith custom version.

    I'm hopeful I can turn this into an [OFFER] at some point.
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