Problems reading older disk on newer drive

From: Paul Koning <pkoning_at_equallogic.com>
Date: Sun Dec 19 11:30:25 2004

>>>>> "Nico" == Nico de Jong <nico_at_farumdata.dk> writes:

 Nico> From: "Vintage Computer Festival" <vcf_at_siconic.com> Subject:
 Nico> Problems reading older disk on newer drive


>> I'm trying to read a disk an old double-density PC formatted disk
>> on a high-density drive. I can read the directory and certain
>> small files just fine, but any files that are larger than a few
>> sectors (or perhaps that span a track) return "Sector Not Found"
>> errors. This is under DOS 6.22. Is there a way to get DOS to
>> recognize that this is a double-density disk and to perform
>> whatever internal magic is necessary to read the disk properly?
>> Or is this an issue of hardware?

 Nico> Normally, there would not be a problem, supposing it is a 360K
 Nico> disk (I guess you are talking about 5.25" disks). What I
 Nico> _have_ seen, is that "modern" BIOS'es have problems / cannot
 Nico> read disks formatted as 320K. Back in the old days, 5.25" disks
 Nico> came in even more flavours, like 160K (I've never seen an 80K
 Nico> 5.25" though)

 Nico> I cant find my DOS manuals right now, but there used to be a
 Nico> function in DEVICE in CONFIG.SYS where you could do some rather
 Nico> clever things with regard to disk formats.

In Linux you can get the floppy driver to read all sorts of weird
formats; check out the docs. (I forgot where the details are.) For
example, I found that I could have Linux read and write DEC RX50
format floppies, which are 5.25 inch floppies with 10 sectors (not the
usual 9) per track.

      paul
Received on Sun Dec 19 2004 - 11:30:25 GMT