19 Dec
2004
19 Dec
'04
11:30 a.m.
>>>> "Nico" == Nico de Jong
<nico(a)farumdata.dk> writes:
Nico> From: "Vintage Computer Festival" <vcf(a)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