Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!samsung!munnari.oz.au!bruce!goanna!giaea!doug
From: doug@giaea.gi.oz (Douglas Thomson)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: Formatting a 1.44 MB disk to 720 kB - not so easy!
Message-ID: <1777@giaea.gi.oz>
Date: 20 May 91 00:42:27 GMT
References: <1991May16.220514.23423@ariel.unm.edu> <1991May18.123021.7256@topaz.ucq.edu.au>
Organization: Monash University College Gippsland, Churchill 3842, Victoria, AUSTRALIA.
Lines: 36

In article <1991May16.220514.23423@ariel.unm.edu>, ee5391aa@triton.unm.edu (Duke McMullan n5gax) writes:
> Just that...how?  For background, I have a 12MHz `286 box, which runs messdos
> 3.3 with 4dos.  Drive A: is a high-density 5.25" floppy; drive B: is a high-
> density 3.5" microfloppy.  Can this be done?  Am I staring right through the
> answer, which is sitting right there in the doc.s for all to see?

Under MS-DOS 3.3, the format option required to format a low density disk
in a high density drive is /n:9. The command would be:
    C:\>format b: /n:9

However, if you try this with a high density disk DOS responds with:
    Invalid media or Track 0 bad - disk unusable
    Format failure
[that nice high density disk just isn't good enough for low density work :-)]

To actually make it format, you must do two things: first, cover up the
high density hole on the disk so that the disk looks like a low density
disk, and second, use the /n:9 format option. When I do all this with a
high density disk I get:
    C:\>format b: /n:9
    Insert new diskette for drive B:
    and strike ENTER when ready

    Format complete

        730112 bytes total disk space
        730112 bytes available on disk

The exact results may of course vary from one version of DOS to another,
and from one BIOS to another. I am using MS-DOS Version 3.30 without
4DOS, and with an AMI 10/10/90 BIOS (all on a '386SX if it makes any
difference)...

Doug.
(doug@giaea.oz.au)
...!munnari!goanna!giaea!doug