Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!rpi!nisc.nyser.net!rodan!amichiel
From: amichiel@rodan.acs.syr.edu (Michielsen)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Formatting 1.2 Meg disks to 360K question
Keywords: floppy formatting
Message-ID: <1700@rodan.acs.syr.edu>
Date: 9 Jan 90 14:53:03 GMT
References: <3226@ucrmath.UCR.EDU> <7715@nigel.udel.EDU>
Reply-To: amichiel@rodan.acs.syr.edu (Michielsen)
Organization: Syracuse University, Syracuse, NY
Lines: 15

>In article <3226@ucrmath.UCR.EDU> lulu@ucrmath.UUCP (david lu) writes:
>=>I just tried to format some 1.2 Meg, high density disks in my
>=>360K drive (as 360K), and I got the following error message:
>=>	Invalid media or Track 0 bad - disk unusable

If you hold a real 1.2 MB disk up to the light and look at it at about a 30
or 45 degree angle, you should be able to see a ring. In the read/write window
at the outside edge of the floppy disk media. It's about .1 inch wide or so.
That 'window' is what causes dos to reject the disk for formatting.  If it
weren't there it would be possible for 360K drive to corupt the disk with an
attempted format.  In some 1.2 drives it also is used to select the drive
density initially.  When I have a disk I'm not sure of I just look for that
edge window & know instantly that it is a 1.2 MB disk.

al