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From: dslg0849@uxa.cso.uiuc.edu (Daniel S. Lewart)
Subject: Re: CHKDSK --> "Probable non-DOS disk."
Message-ID: <1991Apr11.161422.2870@ux1.cso.uiuc.edu>
Keywords: chkdsk disk DOS FAT
Sender: usenet@ux1.cso.uiuc.edu (News)
Organization: University of Illinois at Urbana
References: <1991Apr10.173621.26608@ux1.cso.uiuc.edu> <wu68Z4w164w@graphics.rent.com>
Date: Thu, 11 Apr 1991 16:14:22 GMT
Lines: 16

elund@graphics.rent.com (Eric W. Lund - Subop) writes:

> Something has partly trashed your FAT.  The first byte in the FAT should be
> hex F8.  The first byte is the "media descriptor byte", and F8 is for "fixed
> disks".  To stop the message, use a sector editor and change the first byte
> back to what it should be.  If your system is working fine now, then I
> wouldn't worry about it, but you should realize something has altered your
> FAT, and that's not a healthy thing for a program to do.  The FAT should
> never be touched except by programs such as FDISK or FORMAT.

I used Norton's NU to change the first FAT byte from AC to F8.  It worked!!!
Two other respondents indicated that PCTOOLS 6.0 Diskfix should also work.
Thanks, Eric!

Dan
d-lewart@uiuc.edu