Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!samsung!zaphod.mps.ohio-state.edu!tut.cis.ohio-state.edu!pt.cs.cmu.edu!andrew.cmu.edu!br0w+ From: br0w+@andrew.cmu.edu (Bruno W. Repetto) Newsgroups: comp.sys.ibm.pc Subject: Re: What does "Probable Non-DOS disk" mean? Message-ID: Date: 8 Dec 89 02:39:50 GMT References: <1989Dec7.123115.13255@aucs.uucp> Distribution: na Organization: Graduate School of Industrial Administration, Carnegie Mellon, Pittsburgh, PA Lines: 47 In-Reply-To: <1989Dec7.123115.13255@aucs.uucp> >From: peter@aucs.uucp (Peter Steele) >Subject: What does "Probable Non-DOS disk" mean? >Date: 7 Dec 89 12:31:15 GMT > >I went to do a chkdsk/f the other day and it reported that drive C >was a "probable non-DOS disk". It gave me the option of continuing >and I did and everything worked fine. What causes this error and >can it be removed. The machine is running DOS 3.3. No partitions >are set up (it's a 20 meg disk). Any info would be appreciated. >Thanks! > > >-- >Peter Steele, Microcomputer Applications Analyst >Acadia University, Wolfville, NS, Canada B0P1X0 (902)542-2201x121 >UUCP: {uunet|watmath|utai|garfield}!cs.dal.ca!aucs!Peter >BITNET: Peter@Acadia Internet: Peter@AcadiaU.CA This means that you got garbage in the first 2 bytes of your FAT table. You should have a F8 FF sequence to indicate that it is a regular MS/PC-DOS partition. (It doesn't matter that the whole hard disk is dedicated to DOS as one physical drive; it is still one partition that covers the entire disk.) You can fix this by editting the FAT table with a binary editor (the Norton Utilities can help) and changing the first two bytes. This takes care of the annoying message from chkdsk, but leaves one wondering about what caused the error in the first place, and also worrying whether you are changing the FAT bytes correctly... In summary, not for the faint of heart. Backup first! So that's my $0.02. Bruno. Bruno Wiener Repetto Department of Operations Research Graduate School of Industrial Administration (GSIA) Carnegie-Mellon University Schenley Park Pittsburgh, PA 15213 GSIA Room 8b, x8730 [(412)CMU-8730] br0w+@andrew.cmu.edu