Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!cica!tut.cis.ohio-state.edu!ucbvax!agate!shelby!lindy!news From: BL.JPL@forsythe.stanford.edu (Jonathan Lavigne) Newsgroups: comp.sys.ibm.pc Subject: Re: CHKDSK: Probable Non-DOS disk, Continue? (Y/N) Message-ID: <4880@lindy.Stanford.EDU> Date: 25 Sep 89 05:19:45 GMT Distribution: usa Lines: 28 In article <26495@iuvax.cs.indiana.edu>, bobmon@iuvax.cs.indiana.edu (RAMontante) writes: >-<26474@iuvax.cs.indiana.edu> beckman@iuvax.cs.indiana.edu (Peter Beckman) : >- >- When I run chkdsk on my C:, DOS 3.30, I get the question shown above. >- It started happening recently. What has changed? > >This happened to me recently, although all the data was fine. Various >people pointed me to the first byte of the FAT, which contains an ID >value. It turns out that the ID byte had gotten scrambled somehow; this >mattered to chkdsk, but not to most programs. > >If that's the problem, you can use a sector editor to patch things back >up. A fixed disk should have a value of 0xF8; different floppies have >different ID values. I too just had this problem. An epidemic? I was told that the proper value for the first two bytes of the FAT is "F8 FF", and that there are two copies of the FAT that need to be changed. When I looked at the two copies using PC-Tools, both read "F7 FF", so I guess that's where the problem lay. My difficulties were complicated by the fact that DOS refused to set the proper FILES value from my CONFIG.SYS file when I booted using my hard disk. Reformatting the disk cleared up both problems. Jonathan Lavigne BL.JPL@RLG.STANFORD.EDU Research Libraries Group Stanford University