Path: utzoo!attcan!uunet!lll-winken!ames!mailrus!csd4.milw.wisc.edu!uxc!deimos!ksuvax1!kuhub.cc.ukans.edu!dougm
From: dougm@kuhub.cc.ukans.edu (Douglas Miller)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Bad sectors
Message-ID: <2819@kuhub.cc.ukans.edu>
Date: 10 Jan 89 23:17:58 GMT
Organization: University of Kansas Academic Computing Services
Lines: 20


  CHKDSK will not detect and set bad clusters (containing bad sectors).  It
is only capable of checking the starting cluster numbers in the directories
against the file allocation cluster chains for the various files.  On the
basis of that information it will tell you which chains are unconnected
or cross connected or have multiple references in the directories.  CHKDSK
will, incidentally, report any bad cluster marks it may have found while
analyzing the FAT.
  In order to set the bad sectors you must feed the information from the
bad sector map (usually attached to the disk in the form of a sticker)
provided by the manufacturer to a program designed to perform that function.
You may also do the calculations and the setting by hand (NU or
Debug).  The bad cluster mark is FF7 hex for 12-bit MSDOS FATs and FFF7
for the 16-bit variety.  As for DOS 4.0 and UNIX I cannot say.
  At any rate, I think there is a program called Disk Manager that will do
what you require.  Perhaps someone out there will be so kind as to provide
the correct information if I have been speaking from within my lower 
intestine.

--Another know-nothing opinion from the desk of D. Miller.