Newsgroups: comp.sys.ibm.pc.hardware
Path: utzoo!utgpu!watserv1!maytag!watstat.waterloo.edu!dmurdoch
From: dmurdoch@watstat.waterloo.edu (Duncan Murdoch)
Subject: Where's the track and head count on an XT disk?
Message-ID: <1990Sep18.025816.26168@maytag.waterloo.edu>
Sender: daemon@maytag.waterloo.edu (Admin)
Organization: University of Waterloo
Date: Tue, 18 Sep 90 02:58:16 GMT
Lines: 25


A friend of mine recently misplaced a lot of data on a big disk, because
a hardware conflict somehow messed up the track and head count that his
Western Digital XT controller wants to use.  I've also got a Western Digital
controller.  I don't know the model number, but the BIOS has a 07/15/86 
copyright and the low-level formatter is WX2 revision 1.0S.

I've been looking through my BIOS trying to figure out where the track and
head count are stored, hoping that we'll be able to patch up my friend's
disk.  (Western Digital tech support suggested reformatting the disk, but
he's got stuff there he doesn't want to lose.)  

Someone told my friend that XT controllers have an unaddressable
track before track 0, and that's where they keep things.  I can't tell
if that's true or not, but I do see it storing something in the first
sector, after the partition table.

Does anyone know for sure where this kind of controller keeps the setup
information?  More to the point, do you know how to patch it without doing
a reformat?

Any help would be greatly appreciated.

Duncan Murdoch
dmurdoch@watstat.waterloo.edu