Path: utzoo!attcan!uunet!samsung!gem.mps.ohio-state.edu!apple!netcom!stratus!cloud9!jjmhome!m2c!wpi!jhallen
From: jhallen@wpi.wpi.edu (Joseph H Allen)
Newsgroups: comp.sys.ibm.pc,wpi.sys.ibm
Subject: Re: Hard Drive format failure
Keywords: hard drive format failure
Message-ID: <5641@wpi.wpi.edu>
Date: 16 Nov 89 15:34:54 GMT
References: <5352@wpi.wpi.edu>
Reply-To: jhallen@wpi.wpi.edu (Joseph H Allen)
Organization: Worcester Polytechnic Institute, Worcester, MA. USA
Lines: 35

In article <5352@wpi.wpi.edu> vertical@wpi.wpi.edu (Anthony D Putorti) writes:

>code: 02h no addr mark c0,h1,s:18

This means:  cylinder 0, head 1, sector 18.  An address mark is an
"out-of-band" byte that indicates the beginning of the track (it's a byte
which is always completely unique from any data bytes so it never gets
confused with them).

The low level format built into the controller is probably stupid, that is, it
probably doesn't check for errors.  I'm guessing that the first track (or
maybe second- depends if 'h1' is the first or second head) is damaged- just as
your other format program said.  I'm pretty sure that this track must be
flawless for DOS to format.

First, try this:  use fdisk to move the DOS partition to a higher cylinder. 
If this doesn't work, then the track fdisk uses is damaged and you're really
screwed.

Second try this:  Most controllers have a way of formatting bad tracks so that
they use alternate tracks.  So, try to find a better low level format program.
Spinwrite is supposed to be very good, maybe it knows how to do this. 

If all else fails:  Since the error occured on sector 18, I'd guess that it's
the disk itself that is bad, not any of the electronics.  So if you are really
daring, you might try to move the track zero sensor in a little.  On
miniscibes, I think it is a little optical sensor in which a wing attached to
the stepper motor rotor breaks the light.  There is probably an adjustment
screw with some kind of epoxy poured into it (to prevent tampering?) which you
have to move.  The exact setting of this isn't critical.  It does have to be
stable, however.

Oh, if it turns out that the sensor is in the bubble (in the sealed part of
the disk), don't tamper with it.  If you break the bubble, you will void the
warranty, and the disk will become infinitely flakey.