Path: utzoo!attcan!telly!eci386!clewis
From: clewis@eci386.uucp (Chris Lewis)
Newsgroups: unix-pc.general
Subject: Re: 3B1 Hard Disk Woes (Plea for HELP!)
Keywords: disk failure,diagnostics
Message-ID: <1989Jul28.145300.17237@eci386.uucp>
Date: 28 Jul 89 14:53:00 GMT
References: <8569@cbnews.ATT.COM> <1989Jul26.174524.21833@eci386.uucp> <850@flatline.UUCP>
Reply-To: clewis@eci386.UUCP (Chris Lewis)
Distribution: na
Organization: R. H. Lathwell Associates: Elegant Communications, Inc.
Lines: 39

In article <850@flatline.UUCP> erict@flatline.UUCP (J. Eric Townsend) writes:

>According to an AT&T tech who came out and replaced the HD in
>my 3b1 (while it was under warranty), this is something that could
>be fixed from floppy-unix, if AT&T had bothered to ship a program
>that could do the super-low level format needed to test the hard drive.
>This is where I start to lose understanding of the subject, so
>I only *think* I'm correct.

You're not.  He may have been simply mistaken, or trying to make sure that
you only buy drives from AT&T because "only we can format 'em".
[Only a possiblity, I see no evidence of this with the AT&T people I
deal with]

Proof?  Simple: almost every single ST506 controller uses a slightly
different pattern of bits for the physical representation of sectors
headers and trailers.  We do hardware maintenance on a host of machines,
and I can assure you that when you take a disk from another type of
machine and insert it in a 3b1, the formats are different, and the 
diagnostic floppy formatter *does* do low level formats.  (Otherwise,
I'd never get a new drive for my machine  ;-)

The "disk erase and file system preparation" program he was refering to
is UNIX "mkfs" and is the second stage of preparing a HD for UNIX.
(analogous to low level formatters and FDISK on DOS)

However, there are at least a few companies that do not provide low
level formatters for HD's, or other similar things like requiring
tape drivers to only accept a tape with a label that only the
machine's vendor can write.  So they can have a captive media market.

You can take some comfort that at least one of these companies (quite 
large at one point I may add) has gone belly up.  So did the company
that took 'em over.
-- 
Chris Lewis, R.H. Lathwell & Associates: Elegant Communications Inc.
UUCP: {uunet!mnetor, utcsri!utzoo}!lsuc!eci386!clewis
Phone: (416)-595-5425