From: bwhite@oucsace.cs.ohiou.edu (William E. White )
Newsgroups: comp.sys.att
Subject: 3B2 is now very dead.  help?  ideas?
Date: 1 Oct 92 03:41:40 GMT
Organization: O.U., Harvard on the Hocking, Berkeley in the Boondocks!

To those who helped my previous problems, thank you.  I managed to get
IDTOOLS so I could try and format my second hard drive.

Before I got a chance, however, the first hard drive died a horrible,
ugly death.  I'm not sure quite what happened except that I came down the
next morning and INIT was complaining that it couldn't do anything.  I
rebooted but the drive's sanity track was corrupt and it stopped there.

I tried to reformat (using IDTOOLS), but it wouldn't format; verify told
me that track 0 heads 5 thru 8 (the drive is a 72MB CDC) were bad (all
the sectors, 0 thru 17), track 1 heads 0 and 5 thru 8, track 2 heads
5 thru 8, and at this point I quit.

I then replaced this drive with a Seagate ST277R (yes I know it's RLL).
Since I didn't know what ID number to call it (and it couldn't read any
off the disk), I called it ID number "2" (HD10) and changed the number
of tracks and cylinders to match that of the disk.  The format went
just fine.

However, when I went to access it (with verify, or fixdisk, or whatever),
every OTHER disk access would fail with "GETPHYS: Could not initialize
disk 0".  Also, the sound of access was different; the times it failed
it sounded as if the disk drive was trying to re-initialize.  So I assumed
that was actually the case and fiddled with the jumper settings on the
ST-277R.

After changing the jumper settings on the back of the disk, I finally
found one that would stop this (of course, it was undocumented, but it
worked).  But wait, it gets worse.

I installed Unix again and rebooted.  Now, everything worked OK ... until
I let it sit for a few minutes after logging in.  Then, it gave me
the following errors:

---------
hard disk: cannot read sector 0 on drive 1
Disk Error Daemon: open of equipped disk 17/16 failed
WARNING: unreadable CRC hard disk error, maj/min = 17/16
	block # = 0
WARNING:
hard disk cannot access sector 0 head 0 cylinder 0 on drive 1
WARNING:
hard disk cannot read sector 0 on drive 1
Disk Error Daemon: open of equipped disk 17/16 failed
Disk Error Daemon: Disk maj=17 min=16: cannot access it
Disk Error Daemon: CRITICAL ERROR: physical description sector 0
	is bad on disk maj=17 min=16
	contact your service representative
Disk Error Daemon: CRITICAL ERROR: physical description sector 0
	is bad on disk maj=17 min=16
	contact your service representative
--------

This was the same set of error messages that appeared when my original
disk drive died.  (Reboot of Unix worked, but after a bit the same errors
returned.  I can reboot as often as I like, but the error messages always
happen, and once they do they keep happening sporadically until I reboot).

I ran DGMON for a good two hours (including a lot of hard disk interface
diagnostics) and it turned out OK.  I also talked to an AT&T service 
representative, who told me the following:
	- the "every other time fails" problem resulted from the ID number
	  not corresponding to the firmware's idea of how many tracks and
	  heads the drive had
	- there was no way (or rather, AT&T won't tell anyone how) to add new
	  drives to the firmware
    - I'll always have problems unless the firmware is sure of the drive
	  I'm using.


So I suppose now I have several questions ...

1. Relating to the CDC 72MB drive,
	a. Can I obtain replacement parts?  The circuitry on the drive seems
	   fine, it seems as if the sealed disk unit itself is bad.  
	b. If not, where does one find MFM drives these days, especially ones
	   that work in a 3B2-310?
	c. Anyone know how to tell the firmware about a new device (e.g., drive
	   with different # of tracks and heads)?
2. Relating to the problem in general, does this sound like a disk problem
	or a motherboard problem?


Thanks for your time, everyone who reads and/or replies; I'm losing my mind
over this system.


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