Path: utzoo!attcan!uunet!ispi!jbayer
From: jbayer@ispi.UUCP (Jonathan Bayer)
Newsgroups: comp.unix.xenix
Subject: SCO 2 Harddisk controllers
Message-ID: <1181@ispi.UUCP>
Date: 7 Oct 89 12:51:56 GMT
Organization: Intelligent Software Products, Inc.
Lines: 47


Karl Denninger posted:

>(lockup problems)
>
>In article <1176@ispi.UUCP> jbayer@ispi.UUCP (Jonathan Bayer) writes:
>>I did essentially the same thing, although I modified a 1006V-MM1 for the 
>>alternate interrupt and address.  I tried it with a Seagate 4051 (40 meg drive)
>>and had the identical problem.  I think that there is something in the
>
>If you have a Feature 5 level card, make sure you have it jumpered for
>NON-LATCHED mode.  If not, you need to do yet another mod.
>
>The F5 cards WILL lock up like this if you have them running in latched
>mode.  We went back to a Feature 3 card, and the problem disappeared.  I


Problem solved.  It turns out to be a two-fold problem.  First, a bit of
background:

	This is running on an Everex Step/25, with all the options
turned on to get the last bit of speed out of it.  This includes the bus
speed being at 12.5 Mhz.  Also, I am using a WD1006V-MM1 controller card
jumpered for the alternate address, and slightly modified to get the
alternate interrupt.


First I had to make the change as described above to put it into
NON-LATCHED mode.  I checked it out, and the problem was almost gone. 
This time it successfully passed all of my tests, except for doing a
thorough bad-track scan of the third drive, when it locked up :-(   I
was almost ready to give up in disgust, when I decided to try and slow
down the speed of the i/o buss from 12.5 Mhz to 8.33 Mhz.  Voila, it
passes all the tests now without locking up.  My guess is that in
addition to the controller glitch it also cannot handle buss speeds of
greater than 8-9 Mhz :-(

Anyway, I am not going to depend on this third drive for about a week of
use, just to make sure.  My thanks to Karl for his note about the
feature level/latched mode on the card.


JB
-- 
Jonathan Bayer		Intelligent Software Products, Inc.
(201) 245-5922		500 Oakwood Ave.
jbayer@ispi.COM		Roselle Park, NJ   07204