From: orville%weyrich@uunet.uu.net (Orville R. Weyrich)
Subject: Re: Adaptec AHA-1542B and large SCSI questions
Reply-To: uunet.uu.net!weyrich!orville
Organization: Weyrich Computer Consulting
Date: Mon, 21 Dec 92 02:32:48 GMT

In article <1992Dec14.234840.2630@mksol.dseg.ti.com> mccall@mksol.dseg.ti.com (fred j mccall 575-3539) writes:
>In <1992Dec12.174722.407@weyrich.UUCP> orville%weyrich@uunet.uu.net (Orville R. Weyrich) writes:
>
>>I tried to use the Adaptec BBS and couldn't get through, so maybe the
>>net can help....
>
>>I got an Adaptec AHA-1542B controller and want to use it with OS/2 2.0
>>and a large SCSI disk. 

Specifically, a Maxtor P1-17S 1.5 Gig Panther.

>>My question is this: I have heard that SCSI disks larger than 1 Gb may
>>not work properly without BIOS upgrades or special drivers. Is this true for
>>OS/2? 

>I don't know if this is a problem for OS/2 or not, but if it is there
>is no fix for it.  The Adaptec PROM upgrade is for DOS ONLY.  The
>drivers for OS/2 make assumptions about the head/platter translation
>that the Adaptec controller is doing that would break if you updated
>the PROMs.

Talk about being between a rock and a hard spot!

I have been banging my head against a brick wall for the past two days trying
to get the Adaptec 1542B and the Maxtor P1-17S to work together.

What I have been trying to do is to set up boot manager for DOS 5.0,
Xenix, OS/2 2.0, and OS/2 beta. I wanted to keep my two MFM drives as well as
the new Maxtor SCSI drive. With one MFM drive installed and using the
FD controller on the MFM WD-clone controller, and with the FD controller on
the Adaptec SCSI drive disabled, I was able to get the OS/2 FDISK on the
installation program to partition both the MFM and SCSI drive to use the
disk manager (putting DOS and Xenix partions on my MFM drive and OS/2
partitions on the SCSI drive).

The first problem is that I lost 33% of my SCSI drive -- FDISK only sees
the first 1 Gig of the 1.5 Gig formatted capacity. 

Some folks on the net told me that OS/2 would be able to deal with larger
drives using device drivers built into OS/2. Were they mistaken or do they
have a trick I don't know about?

That is an annoyance but not a show-stopper. If OS/2 can only handle 1 Gig,
then I have 3 weeks on my no-questions-asked return allowance on the Maxtor,
and I can trade it down to a 1 Gig Fujitsu and get back some money.

Much more serious is the next problem that arose: when I tried to continue
with the install, the HPFS format stage failed as follows: Everything starts
out prety much as I expect, but the drive light only flickers on periodically.
As the formatting progresses, the duty-cycle of the light gradually changes
from mostly off to constantly on, and drive seek noises diminish in frequency
to nothing. Eight hours later, the drive still hasn't finished formatting a 
100 M primary partition.  This is reminiscent of a problem with the original
GA that appeared with one of my RLL systems, but was not present in the
first public beta code and which could be corrected by replacing the 
IBM506.ADD driver. Unfortunately, my attempts to install the beta version
had the same result. Is this a known problem and is there a new driver that
I should be using?

If I disable both of my MFM drives, then the install seems to work [I'm
on disk 4 of the GA version now]. But while this convinces me that the 
problem is not with my SCSI controller or SCSI drive, it is not a satifactory
situation for several reasons.

First of all, I need a non-SCSI partition to install Xenix on, and I want
to be able to boot DOS and 3 different versions of OS/2, which I can't do
with only a single SCSI drive.

Does anyone know how I can get my 1.5 Gig SCSI to co-exist with my two MFM
drives? BTW -- the MFM drives and controller have been cheerfully running 
the GA version of OS/2 ever since I got my 1.3 upgrade from IBM.

Help gratefully accepted,

orville

--------------------------------------           ******************************
Orville R. Weyrich, Jr.                           Weyrich Computer Consulting
Certified Data Processor                         POB 5782, Scottsdale, AZ 85261
Certified Systems Professional                        Voice: (602) 391-0821
Internet: orville%weyrich@uunet.uu.net                Fax:   (602) 661-0660
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