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From: erick@CSUFresno.EDU (Eric Keisler)
Newsgroups: comp.sys.amiga
Subject: Re: 2091 Interface
Message-ID: <1990Oct30.195356.29263@CSUFresno.EDU>
Date: 30 Oct 90 19:53:56 GMT
References: <5357@crash.cts.com>
Reply-To: erick@zimmer.CSUFresno.EDU (Eric Keisler)
Organization: California State University, Fresno
Lines: 53

In article <5357@crash.cts.com> denny@pnet01.cts.com (Dennis Anderson) writes:
>I bought a 2000HD in March and a friend of mine bought a 590 to go with her
>500 at about the same time. We both are getting very good use of our systems
>but have run into a problem. My friend got ahold of a 20 meg SCSI drive and
>power supply. We cannot get the 2091 or the 590 to recognize this drive. The
>drive works fine on anouther friends 1000 using a Supra controller. When
>asking around for help we were told by SEVERAL Amiga dealers that the Roms in
>both the 2091 and 590 are not able to handle MORE THAN ONE SCSI DRIVE. Is this
>true??? 
> ...
> ...
>                                               Dennis Anderson
Well, from my experience, it isn't true.  I got my A2500/30 back in feb.  Last
week I hooked a 120mb Rodime drive to the external SCSI port of my 2091.  After
some work with the 2091 HDToolBox utility, I got everything setup just fine. As
a matter of fact, I've since used the Rodime SCSI drive to load software onto
a dozen or so Amiga 2500/30's (with 2091/quantum combos) in one of the 
computing labs here that I support. 

Some configuration notes and gotchas:

Since my drive was not of the default drive types in HDToolbox, I had to
go into HDToolBox, and use "Change Drive Type".  Then I selected
"Define New Drive Type" and clicked on "Read Configuration From Drive".  
HDToolBox had no problem getting the drive config info from the drive.  At
this point, be sure to set "Supports Reselection?" to "NO".  This is because
there is a bug (2091, ROM, or driver, I don't know which) that surfaces when
you have two (or more) drives talking on the scsi bus with 'reselection'
enabled.  I ran into this bug early-on when trying to copy one disk to another.
The 2091 and drives went into a lock-up condition.  Resetting the reselection
param via HDToolbox eliminated the problem.

To me, it looks like the "rumour" that the 2091 can't handle multiple SCSI
units is bunk.  Keep in mind that there are many ways you can shoot yourself
in the foot when interfacing multiple SCSI systems:

    Have you terminated the the bus?  (termintors installed on last device)
    Did you set the SCSI ID's for each unit correctly?
    Right cables?
    Are all the SCSI devices compatible with each other (talk the same SCSI?)
    Do *all* the software config params check-out? (i.e.: read the 2091 manual)

Hope this helps...

---
Eric Keisler, University Computer Services, CSU Fresno

erick@zimmer.ucs.csufresno.edu
erick@csufres.csufresno.edu