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From: keithl@loop.uucp (Keith Lofstrom;;;628-3645)
Newsgroups: comp.periphs.scsi
Subject: Re: Wren IV controller problem
Message-ID: <1991Apr14.223631.17353@loop.uucp>
Date: 14 Apr 91 22:36:31 GMT
Article-I.D.: loop.1991Apr14.223631.17353
References: <1991Apr12.165103.23099@ee.rochester.edu>
Organization: Launch Loop, Portland OR
Lines: 30

In article <1991Apr12.165103.23099@ee.rochester.edu>
kaser@ee.rochester.edu (Bob Kaser) writes:
>
>I have recently installed an SPARCstation SLC SunOS 4.1.1, replacing a 
>SUN 3/50, using a CDC Wren IV disk.  We now see scsi error messages coming
>from the esp0 scsi controller.

This may not be relevant, but ...

I recently put a Falcon 760 Mbyte external drive on a SPARC IPC.  The 
cable supplied was 1 meter long.  The IPC already had an external tape
and CD-ROM drive.  With all that cabling, the drive gave errors.  Removing
the other two peripherals made the external drive work without errors.

I custom ordered a half meter cable, and it worked with all the peripherals.
Falcon now sells the shorter cable for SPARC class machines.

Modern SCSI hosts push the cabling to full speed, and many cabling setups
that used to work won't go fast enough - the magic buzzwords are impedance
mismatch, stub reflection, dispersive dielectric, and so on.  It's 
surprising things work as well as they do.  If you run into problems that
seem to be software, but won't go away, take a tip from an old electron
wrangler and make your cables shorter.

Good luck,
Keith
-- 
Keith Lofstrom  keithl@loop.uucp ...!sun!nosun!loop!keithl (503)628-3645
KLIC --- Keith Lofstrom Integrated Circuits --- "Your Ideas in Silicon"
Design Contracting in Bipolar and CMOS - Analog, Digital, and Power ICs