Newsgroups: comp.periphs.scsi
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!uunet!coplex!disk!corpane!herman
From: herman@corpane.uucp (Harry Herman)
Subject: Re: BIG problem with 1542B and Quantum disks
Message-ID: <1991May15.001511.4063@corpane.uucp>
Keywords: scsi quantum 1542b
Organization: Corpane Industries Inc.
References: <1991May9.002915.262@wyvern.uucp> <711@curly.appmag.com>
Date: Wed, 15 May 1991 00:15:11 GMT
Lines: 25

In <711@curly.appmag.com> pa@curly.appmag.com (Pierre Asselin) writes:

>Here goes nothing:  my own "internal" 105S came with terminating
>resistors.  Look for SIP's on the PC board just above the SCSI
>connector.  Try wiring one drive at an unterminated end of the bus.

>As long as I'm here, should I even *think* of removing the drive's
>terminating resistors?  I hate to fix something that ain't broke,
>but I'd like to do things right.  Tom will have to do something
>(maybe).  Is trading-in the drives his only option?

>--Pierre Asselin, R&D, Applied Magnetics Corp.  I speak for me.

As I understand the SCSI spec, only the electrical ends of the cable
are to be terminated.  Generally the controller is at one end of
the cable, and some drive is at the other end.  We have routinely
removed the terminators from all drives in between.  In one case
we purchased a drive that had its terminators SOLDERED IN PLACE.
So, I put that at the electrical end of the cable, but still set
the LUN jumper to be a higher unit number.  So, on that system, the
physical drive ordering is unit 2, unit 0 and unit 1 with the controller
after unit 1, and terminators in unit 2 and the controller.

				Harry Herman
				herman@corpane