Path: utzoo!attcan!uunet!vtserf!creatures!davism
From: davism@creatures.cs.vt.edu (Mat Davis)
Newsgroups: comp.sys.mac.hardware
Subject: Re: IIfx SCSI termination question
Message-ID: <486@creatures.cs.vt.edu>
Date: 11 Jul 90 17:49:09 GMT
References: <2155@esquire.UUCP> <42859@apple.Apple.COM>
Sender: usenet@creatures.cs.vt.edu
Reply-To: davism@vtopus.cs.vt.edu (Mat Davis)
Organization: Virginia Tech Computer Science, Blacksburg, VA
Lines: 27

In article <42859@apple.Apple.COM> blob@Apple.COM (Brian Bechtel) writes:
>
>The basics of SCSI termination are:
> * One terminator at the beginning of the chain
> * One terminator at the end of the chain
> * No terminators anywhere else.
>
>--Brian Bechtel		blob@apple.com		"My opinions, not Apple's"

But the manuals that came with a CMS drive state that you *shouldn't* use
termination on a two-drive chain *if* the cable is less that two feet long.
From what I've seen/heard about SCSI termination and some of the problems I've
had, I'm about to decide that you just have to experiment with different 
setups to get everything "just right".  

And while I'm at it, is there any software out there that can help diagnose
SCSI problems?  Right now I'm helping someone who's getting lots of SCSI
error messages from A/UX, and unless the external Apple 80SC or the Apple
tape drive is internally terminated, I *know* that it follows the rules above.
Yet we're still getting "SCSI Protocol Error", "SCSI Sense Error", and lots
of retries on the system.  BTW, the setup is:  IIci w/ 80M <-> External
Apple 80SC <-> Rodime 210e (term. removed) <-> Apple tape drive, and only the
tape drive has a terminator on it.

	Mat Davis
	Virginia Tech Computer Science Dept.
	(davism@vtopus)