Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!usc!jarthur!nntp-server.caltech.edu!toddpw
From: toddpw@nntp-server.caltech.edu (Todd P. Whitesel)
Newsgroups: comp.sys.apple2
Subject: Re: Multi SCSI card system..
Message-ID: <1991Mar11.045531.3866@nntp-server.caltech.edu>
Date: 11 Mar 91 04:55:31 GMT
References: <15420@smoke.brl.mil>
Organization: California Institute of Technology, Pasadena
Lines: 19

gwyn@smoke.brl.mil (Doug Gwyn) writes:

>Why would one WANT to remove the bus terminating resistors?

So you can get more than 2 of them on a bus together. A properly terminated
SCSI bus has terminators on each end, and nowhere in between. With 2 DMA SCSI's
that means you have 1 computer on each end of the bus and all the devices in
between them with internal termination removed and no external terminators.
Try to add more DMA SCSI's and you will run into problems because of the extra
termination.

>Lack of proper termination was one of the main problems with
>the previous (non-DMA) Apple SCSI card.

External terminators fixed that. Apple should have included one free with the
Rev. C SCSI, but it doesn't really matter now.

Todd Whitesel
toddpw @ tybalt.caltech.edu