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From: davest@tektronix.UUCP (Dave Stewart)
Newsgroups: net.unix-wizards
Subject: Re: 4.3 uda.c - warning
Message-ID: <8465@tektronix.UUCP>
Date: Mon, 25-Aug-86 12:24:20 EDT
Article-I.D.: tektroni.8465
Posted: Mon Aug 25 12:24:20 1986
Date-Received: Tue, 26-Aug-86 02:57:56 EDT
References: <409@hsi.UUCP>
Reply-To: davest@tektronix.UUCP (Dave Stewart)
Distribution: net
Organization: Tektronix, Inc., Beaverton, OR.
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	It is fairly standard practice in these parts to put a UDA-50 on
its own unibus.  DEC recommends putting a UDA-50 only with other DEC
hardware on a unibus, but we have found that even this can cause
problems.

	An interesting development of this is that the VAX 8650 we have
here at Tek has a unibus that is designed to have only a UDA-50 because
there are no slots for anything else!  (Actually, even this can be bent
since we got DEC to squeeze a DR11-B on this bus because of timing
problems with another device).  This strikes me as humorous: most
peripheral manufacturers design their equipment around CPU features.
Here poor DEC has to design their CPU around their peripherals!
Anyway, I degress.

	If you have more than one unibus, the good money is on moving
everything off of the bus that has the UDA-50.  Then you should not
need to worry about the burst rate or other device-bus contention
problems.  My apologies to DEC if I have oversimplified this or
overstated it.

-- 
David C. Stewart                          uucp:    tektronix!davest
Unix Systems Support Group                csnet:   davest@TEKTRONIX
Tektronix, Inc.                           phone:   (503) 627-5418