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From: johnt@hammer.TEK.COM (John Theus)
Newsgroups: net.micro.mac,net.micro.68k
Subject: Re: What's Nu with VME for Mac?
Message-ID: <2652@hammer.TEK.COM>
Date: Thu, 30-Oct-86 15:03:11 EST
Article-I.D.: hammer.2652
Posted: Thu Oct 30 15:03:11 1986
Date-Received: Mon, 3-Nov-86 21:29:40 EST
References: <842@gould9.UUCP> <1240@hoptoad.uucp>
Reply-To: johnt@hammer.UUCP (John Theus)
Organization: Tektronix, Inc., Wilsonville, OR
Lines: 36
Keywords: NuBus, VME, slotted Mac
Xref: mnetor net.micro.mac:7776 net.micro.68k:1412

In article <1240@hoptoad.uucp> gnu@hoptoad.uucp (John Gilmore) writes:
>
>The Nu bus is not a standard, and has been adopted by few companies.
>The VMEbus is, and seems to be the "Multibus of the '80s" as far as
>peripheral card availability.  By the way, it is a "VMEbus", and the
>cards that go in it are "VMEbus cards", not "VME cards".  You don't
>talk about plugging Uni cards into your Unibus, do you?

And NuBus (IEEE 1196; IEEE 896 is Futurebus) is not Nu bus.

I don't know your definition of standard, but as far as the IEEE is
concerned neither is a standard, and both are awaiting approval by the
Computer Society's Microprocessor Standards Committee (MSC).  Multibus II
is also at this stage, while Futurebus has been approved by the MSC.

If your definition of standard is based on the number of companies using
the bus, then yes, VMEbus is much more widely used.

If your definition of standard is based on the number of options and
incompatabilities allowed by a specification, then NuBus wins hands down.
With NuBus you don't have the problems of differing address and data widths,
and a free for all in the use of the address space.

NuBus was developed at MIT.  Western Digital went into the business of
building boards for MIT and the NuMachine, and for LMI.  TI bought this
business from Western Digital, and uses NuBus in their AI machines.
The principal players at WD, and then TI, now work at Corollary.
George White of Corollary is the chairman of the IEEE 1196 committee.

NuBus, along with Multibus II and Futurebus, can all be classified as
modern, full feature buses, while VMEbus is a wide Multibus with an improved
electrical environment.

John Theus
Futurebus Parallel Protocol Coordinator
Tektronix, Inc.