Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!cbmvax!daveh
From: daveh@cbmvax.commodore.com (Dave Haynie)
Newsgroups: comp.arch
Subject: Re: the future of busses (and Futurebus)
Message-ID: <17215@cbmvax.commodore.com>
Date: 8 Jan 91 06:02:20 GMT
References: <13180@ganymede.inmos.co.uk>
Reply-To: daveh@cbmvax.commodore.com (Dave Haynie)
Organization: Commodore, West Chester, PA
Lines: 25

In article <13180@ganymede.inmos.co.uk> davidb@inmos.co.uk (David Boreham) writes:
> shri@ncst.ernet.in (H.Shrikumar) writes:
>> aglew@crhc.uiuc.edu (Andy Glew) writes:
>>   I was under the (evidently wrong) impression that VME-64 uses those pins!

>Can't remember where the other bit comes from, but anyway, this means
>that during the data-transfer cycles of a BLT operation, it is possible
>to move 64-bits at a time, rather than the 32-bits possible with basic VMEbus.

Which goes to demonstrate the principle that just about any non-multiplexed
N-Bit wide bus is just a multiplexed N*2-Bit wide bus that hasn't been enhanced
yet.  VME64 is the latest example.  We did this with the 16 bit Amiga bus, IBM
at least specified the same idea with the non-multiplexed 32 bit MCA bus that
mutates into a multiplexed 64 bit bus, and I'm sure there are others (is that
how STD32 works?).  I guess MIT and TI leapfrogged the inevitable by stating out 
multiplexed in the first place with NuBus :-)...

>David Boreham, INMOS Limited | mail(uk): davidb@inmos.co.uk or ukc!inmos!davidb


-- 
Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests"
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