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From: grr@cbmvax.UUCP (George Robbins)
Newsgroups: comp.sys.amiga
Subject: Re: 14.31818 MHz 68010 Upgrade
Message-ID: <2191@cbmvax.UUCP>
Date: Wed, 31-Dec-69 18:59:59 EDT
Article-I.D.: cbmvax.2191
Posted: Wed Dec 31 18:59:59 1969
Date-Received: Tue, 11-Aug-87 02:25:14 EDT
References: <19965@ucbvax.BERKELEY.EDU> <204@dana.UUCP> <942@omepd> <20038@ucbvax.BERKELEY.EDU> <2695@hoptoad.uucp> <20043@ucbvax.BERKELEY.EDU>
Reply-To: grr@cbmvax.UUCP (George Robbins)
Distribution: world
Organization: Commodore Technology, West Chester, PA
Lines: 32

In article <20043@ucbvax.BERKELEY.EDU> robinson@renoir.Berkeley.EDU.UUCP (Michael Robinson) writes:
> In article <2695@hoptoad.uucp> farren@hoptoad.UUCP (Mike Farren) writes:
> >In article robinson@renoir.Berkeley.EDU.UUCP (Michael Robinson) writes:
> >[regarding a double speed 68000/10 add-on]
> 
> Yes, yes, yes, I know.  I hate to keep bothering everyone with this, but the
> purpose of my original posting was to try and determine whether there would
> be a speed-up even with fast RAM.  If a memory expansion does not use 
> demand/contention refresh, but rather assumes that the processor can safely
> be locked out of every other cycle, then there will be almost no speed 
> increase in fast RAM either.  I still haven't heard anything from anyone
> affiliated with the various manufacturers of memory expansions.  Am I to 
> assume from the silence that every manufacturer of memory expansions for
> the Amiga is cheating on the refresh?  Perry?

You could refrain from calling it cheating or otherwise implying that there
is something wrong with designing memory such that it works nicely with the
the Amiga as it comes from the box.  In the marjority of cases it is better
to blow alternate cyccles for hidden refresh than to use a contention
refresh scheme that causes wait states as do some of the external expansion
devices.

If I didn't mention this previously, Commodore A2000 2MB and 8MB boards use
hidden refresh.  I don't know that any of the expansion boards that will
run double speed, although you should send mail to Perry, his hardware
designer is a clever person with performance on his mind.  I suspect though,
that if you want fast:fast:fast RAM, you have to put it on your board...

-- 
George Robbins - now working for,	uucp: {ihnp4|seismo|rutgers}!cbmvax!grr
but no way officially representing	arpa: cbmvax!grr@seismo.css.GOV
Commodore, Engineering Department	fone: 215-431-9255 (only by moonlite)