Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!mips!spool.mu.edu!olivea!uunet!cbmvax!daveh
From: daveh@cbmvax.commodore.com (Dave Haynie)
Newsgroups: comp.sys.amiga.advocacy
Subject: Re:  The 68050 - end of the 680x0? (was Re: The Amiga's Future)
Message-ID: <22763@cbmvax.commodore.com>
Date: 28 Jun 91 06:02:54 GMT
References: <5216@orbit.cts.com>
Reply-To: daveh@cbmvax.commodore.com (Dave Haynie)
Organization: Commodore, West Chester, PA
Lines: 30

In article <5216@orbit.cts.com> chucks@pnet51.orb.mn.org (Erik Funkenbusch) writes:
>awessels@ccwf.cc.utexas.edu (Allen Wessels) writes:
>>In article <5171@orbit.cts.com> chucks@pnet51.orb.mn.org (Erik Funkenbusch) writes:

>>>year later, still a 16 Mhz machine) then FINALLY comes the IIci which is 25
>>>Mhz, the speed at which their machines SHOULD have been clocked for to begin
>>>with).  then comes the IIfx which uses a 50 Mhz 030 chip clocked at 40 Mhz(!)

There really is a 40MHz 68030, though the 50MHz came first.  The early '030
design only worked up to 33MHz; a design tweak resulted in 50MHz.  But, as
always, they don't get every chip made to pass at 50MHz, so they created the
40MHz part.  The 40MHz CPU-Cache/20MHz system bus make sense when you consider
the Mac's NuBus.  Since NuBus is a synchronous bus with a relatively slow
clock (10MHz), you'll die in synchronization delays if your CPU isn't in sync
with it (like Mac II, IIx, IIcx, and IIci).  The IIfx, more than likely, is
designed with a fully synchronous motherboard<->NuBus interface.

>>Really?  Were those 25Mhz chips being produced in the quantities Apple would
>>need?

25MHz '030s were sampled early in '88.  The A2500/20 came out in the fall of
'88, the A2500/30 in the fall of '89.  The first 25MHz A2630 was running in
prototype form at the Washington D.C. Amiga Developer's Conference in 1988. I
don't recall when the IIci first shipped.


-- 
Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests"
   {uunet|pyramid|rutgers}!cbmvax!daveh      PLINK: hazy     BIX: hazy
	"This is my mistake.  Let me make it good." -R.E.M.