Path: utzoo!mnetor!uunet!cbmvax!daveh
From: daveh@cbmvax.UUCP (Dave Haynie)
Newsgroups: comp.sys.amiga
Subject: Re: 68000 speed up kits
Message-ID: <3292@cbmvax.UUCP>
Date: 10 Feb 88 06:09:24 GMT
References: <6861@agate.BERKELEY.EDU>
Distribution: na
Organization: Commodore Technology, West Chester, PA
Lines: 26

in article <6861@agate.BERKELEY.EDU>, spencer@eris (Randy Spencer) says:
> I don't really need to spend $250++ on the
> '020 chip when I could get a 16 MHz 68000 for $20.  And the board would
> be easier to build.  Just transfer all the lines up from the 68000
> socket, except the timing lines.  Only problem is that I am no
> hardware type.  I will build the thing if someone will tell me that 
> it will work, but I don't get the physics of it.

Well, first someone would have to find a reliable source of 16Mhz 68000s.
Once you've got that, you could build an accelerator board.  It would have to
slow down for Amiga bus access, otherwise it can run faster.  Now, that may
not buy you much.  If you can hook it up to 16MHz or whatever memory, you
could maybe go 1.5 times faster than the current Amiga, depending on how
much you talk to CHIP or slower expansion RAM.  The 68020 gets a speed win
if it's got 32 bit memory to talk to, which the 68000 certainly doesn't.  And
it wins because of it's instruction cache, which is always going to run at
your 16MHz or whatever, even if the instructions came from slower memory.

On the plus side, you've have much less hardware to build, since the 68000
already has a 68000 compatible interface.

> Randy Spencer      P.O. Box 4542   Berkeley  CA  94704        (415)222-7595 
-- 
Dave Haynie  "The B2000 Guy"     Commodore-Amiga  "The Crew That Never Rests"
   {ihnp4|uunet|rutgers}!cbmvax!daveh      PLINK: D-DAVE H     BIX: hazy
		"I can't relax, 'cause I'm a Boinger!"