Path: utzoo!utgpu!water!watmath!clyde!att!ucbvax!hplabs!pyramid!cbmvax!daveh
From: daveh@cbmvax.UUCP (Dave Haynie)
Newsgroups: comp.sys.amiga
Subject: Re: CMI 68000 2x
Message-ID: <4603@cbmvax.UUCP>
Date: 30 Aug 88 20:36:25 GMT
References: <3372@crash.cts.com>
Organization: Commodore Technology, West Chester, PA
Lines: 45

in article <3372@crash.cts.com>, billium@pro-charlotte.cts.com (Bill Blanke) says:

> I was flipping through a magazine and saw an ad for CMI's processor
> accelerator. Its supposed to double the clock speed of the Amigas
> processor from 7.12 to 14.3 MHz. I've got a few questions about it.

> (2) How compatible is it with Amiga software. I remember someone
>     was saying how it was incompatible with dongles. Thats no problem
>     for me though since none of my software is dongled.

So far, the X-CAD dongle has proven to be sensitive to CPU speed.  The SuperBase
dongle isn't.  I haven't used any others myself.

> (3) Does the 2x speed increase affect games. I guess what I'm asking
>     is if Amiga games are timer based (wait 1 second and then do this)
>     or processor cycle based (execute these instructions as fast as
>     you can, then do this-I would have to deal with an arkanoids ball
>     flighing around twice as fast as normal!). If all are timer based
>     (hopefully) does this mean sometimes sluggish games (like Obliterator)
>     would perk up and move more smoothly, but still remain at their
>     current speed?

There are a few exceptions, but most Amiga games are synced to the video
display rate.  If you're using the Copper for anything, this probably falls
out automatically, for the most part.  

The other thing to consider is that Commodore-Amiga doesn't support software
that's CPU speed dependent.  You should be able to run your 68040 at 60MHz and
still expect everything to work A-OK.  Even Commodore-Amiga has had a speed
related bug or two show up, but we fix them.  So should any other software
vendors.

>     If they are cycle based is there a way to revert back to 7.12 Mhz,
>     preferably through a hardware switch?

I would expect it to be pretty difficult, and wouldn't recommend it.  The
easiest thing they could do in this respect, at least in an A2000 CPU
slot, would be to let the A2000's 68000 back on under program control.  I
use fast 68020s almost all the time now, and have run into very few problems
with the software I use (admittedly, very few games).

-- 
Dave Haynie  "The 32 Bit 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!"