Path: utzoo!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!emory!ogicse!sequent!uunet!cbmvax!daveh
From: daveh@cbmvax.commodore.com (Dave Haynie)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: 3000  16 Mhz  vs  25 Mhz
Message-ID: <19943@cbmvax.commodore.com>
Date: 18 Mar 91 18:19:18 GMT
References: <47475@nigel.ee.udel.edu> <1991Mar14.152303.26147@uokmax.ecn.uoknor.edu>
Reply-To: daveh@cbmvax.commodore.com (Dave Haynie)
Distribution: all
Organization: Commodore, West Chester, PA
Lines: 32

In article <1991Mar14.152303.26147@uokmax.ecn.uoknor.edu> rrmorris@uokmax.ecn.uoknor.edu (Rodney Raym Morrison) writes:
>Could someone give DETAILED differences between 16Mhz & 25Mhz on the 3000.

ONE MORE TIME...  The difference in these two systems is the clock speed of
the Motorola chips, 68881 in the 16MHz system vs. 68882 in the 25MHz system,
and the actual system clock provided for clocking everything else.  The 
Motorola chips in a 16MHz system can't be clocked at 25MHz, but the Amiga 
chips can.

>Specifically, I plan to get the 040 board very soon, and I don't want to spend
>the extra money on 25Mhz if it's not necessary.

That would depend on the design of the '040 board.

>  Like, can you just swap a crystal on the mother board (implying that
>verything is the same),  

No, you can't.  The Motorola chips in a 16MHz system can't be clocked at 25MHz.

>Does the 16Mhz limit the speed for the 040 board, etc..

Any Coprocessor Slot device can clock the A3000 chips at 25MHz, while leaving
the clock going to the Motorola chips at 16MHz.  It is up to the designer of
the Coprocessor Slot device to do this, or not.  

>thanks


-- 
Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests"
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	"What works for me might work for you"	-Jimmy Buffett