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From: Fletcher@cup.portal.com (fletcher sullivan segall)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: 68030+68040 on A3000: is it possible?
Message-ID: <41966@cup.portal.com>
Date: 3 May 91 17:08:00 GMT
References: <24561@well.sf.ca.us>
Distribution: na
Organization: The Portal System (TM)
Lines: 39

>
>   At the back of AmigaWorld's April '91 issue, in the section devoted
>to rumors, speculation, etc., there was an intrigueing idea proposed:
>Designing an 040 board that would allow the 030/882 to continue functioning,
>essentially as coprocessors to the 040. They stated that all that would be
>needed to implement this would be to "tweak" the system software so that
>it would recognize both chips were aboard.

Sounds like an interesting idea.  Unfortunately most structure locking
is done with Disable/Enable, or Forbid/Permit rather than with system
semaphores, so the whole system would frequently revert to mono-processing.
But I doubt that the Rom/Kernel will be modified to run multi-processing.
No doubt OS/9 will step forward quickly to fill the gap to some degree, 
and I imagine a variety of hacks will come out to allow certain system
functions to run on the '030 as a coprocessor.  This might include 
blitter emulation, or various device support routines.

>
>A wonderful idea! though the 030/882 combination would be grossly slower
>than the 040, it seems to me that on our multitasking system, they could be
>used to manage the more mundane system tasks, while the real "gut-busters" 
>would simply be sliced to the 040 exclusively.
>
>Unfortunately, as i understand it the Fast Slot on the A3000 motherboard
>is a bus master slot - it disables the 030. 

Your information is incorrect.  The coprocessor slot on the A3000 fully
supports using both processors simultaneously (this is one of the changes
from the A2000).  
>
>Would a crafty hardware firm be able to create a workaround? is it feasible?
>is it worth the trouble? - it seems a waste to throw out the 7.5 mips the
>A3000 pumps out...27+ Mips would be screaming....
>
I think the 68030 at 25MHz is only about 4.25 (V2,1) MIPS.

-ss

Fletcher@cup.portal.com