Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!pacific.mps.ohio-state.edu!linac!att!rutgers!cbmvax!drysdale
From: drysdale@cbmvax.commodore.com (Scott Drysdale)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: A3000 and Bridgeboard
Message-ID: <20303@cbmvax.commodore.com>
Date: 2 Apr 91 22:52:15 GMT
References: <1991Mar25.192928.20577@isis.cs.du.edu> <1991Apr1.102906.1@vf.jsc.nasa.gov>
Reply-To: drysdale@cbmvax.commodore.com (Scott Drysdale)
Distribution: usa
Organization: Commodore, West Chester, PA
Lines: 57

In article <1991Apr1.102906.1@vf.jsc.nasa.gov> kent@vf.jsc.nasa.gov writes:
>> I have heard rumors that the Bridgeboard from Commodore/Amiga (that works with
>> A2x00 series computers) won't work with the A3000.
>> 
>> 1)	Is this true?
>> 2)	Is there a fix in the future??
>
>It does work with the 3000.  I have installed one on a 3000 running wb 2.0.
>However, the pcdisk command on the amiga side does not work all the time. I
>saw a post that said you have to disable the memory cache when issuing the 
>pcdisk command.  After the command is issured you can turn it back on.

!!!!NO!!!!

you must do the cache disabling *before binddrivers* and it must remain
disabled until you turn the power off.

the problem:
	on a system with a data cache (68030 and up) running ks/wb 2.x,
	the data cache is enabled by the operating system.  under 1.3, the
	data cache is never enabled, so no problem.
	the bridgeboard (and possibly some other cards) is a large chunk
	of shared memory.  if either the 80x86 or the 680x0 caches anything
	in bridgeboard address space, things won't work.

the solution:
	you must disable data caching of bridgeboard address space when
	running ks/wb 2.x on a 68030 or better system.

method 1:
	insert the line:
	CPU NODATACACHE
	before the binddrivers command in your startup-sequence.  this will
	disable *all* data caching, potentially slowing your system down
	slightly.  everyone with 2.x should have the CPU command.

method 2:
	insert the line:
	ENFORCER QUIET
	before the binddrivers command in your startup-sequence.  this will
	disable data caching only for bridgeboard address space.  other
	"normal" RAM in your system will be cached as usual.  not everyone
	has ENFORCER, and only recent (past few months) versions know
	bridgeboards.

>-Mike

  --Scotty
(i really ought to figure out a way to put the above in my .signature)

-- 
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Scott Drysdale           Software Engineer
Commodore Amiga Inc.     UUCP {allegra|burdvax|rutgers|ihnp4}!cbmvax!drysdale
		         PHONE - yes.
"Have you hugged your hog today?"
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