Path: utzoo!utgpu!watmath!att!tut.cis.ohio-state.edu!ucbvax!pasteur!ames!sun-barr!newstop!sun!kilowatt!raz
From: raz%kilowatt@Sun.COM (Steve -Raz- Berry)
Newsgroups: comp.sys.amiga.tech
Subject: Re: DTACK* or not to DTACK*, that is my question...
Message-ID: <120525@sun.Eng.Sun.COM>
Date: 10 Aug 89 01:06:50 GMT
References: <119697@sun.Eng.Sun.COM> <7563@cbmvax.UUCP>
Sender: news@sun.Eng.Sun.COM
Reply-To: raz@sun.UUCP (Steve -Raz- Berry)
Organization: Sun Microsystems, Mountain View
Lines: 40

In article <7563@cbmvax.UUCP> daveh@cbmvax.UUCP (Dave Haynie) writes:
>in article <119697@sun.Eng.Sun.COM>, raz%kilowatt@Sun.COM (Steve -Raz- Berry) says:
>> Hmm, I wonder how many people are going to figure out what I am tring
>> to build here? ;-)

>Well, it sounds like you're interested in the normal way of building a 68020
>or 68030 CPU interface for an A2000 type machine; far as I know, everyone
>does AVEC in much the same way.  It still doesn't make your 8520 interrupts
>fast, since they get vectored to a table that's in Chip memory unless you
>use the VPA register, which apparently isn't supported in 1.3, or use some
>MMU tricks.

Not exactly. Right now my system has a boring old 68K in it. I want to
make the *whole* machine go faster, not just this one part of the protocal.

>-- 
>Dave Haynie Commodore-Amiga (Systems Engineering) "The Crew That Never Rests"
>           Be careful what you wish for -- you just might get it

I wish for a free A2630 w/4meg ram ;-)

Thanks for the response. But since I have your attention, might I
impose on you for some more information?

Right now I have a way of disabling the 68K on the 2000's motherboard,
but I would be very interested in hearing a brief description from
you on the particular timing involved. The way I am approaching it now
is to wait for the Ami to come out of reset before I issue CBR*.

Also if you have any thoughts that you would care to share on any
particular signals to watch out for, I'd be mighty interested. As
George said, I keep getting knocked back to square one, (lately on the
clk high to FC valid timing - why oh why is it different than address
valid to AS* asserted???) and I'd like to eliminate as much of that as
possible.

---
Steve -Raz- Berry     Disclaimer: It wasn't me! I was volatilizing my esters.
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