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. UUCP: sun!kilowatt!raz ARPA: raz%kilowatt.EBay@sun.com KILOWATT: sun!kilowatt!archive-server archive-server%kilowatt.EBay@sun.com