Path: utzoo!attcan!uunet!lll-winken!lll-lcc!unisoft!gethen!farren From: farren@gethen.UUCP (Michael J. Farren) Newsgroups: comp.sys.ibm.pc Subject: Re: GATHER and say NO to MCA! Message-ID: <978@gethen.UUCP> Date: 30 Jun 88 09:56:14 GMT References: <42900016@uicsrd.csrd.uiuc.edu> <257@octopus.UUCP> Reply-To: farren@gethen.UUCP (Michael J. Farren) Organization: There's Unix there in Oakland Lines: 36 In article <257@octopus.UUCP> pete@octopus.UUCP (Pete Holzmann) writes: [Before I start, one question: Mr. Holzmann, have you ever designed a high-speed digital bus? I have. Now, on with the show...] >1) MCA is cleaner, newer, nicer, etc etc: > All true, all irrelevant. On a bus, what works is what counts! This is true. However, what is NOT true is the claim that the AT bus "works". No 32-bit data/address path, insufficient DMA and interrupt support, insufficient attention to loading and timing details essential to truly high-speed operation, and a god-awful electrical emissions characteristic. I don't blame IBM one bit for getting rid of the damned thing. >3) MCA handles multiple CPU's. > So does the AT bus. A kludge, true, Not a kludge. A disaster. True coprocessing is damn near impossible. >My conclusion: the clone-makers need to pick a 32-bit AT bus extension > standard. There is little engineering reason (right now) to go to the > MCA. Unless you count greater reliability, better support for advanced architecture, better support for I/O, greater noise resistance, less emissions problems (therefore easier to get FCC type approval, therefore cheaper), etc.... Not that I think that MCA is the BEST bus around, mind, but anyone who claims that the AT bus is sufficient is talking through his engineering hat. -- Michael J. Farren | "INVESTIGATE your point of view, don't just {ucbvax, uunet, hoptoad}! | dogmatize it! Reflect on it and re-evaluate unisoft!gethen!farren | it. You may want to change your mind someday." gethen!farren@lll-winken.llnl.gov ----- Tom Reingold, from alt.flame