Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!dali.cs.montana.edu!uakari.primate.wisc.edu!sdd.hp.com!elroy.jpl.nasa.gov!jarthur!ucivax!ucla-cs!ucla-seas!turing!plinio From: plinio@turing.seas.ucla.edu (Plinio Barbeito) Newsgroups: comp.sys.atari.st Subject: Re: Atari cpu evolution Keywords: Motorola 68040 Message-ID: <2318@lee.SEAS.UCLA.EDU> Date: 4 Apr 91 06:44:38 GMT References: <12229@uhccux.uhcc.Hawaii.Edu> Sender: news@SEAS.UCLA.EDU Organization: SEASnet, University of California, Los Angeles Lines: 105 In article <12229@uhccux.uhcc.Hawaii.Edu> kiki@uhunix1.uhcc.Hawaii.Edu writes: >[someone speculates about evolution of Atari TT models with Motorola 68040 cpu] A reasonable speculation, IMHO. And as long as we're talking about a 1993 time frame, it would also be fair to bring even the 68050 into the discussion. >I guess it would be safe to assume that Atari is considering the '040 cpu for >their next generation along the TT product line. But the microprocessor spec- >trum has shifted from the dominance of the 80x86 and 68000 families from Intel >and Motorola. One alternative is mentioned by the author of the following art- Not in terms of volume sold, you mean the ever-elusive claims of performance by chip manufacturers. >icle. And although he seems to disdain the specifications of the chip, I think >it might be of significance and worthy of serious consideration. > >-------------------------[start of article]------------------------------------ [...large portion deleted] > >Name When Price Technology MIPS >PgC7600 1/91 400 $ Bipolar 200 >PgC7610 2/92 40 $ CMOS 80 >PgC7620 1/93 100 $ Bipolar 250 >PgC7700 2/93 400 $ CMOS 1000 >PgC7710 4/93 200 $ Bipolar 2000 > >If you ask me: Too little, too late, no serious performance, no software. >Forget it. >------------------------------[end of article]--------------------------------- > >If the PgC series has the capability of adaptable microcode and CISC emulation, >then it would merit consideration by Atari as an alternative to the Motorola >68000 line. At the very least, it would offer Atari a little leverage against >Motorola's monopoly of the '030 and '040 market. At best, Atari would have a It would be more fair to call it a monopoly if Motorola's prices were unreasonable (like intel's). >computer that could run 80x86/68000/6502 etc. binary code, by loading the >proper microcode. Promising 80 MIPS by Feb. 1992 for $40 in (large volumes, I assume)? Sounds great, but it is just that -- a promise. Has intel ever made good on the promise that its i860 would run at 50MHz so that the 150 max MIPS figure hyped by the press could come to light? How fast does the chip run under normal conditions (i.e. with interrupt processing ON, using usual compiler output, using affordable (read slower) chips for memory)? Anyone want to take bets on whether intel's benchmarks had interrupts enabled, or ran the dhrystone benchmark from 80nsec memory? At least with a 68040, with its familiar instruction set, we know what kind of performance to expect by simply looking at the average number of instructions per cycle and the capacity of the cache. Other questions to be resolved: how efficiently would the processor emulate a 68000; is the microcode well geared to emulate its rich set of addressing modes and (small) irregularities? Would it have enough micromemory to do it? Can it address enough registers, or would it have to draft part of the cache for this role, inevitably slowing things down? How fast can it do a multiply or divide (it would have to do this very quickly in general purpose microcode to beat out an 040 with a built-in FPU with dedicated microcode)? We wouldn't know all of this until the machine and emulation software were implemented. That's a long way off. Also, a lot of fast cpus will be introduced in this year of 1991, so that 80 MIPS (whatever that means in real terms of performance) may not seem as fast by comparison in one year. And 1993? Well, in computer years, that's ages hence. By then, the 68050 may be a more familiar sight. It is difficult to speculate on numbers relating its performance with the information we have now, but...there was a recent announcement that Moto just built the largest, most dense chip yet (for the US Navy, too advanced for mortals like us to buy, with a good amount of space devoted just to nuclear-proofing redundancy), and one must begin to wonder what they're going to be able to do with their commercial products (that don't need to waste any space for redundancy) by 1993. >CISC emulation and multiprocessing capabilities. The pricing and performance >seem to be exceptional to me and are some of the qualities associated with >Clive Sinclair (and perhaps Atari), so that a Timex 200000K could soon be in >our hands? I'm all for power without price as much as the next guy, but my general feeling is that it's too soon to tell. As long as one can speculate all the way out to 1993, one can speculate about a lot of other things, many of them silly...like the Common Market banning American chips because the high frequencies might disrupt brain processes that control the ability of consumers to choose for themselves between labels stating "with hormones" or "without", or the Japanese opening their market to American rice due to a widespread boycott of Japanese submarine propellers :-P. When I see the TT040, or the PgC-ST at my dealer...or even at Toys-R-Us...I'll be convinced. Until then we can only make suggestions to Atari and hope that they'll listen. Right now we are having enough trouble getting them to put a 1.44 Meg drive into the TT...(by the way, TRH, your portable design is fine the way it is, IMHO). plin -- ----- ---- --- -- ------ ---- --- -- - - - plinio@seas.ucla.edu This page intentionally left blank so that it could contradict itself.