Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!purdue!ames!sun-barr!male!pitstop!sun!kilowatt!raz From: raz@kilowatt.uucp (Raz- Berry) Newsgroups: comp.sys.amiga.tech Subject: Re: A FLAME, was (80860 as a math processor) Summary: Hmm, this was a surprize. Keywords: Super Sexton belching Message-ID: <33763@kilowatt.uucp> Date: 1 May 89 16:35:37 GMT References: <15147@gryphon.COM> <33756@kilowatt.uucp> <15248@gryphon.COM> Reply-To: raz@sun.UUCP (Steve -Raz- Berry) Distribution: usa Organization: Sun Microsystems, Inc. - Mtn View, CA Lines: 175 In article <15248@gryphon.COM> richard@gryphon.COM (Richard Sexton) writes: )you all know how I hate to flame, but JESUS, STEVE, did you read anything )I wrote ? Sure, it was a little confused, but I read it. )))The stupid thing is memory mapped. You write the operands into )))memory addresses, then give it an operation, then poll it for )))completion. Some co-processor. ))Not a true co-processor if you ask me, ok so it fits the description... ))but it's a kluge. )No Steve. A co-processor would execute math instructions out of the )680x0 instruction stream. This thing acts more like a peripheral chip )in that you have to write operands and what operation to perform )to the chip; poll for completion, then read the result. But I said that. Essentially a co-processor just means 'in conjunction' with. The COPPER in the Amiga has to be fed instructions just like a peripheral chip. You build a Copper list in memory and then tell the copper sequencer (by slamming it's code address into a dedicated register) where to start executing it's next instruction stream. You can do the same kind of thing with the Weitek part, if it's smart enough. But by your definition, the Amiga Copper is misnamed. Gee, I guess that means Commodore will have to rewrite all their hardware manuals. But basicly I was agreeing with you, why get nasty? )))Some performence data: )) )))Linpack - single precision 8 MFLOPS ))) double 6 MFLOPS )))Whenstone Single precision 2.0 MWhets (is that what he said ? Mwhets ?) ))) Double 1.2 )) ))Did it say how this was set up? What I mean is, is it a 680x0 peripheral ))or is it running it's own code memory (probably). If it needs it's own ))special memory, like cache, then you might as well build a seperate board ))and do it up as black box math server. If you are going to go to that ))much trouble, might as well go with the '860 and get REAL speed. ))I guess I define co-processor as a transparent hardware accelerator. ))If you can hook it up to the main processor, with minimum amount of ) )Thats ``Hassle''. I hate seeing good hippie words misspelt. The rest )I don't care about. Well, I guess I should just curl up and die eh? I feel like I am tress- passing in some tigers lair, and if I don't agree with what the idiot tiger thinks, or I say things a little differently... tiger bait. I was looking for information as to how they got their performance #'s. Good answer Rich. ))hassel, and have it run out of processor memory space, then it's a ))co-processor. My definition. Weitek would probably disagree. )Steve, get a grip. The 6888x is a true co-processor. Of course No shit. I was talking about your fabled Weitek peice of crap. I *know* it is not a "true" co-processor. I *know* it is a polled device. My point was if you can't just plug'n play with the 68881 without significant speed advantages, then it is not worth the silicon it's cut from. )your definition, while, uhh, *unique* is not the one generally )held by the rest of the world. This Weitek thing is a peripheral Ahh, the world speaks. )math processor, which thay are *thinking* about making into a single )chip if enough people call them and say it's a great idea, )we'll take 100,000. But it'll still be another peripheral chipm )not something that executes 680x0 floating point instructions. )But I said that. No, you didn't. )))How do these figures compare with '881/2 and 860 ? ))I have no clue. I looked in the 881 manual and couldn't find the performance ))figures. )Thats nice Steve, but I don't believe you. I'm not going to believe )it until EVERYBODY in this group posts that they dont know. Gee, I'm hurt. Try looking in an applications note dummy, I can't do everything for you. )))Some interesting stuff about this part - it doesnt exist. It seems )))Weitek has a nice math chip, the 3116 or something like that. They )))sell a daughtorboard that has some glue logic and this chip )))for use with the 386. What they have for the 68000 is a board )))that uses the 3116 and some glue. If all they have is a board, then who's machine does it plug into? Not an Amiga I bet. Or is it a daughter board like the 386 counterpart? Try to be a little clearer richard, not everyone is an ESPer like you. ))Is it compatable with the 881 instruction set? If not, why bother? You'ld ))have to write your own compiler for it. YECHH. Unless it does sin(x)/cos(y) ))in two cycles... )No Steve, for the third time, it doeesnt execute 680x0 floating )point instructions. It's a f***ing peripheral chip. You don't have )to write your own compiler for it, you talk to it through memory )mapped addresses. Many of us have found it possible to do this )without re-writing a compiler. And no it doesnt do sin(x)/cos(y) )in two cycles. It doesn even do a divide in two cycles. I asked If you don't have compiler support, this severly limits the number of people who would be interested in this kluge. Except you Richard, I'm sure you will be perfectly happy doing POKE valx, 2104948. Wait, does it being a peripheral chip imply instruction set incompatability? Interesting design concept. Just because you memory map something doesn't mean it can't execute instructions compatible with the native coprocessor. It doesn't mean you can't microprogram it like the TI graphics chip, although I admit for a math chip this would be unusual. )if this thing was fast enough to not need polling for completion, )like the old 4Mhz Z-80/9511 setups. He said: ``Well, some instructions )take longer and you need to poll for completion''. ``Oh, lke which )ones'' I asked. ``Like divide'' he said. Oh. You mean you didn't call him dork or dipshit? )))Every time I pumped him for information, he pumped me )))wanting to know how many i needed, so thay could make their )))projections and deicide to make this chip or not. ))Should have asked for a sample ;-) )Of what ? Their board ? Dont be a dork. It isn't a chip yet. But )I said that. What's the matter Richard? Ever hear of engineering samples? If they are talking about the part, then they *should* have samples to give to the designers to use to build proof of concept boards. If they don't have anything to give you, then they are not for real. Besides they would have at least sent you a 3116 with an ap note on how to interface it to your favorite processor. ))I don't like Weitek. )Oh, well thats it then. Steve Berry doesnt like Weitek. They may as )well close up shop right now. I'm calling my stockbroker right )now to tell him. )So use the instructins that do work, dipshit. The Weitek part )on a (IBM) PC gets about 3X the equiv 'x87 performence. Christ. On an IBM PC that may be just peachy. When you are building a board that needs absolute speed, runs it's own code concurrent with the host processor to do dedicated Goureau (sp??) shading of 200K 3D polygons/sec, the last thing you need to deal with is vendor bugs. Especially when they know about them in advance and conviently forget to inform you. )Oh, that explains it. And theres two t's in nuttin'. Clever. Which stooge were you? )richard@gryphon.COM decwrl!gryphon!richard gryphon!richard@elroy.jpl.NASA.GOV This discussion has gone beyond anything remotely Amiga specific. I suggest that if you (yes you Richard) are interested in continuing the thread that we move to another news group, or e-mail. Based on the tone of this flame, it's hard for me to believe that anything of interest is forthcoming. -- Steve -Raz- Berry Disclaimer: I didn't do nutin! UUCP: sun!kilowatt!raz ARPA: raz%kilowatt.EBay@sun.com "Fate, it protects little children, old women, and ships named Enterprize"