chad@cup.portal.com (Chad The-Walrus Netzer) (12/25/89)
*Sigh* I couldn't let this one pass because of the incredible amount of misinformation. Sorry to prolong the thread. This contains a largely individual refutation of inaccurate facts that were posted. If you're not interested, skip it. It IS rather long... Now, let me start this at the beginning... In a previous article, (Stanley T. Chow) writes: ) <668@bmers58.UUCP> keithh@atreus.UUCP (Keith Hanlan) writes: )> <1617@bnr-rsc.UUCP> bcarh185!schow@bnr-rsc.UUCP (Stanley T.H. Chow) writes: )>>For myself, I prefer the Intel approach - that is, make the successors )>>have exactly the same bugs as well. That way, a pin-compatible '010 will )>>really be pin-compatible. )> )>Come now Stanley, you're going to get roasted for this one so let me )>start :-) ) )This depends on your point of view - do you want a pretty architecture )or do you want to get some work done. ) )For example, are you happy that the MOVESR instruction is priviledged on )the '010? Or would you rather see it the same as the '000 so that we can )drop '010 into the '000 socket and not worry about decigel, etc.? What )did this change buy us? The *conceptual* ability to virtualize a '010! )Whoppie. How many people do you know run virtual '010? How many simply )use the '010 as a faster '000? Yes, I am very happy they made this CHANGE of the MOVESR instruction (a change that they warned everyone they might make), as well as fixed the BUG in the 68000 in which not enough information was saved on the stack to allow it to recover from page faults (without the two 68000 hack). In fact, LOTS of people are glad the 68010 was made this way... I own a UNIX PC (by AT&T) that uses a 68010. The machine supports paging, and has an MMU. The 68010 allows this machine to run UNIX. Motorola made the 68010 so that machines like this could exist. Furthermore, they made the 68010 pin compatible with the 68000 because, first of all, there was no real hardware reason to redesign it, and secondly, because it could then replace many of the existing 68000's. Being pin compatible means that engineers don't have to redesign buses and timing circuits and other things just to accomodate the new chip. This saves them lots of time and money. Besides, many people were already familiar and experienced with 68000 hardware, and they didn't have to re-learn a lot of things to use it. More time and money saved. Don't be so egocentric as to think that the 68010 was developed SOLELY to allow Amiga owners to get a slight speed boost... I use a 68010 in my Amiga and have had virtually NO incompatabilities. The ones that I did have were a few games and one PD program). I lose no sleep over this because all my animation, ray tracing, painting, programming, and other utilities work fine. I do get a slight (and noticeable) boost in speed, and since I got my 68010 for $6, I consider it worthwhile. People who play games a lot, really shouldn't get an '010... It was in Motorola's (and the computer industry in general) best interest to make the 68010, but not because of a slight speed increase. Even if the 68010 performed at EXACTLY the same speed as the 68000, it would be worth making, although not worth putting in an Amiga. In short, Motorola had GOOD reason to make the 68010 the way they did, and MANY companies thought so too, because they used it without any problems (of the sort you claim). )>>How about the ['030] MMU being a subset of the '851 MMU? Not a bug, but )>comments on this. If you really need it - which most will contend you )>don't - add the '851 anyways. ) )This is what I call a bug in the "Family Architecture": put an MMU into )the CPU just so that you can disable it and add an off-chip MMU. Brillant )use of the silicon real estate. Keith is wrong here... Dave Haynie has already stated why there is NO reason reason to use a 68851 with a 68030, and in fact CANNOT be used by a 68030. The 68030 has ALL the necessary items for effective use, and only the excess baggage was cut out. A person without his appendix is a 'subset' of a "normal" person, but is he rendered unuseable or compatible??? Intel put an MMU in their chip, why don't you call that a "bug"? Because you KNOW it is not... In a later article (Stanley T. Chow) writes: )Please note that I have nothing against fixes (or any changes). I just think )there are better times and worse times for making them. E.g., if the '010 )was/is intended as replacement for the '000 and the change is painless, )then Motorola should just drop the '000 all together. The 68010 was NOT meant as a "replacement" for the 68000, but rather as a chip that has several advantages over the 68000. And because Motorola KNOWS how to design chips correctly, it was even pin compatible with the 68000, and MOSTLY software compatible. Operating systems with the right design have no problem with it. ) The fact the Motorola still sells mostly '000 means either people think the )change is hard or that the people think the change is not worth it. Case in )point - Amiga after 4 release still does not support it. ^^^^ ^^^ ^^^^^^^ Here is where you are REALLY confused! The 68000 is still sold because it is cheaper to get than the 68010, and many customers don't NEED the 68010. Also, the 68000 has a higher maximum clock speed rating than the highest speed 68010 (ie. some 68000's can go at 16MHz, while 68010's can only go at 12Mhz). For application where the 68000 is just being used as a control chip or a work horse (ie. Laser Printers, Arcade Game machines, Sega systems, certain thermostats, etc.) a cheaper 68000 is better than a more expensive 68010, even though they will BOTH work. As for for saying that the Amiga's operating system "still doesn't support it", you are WRONG!!!!!!! COMPLETELY!!!!! It has ALWAYS supported the 68010, and even the 68020 and 68030. Certain checks and test have to be made at bootup to adjust ANY system that wants to be compatible with these chips (including adjusting certain stack, interrupt, and trap routines) and the Amiga Exec does, and has ALWAYS done this each time you reboot. In fact, you can plug a 68010 into an Amiga an expect it to work because the Operating system will adjust itself to accomodate the chip. Certain other makers of computers who will remain nameless did not do this (until recently), and so they would NOT work with an '010. )Yes, I know the '010 is priced much higher, but it had a very short marketing )window and was essentially replace by the '020. It would have been much )more sensible to fix all the problems in the '020 since the software kernal )had to change anyway. No... Those people who only need the 68000, should only use the 68000 (unless they understand the risk of using the 68010). Those who need the 68010 (such as Sun, AT&T, Apollo, etc.) should use the 68010. Those who need the 68020... If the 68010 WASN'T pin compatible, would you THEN say it was worthwhile? If so, I am VERY GLAD you don't design processors. )In artivle <668@bmers58.UUCP>, Keith Hanlan writes: )> See Dave Haynie's earlier )>comments on this. If you really need it - which most will contend you )>don't - add the '851 anyways. ^^^^^^^^^^^^^^^^^^^^ Because you cannot, and there is no reason to anyways, Keith. )The point is not whether the two MMU's are individually good enough. The )point is also not whether the O/S can hide the difference. The point is )that they are different! And if you didn't know they were different, but you saw both the A2620 board and the A2630 board running UNIX, would you care? Or would you rather that they made the 68030 completely incompatible with the 68020 (and 68851), so that everything would be more expensive, take longer to build, and probably not be as fast or reliable anyways? The point is not whether the two MMU's are individually good enough, as you state. But you better believe it IS whether or not the Operating System is able to use both equally well, without the user knowing or caring... this is ALWAYS the case in a system designed for the real world. )Does this have anything to do with MOVESR? Are you saying MOVESR causes )occasional crashes? I would have put it into the annoying design-flaw )catagory. :-) The "annoying design flaw" is not requiring a purchaser of a 68010 to past a written examination, confirming that the know the reasons for and drawbacks of the 68010, so that people like you will actually understand it. Nobody requires you to put a 68010 in your Amiga. Motorola designed the chip to help computer designers make BETTER systems (Amiga or not), and neither they nor I care whether you put one in your Amiga... if you're worried by even the slighest bit about compatibility problems, don't use it. But please understand WHY it exists before you say ANYTHING about it. )My version says the update broke the old way of doing things needlessly )for new features that a user does not want. So DON'T upgrade!!!! Nobody is forcing you!!! Just remember that many people will be using the new features and will be very pleased with them, and will have NO problems with it. Saying that "users don't want the features" really means (in this case) that *YOU* want the features, and quite frankly, who cares if *YOU* want them or not... Many others WILL! )The point is: "If it ain't broke, don't fix it". )The real point is: "If it is broke, but nobody cares, don't fix it anyway". I agree with both points, unfortunately for you, NEITHER applies. And Finally, (Stanly T. Chow) writes: )You know, Charlie Gibbs asked for horror stories, I pointed out the MOVESR )*inconsistancy* and here you are calling it a *bug*! Boy, are you gonna to )get flamed by the Motorola-lovers. :-) For once, you have the facts straignt. MOVESR is not a bug, and for good software it does not matter. The Page fault problem was the bug that really made the 68010 necessary, and is properly handled by the Amiga's operating system (so well that you didn't even seem to KNOW there was a bug). This is VERY different from a bug in, oh let's say, the Multiply or divide instruction, which will matter to almost ANYONE using the chip... )>>For myself, I prefer the Intel approach - that is, make the successors )>>have exactly the same bugs as well. That way, a pin-compatible '010 will )>>really be pin-compatible. )> )>You are one sick puppy. You remind me of the fellow with the broken watch who )>won't get it fixed because he is used to the way it loses time, and having on e )>that worked would only confuse him. ) )You are one closed-minded loud-mouth sicko bleeding-heart conservertive. First of all, this is NOT political, and secondly, you HAVE spread more information than anyone around recently, so you are in no position to call anyone anything... (You SHOULD NOT have been provoked, though) Just remember this, NONE of the Intel 80??? line are pin compatible... NONE! Pin compatibility is mostly to allow redesign of HARDWARE with a minimum of expense. It is NOT so that you can get a chip that works EXACTLY the same but just a little bit faster at the same clock speed. As Amiga owners, we are lucky that both Motorola and the Amiga Operating System, allow for such an easy upgrade, but it is not your inalienable right to have a 100% compatible chip that is just a little faster. It is MUCH more of a cost matter than any convience matter. )>>How about the '020 MMU being a subset of the '851 MMU? )>Undesirable feature? How would you suggest implementing the I/O stuff, when t he )>MMU has been moved inboard and made inaccesible to the I/O? ) )Are you saying there is no other difference? As I recall, the difference is )quite a bit more than that. But then, I haven't checked the details for )quite sometime. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^ Or, perhaps, ever??? Like I said before, is there a difference between someone with an appendix, and someone without? Can you tell the difference unless they tell you (or you happen to see a scar)? Do they act differently? Do you say very misleading things about them too? And really, DOES IT MATTER TO YOU? It's the same with the 68030 and the 020/851... )Ohh, I get it. This is a clever way of saying that Intel does as badly as )Motorola! Well I wouldn't say that... (it is unfair to Motorola, after all) ) Why can't we discuss the 68K on its own merits? Do you consider )its case so weak that you have to bloster it with weaknesses of other )processors? You're right. I tried not to talk too much about Intel because it doesn't even remotely belong in this group. And the ONLY reason I posted this is because you said MANY things that were DEAD WRONG (in the FACT department). Your opinions are your own, and I can't refute them, UNLESS they are arrived at due to inaccurate facts, and especially if you try to spread those inaccuracies further. If you are unsure of your facts, don't post, because it only makes things worse, and it makes you look foolish. Finally, feel free to E-Mail me (If it is rational, I WILL try to respond), but now that things are cleared up, it would be better not to post anymore in this group (take it comp.sys.arch), unless it is flammatory, in which case DROP IT! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Internet: chad@ucscb.ucsc.edu Chad 'NET-zerver' Netzer -> AmigaManiac++ Home (!school time):chad@cup.portal.com "I got blisters on my fingers!" - J.L. R.I.P.
thad@cup.portal.com (Thad P Floryan) (12/26/89)
A comment from Dave H. re: the ``DeciGEL'' genesis prompts this posting. The program's name is a pun on the ``DiGel'' (tm) antacid remedy. For more details, browse the ``MC68010'' directory on Fish Disk #18 in which you'll find the DeciGEL source, the DeciGEL executable, and my reprint of Motorola's Technical Note regarding replacing 68000 CPUs with 68010 CPUs along with my docs on how to open the A1000 and exchange the CPU chips. If you don't have access to FF#18, here are the first few lines from the DeciGEL program's source code for your perusal: ;*************************************************************** ; * ; DeciGEL (Relief from MC68010 pains on the Amiga) * ; * ; Copyright 1986 by Scott Turner * ; Program may be copied and used for non-commercial uses only. * ; Requests for commercial use should be directed to: * ; * ; Scott Turner * ; 12311 Maplewood Avenue * ; Edmonds, Wa 98020-1115 * Sadly, there are still Amiga "developers" who controvert Amiga Programming Guidelines issued (in print) ever since the May 1985 DevCon. As many know, I and *MANY* others used to buy EVERYTHING that came out for the Amiga until we got burned once too many times by ill-designed or ill-coded software. Today I either port stuff over from my UNIX boxes to use on the Amiga or I write my own tools ... I simply CANNOT trust many so-called "professional" and/or commercial houses/developers to do their job correctly. A sad commentary on what I perceive the present Amiga software market to be. At least *MY* Amigas stay up for months at a time and experience NO gurus. I still do my "part" by featuring one of my office Amigas front-and-center during the once-monthly Advanced Software Seminars I teach at my primary company for my clients; it's the only "tool" that will do the job of driving robotic devices, a plotter, display Tektronix graphics, and demonstrate audio intermodulation effects simultaneous with my FFT demos using one of my software products (not even my 3B UNIX boxes can do THAT much at one time! :-) Thad Floryan [ thad@cup.portal.com (OR) ..!sun!portal!cup.portal.com!thad ]