How hard is to build a processor?
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From: Thad Smith on 26 Feb 2010 20:33 Jon Kirwan wrote: > On Fri, 26 Feb 2010 14:18:14 -0700, Bill Cooke > <bcooke(a)cookedata.com> wrote: > >> Joe Pfeiffer wrote: >>> Bill Cooke <bcooke(a)cookedata.com> writes: >>>> In 1961 a colleague told me of a machine in a lab at Cornell named >>>> CADET, which reputedly stood for "can't add, doesn't even try". >>> IBM 1620. See http://en.wikipedia.org/wiki/IBM_1620 >> Hah! My leg's been pulled. and to think I'd just finished a year on >> 1401, 705 code! I'd thought 'cadet' was a lab project, not a for-real >> machine. I've even read a 1620 manual, but never got to write for one. > I can remember hearing that phrase from time to time when I > worked on the 1620. It was a fun machine. I used to swap > out the colored bezels on the control panel just to tease. I was working at a small shop that had a hand-me-down 1620. They had a simple Fortran compiler, "PDQ Fortran", but it lacked some features they wanted. On my own, I wrote a disassembler for the 1620, disassembled the compiler, studied the code, figured out how to save some code space (memory was limited), then add some features, basically enhanced write commands and formatting, all with no external documentation. When the code was almost ready I was so excited I couldn't sleep, so went into work at 4 AM or such and got it working. Fun days! -- Thad
From: Joe Pfeiffer on 26 Feb 2010 20:39 D Yuniskis <not.going.to.be(a)seen.com> writes: > > In the early 80's it was common to build "custom" processors > out of 2900 bit-slice components. There was an excellent text > (and some good AMD appnotes) devoted entirely to this (Mick 'n' > Brick? yellow dust jacket). Yes, Mick and Brick. An absolutely outstanding book on datapaths. and microprogramming; it was all based on 2900-series, but the concepts mapped to everything. -- As we enjoy great advantages from the inventions of others, we should be glad of an opportunity to serve others by any invention of ours; and this we should do freely and generously. (Benjamin Franklin)
From: rickman on 26 Feb 2010 21:57 On Feb 26, 3:22 pm, D Yuniskis <not.going.to...(a)seen.com> wrote: > > In the early 80's it was common to build "custom" processors > out of 2900 bit-slice components. There was an excellent text > (and some good AMD appnotes) devoted entirely to this (Mick 'n' > Brick? yellow dust jacket). Yup! I read Mick and Brick cover to cover and learned a lot from it. I never built anything with bit slice other than on paper. But I have a lot of respect for those who did. I even used a "high end" workstation once that was a suped up 68000 made out of bit slice. I think it had a marketing window of 15 minutes before Moto came out with a 680xx or something much faster than the 68000. > Now, I am much more fascinated by electro-mechanical *mechanisms*. > I have been working on a kinetic "sculpture" to act as a timepiece > in the back yard. A tribute to Rube Goldberg -- with the exception > that it must run *continuously* (most of his contraptions were > "one-shot" devices). But, in order to keep *good* time, I need > to "close the loop". Doing so without being noticed means > using some "non-discrete" device that you can control. I.e., > something like a liquid whose rate of flow can be varied without > a critical observer being able to *easily* determine that this > is happening. Living in the DSw poses a problem using water as > it evaporates too fast (replenishing it from the domestic water > supply would be "cheating" :< ). I also need to locate some > larger solar panels so the device has no connection to the electric > utility. I have thought about how to make a time piece that is actually regulated by the flow of water. It would be hard to get this to be accurate, but I havae some ideas on how to make it fairly good. I am in the mid-east US, so we normally have lots of rain. I have thought about ways to make it "self-winding". One is to simply catch rain from the roof and keep the top reservoir full. Another would be to use wind power to pump water from the lower reservoir to the top. That would be doubly cool. It might even allow the clock hands to be in front of the windmill blades! But this project is way off in the distance. I have many other things to do first. Rick
From: D Yuniskis on 27 Feb 2010 00:49 Hi Rick, rickman wrote: > On Feb 26, 3:22 pm, D Yuniskis <not.going.to...(a)seen.com> wrote: >> In the early 80's it was common to build "custom" processors >> out of 2900 bit-slice components. There was an excellent text >> (and some good AMD appnotes) devoted entirely to this (Mick 'n' >> Brick? yellow dust jacket). > > Yup! I read Mick and Brick cover to cover and learned a lot from it. > I never built anything with bit slice other than on paper. But I have > a lot of respect for those who did. I even used a "high end" > workstation once that was a suped up 68000 made out of bit slice. I > think it had a marketing window of 15 minutes before Moto came out > with a 680xx or something much faster than the 68000. AMD published a lot of app notes and manuals that really catered to the 2900 family of devices. In my Great Databook Purge, they are among the few items that I kept! (along with Mick 'n' Brick, of course!) >> Now, I am much more fascinated by electro-mechanical *mechanisms*. >> I have been working on a kinetic "sculpture" to act as a timepiece >> in the back yard. A tribute to Rube Goldberg -- with the exception >> that it must run *continuously* (most of his contraptions were >> "one-shot" devices). But, in order to keep *good* time, I need >> to "close the loop". Doing so without being noticed means >> using some "non-discrete" device that you can control. I.e., >> something like a liquid whose rate of flow can be varied without >> a critical observer being able to *easily* determine that this >> is happening. Living in the DSw poses a problem using water as >> it evaporates too fast (replenishing it from the domestic water >> supply would be "cheating" :< ). I also need to locate some >> larger solar panels so the device has no connection to the electric >> utility. > > I have thought about how to make a time piece that is actually > regulated by the flow of water. It would be hard to get this to be > accurate, but I havae some ideas on how to make it fairly good. I am I plan on cheating: detecting the "displayed time" and using that in a feedback loop to control the pump speed. It would probably need to be a terribly overdamped control system given all the other "cruft" between the pump and the "display". > in the mid-east US, so we normally have lots of rain. I have thought > about ways to make it "self-winding". One is to simply catch rain > from the roof and keep the top reservoir full. Another would be to > use wind power to pump water from the lower reservoir to the top. Yes, that's my approach. We don't have enough rainfall to "self wind". I suspect it would be very difficult to keep enough water in the system to span the gaps between rains! (or, if you could keep enough water, trying to keep that water "clean" of algae, etc. over that long of a time period). We get *lots* of sun so PV seems to be an essential part of any solution. > That would be doubly cool. It might even allow the clock hands to be > in front of the windmill blades! Ah, I don't plan on displaying the time in such a "traditional" format. :> I don't want folks to recognize it as a timepiece unless they *know* how to "read" it. Instead, it will just look like a kinematic sculpture... > But this project is way off in the distance. I have many other things > to do first. <grin> Yup. In my case, the problem is figuring out what *will* work "on paper" before investing lots of time building something that just turns out to be a nonfunctional eyesore.
From: Joe Pfeiffer on 27 Feb 2010 00:47
The clock/calendar I hope to build over the next year or so will be solar. The shadow of a post uniquely determines both date and time, if you look at both angle and length.... -- As we enjoy great advantages from the inventions of others, we should be glad of an opportunity to serve others by any invention of ours; and this we should do freely and generously. (Benjamin Franklin) |