- test-drb@ccmp.vtda.org - classiccmp.org

Needed: RM80 (for KS10 restoration project)

by acorda＠nswc.navy.mil

I've finally managed to partially satisfy my nostalgic obsession to resurrect a PDP-10. I just recently located a KS10, and, after a 480 mile mile trip in the back of my poor little pickup truck, it is now safely sitting in front of my garage (still in the truck... It will be _in_ the garage as soon as I can con a couple of my friends into giving me a hand. This is not a light load :-) The next thing I'm going to need is a Massbus drive (preferably, an RM80) If anyone has one of these that they would be willing to part with, please drop me an email note. I'm located in Virginia, but I'm willing to drive a reasonable distance to pick one of these critters up (the closer the better, of course :-) Shipping would be impractical. The other possibility is to build an adapter that I could stick in a PC which would emulate a Massbus device, but to do this, I'd need pretty complete specs on the Massbus (i.e. pinouts, timing, etc.) Does anyone happen to have this info? I've done a dejanews search, but nothing really useful turned up. If I can locate a partially complete RM80 (i.e. one with the Massbus to modified-SMD adapter still present and intact in the drive pedistal, then I might try to build an adapter to emulate the modified-SMD interface supported by the massbus adapter cardset. I suspect this might be a simpler emulation, but it would still require info on the modified-SMD interface supported by the RM80. If anyone has details on this interface, please let me know! BTW, I'm also on the lookout for TOPS-10 and/or TOPS-20 load tapes (or images thereof, or bits and pieces... whatever I can find that will get me closer to bringing this critter back to life! -Thanks in advance... -al -acorda(a)geocities.com

26 years, 11 months

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Apple stuff....

by ethan_dicks＠yahoo.com

--- Jason Willgruber <roblwill(a)usaor.net> wrote: > Does anyone have (or know where to get) an old (b/w) Apple > ImageWriter printer for under $20? I have an untested ImageWriter that I got last month that was attached to the Apple //c+ that was the object of my interest. I would be willing to let it go for $20 plus shipping. > I also need a cable to connect an Apple //c to a printer. I only have the one cable that came with the //c+. I could get you the pinout if you needed it. -ethan _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com

26 years, 11 months

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microcode, compilers, and supercomputer architecture

by clintw＠colorado.cirrus.com

> > ::> > I have heard of Airbuses crashing because the controls were poorly > ::> > designed. I've never heard of a 777 crashing. I've also never heard of any > ::> > medical machines failing, though this would tend to be underpublicized. > > ::Actually, the THERAC-25 radiation therapy machine is a good example of > ::poor hardware AND software design which killed a number of people by > ::giving them too high a dose of radiation, either for too long or > ::without the proper screen in place. > > !?! > > Has this been documented anywhere? Where did you find this out from? > I read an article about it several years ago, but I don't remember what magazine it was it... One of the IEEE or ACM periodicals, I think. A quick Alta-Vista search on "therac" turns up 476 matches, but a lot of them are CS student papers. Take a look at http://ei.cs.vt.edu/~cs3604/lib/Therac_25/Therac_1.html This is a reprint from IEEE Computer (might even be the original article I saw :) clint

26 years, 11 months

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microcode, compilers, and supercomputer architecture

by clintw＠colorado.cirrus.com

> > > Max Eskin <max82(a)surfree.com> wrote: > > > > I have heard of Airbuses crashing because the controls were poorly > > designed. I've never heard of a 777 crashing. I've also never heard of any > > medical machines failing, though this would tend to be underpublicized. > Actually, the THERAC-25 radiation therapy machine is a good example of poor hardware AND software design which killed a number of people by giving them too high a dose of radiation, either for too long or without the proper screen in place. clint

26 years, 11 months

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Lisp, the machine language. Was Re: Hallelujah!

by ss＠allegro.com

William writes: > My wish is for a computer system that provides for dynamically modifiable > microcode, so that my self-modifying programs could obtain a new level > of self-modifyability! Ah..a few decades too late :) The Burroughs B1700 (and B1800 and B1900) could have been used that way, I suppose. The machine had multiple microcode sets, executed by picocode. (IIRC, Picocode was written in an ALGOL-like language) I don't recall seeing any particularly protection mechanism that would have prevented you from modifying a microcode on the fly. The COBOL compiler determined which microcode to use, based on things like the number of variables used by the program being compiled. (If a program used a small number of variables, it could be compiled to a microcode instruction set that had more compact instructions because the number of address bits was smaller.) Another microcode instruction set was used for the primary OS programming language (SPL? XPL? can't recall). I seem to recall several other microcode sets being around as well. When processes were "time sliced" (multi-programming), the microcode was also time sliced. (I.e., process A might be using one microcode, while "simultaneously" process B might be using a different microcode). > As for the Lisp difficulties, remember, it takes only a few of the basic > operators to define the language. All else can be derived from same, > and AFAIK is derived from same. So, there is no need to implement > derivable functions in microcode. > > William R. Buckley >

26 years, 11 months

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FA: Compucolor II

by adavie＠mad.scientist.com

As the title says, I'm selling my Compucolor II computer. The URL is http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=87600036 I'm diverting my collecting interests into other areas, and need $$$ Cheers A

26 years, 11 months

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homemade computer for fun and experience...

by edick＠idcomm.com

You're quite right that most software license agreements decline to warrant "suitability for any specific purpose," as a matter of the boilerplate, but DEC sales agreements, not the licenses, specifically dodged the question of their software doing anything of use at all. In any case, I found that distasteful and, from the point at which I learned of that, declined ever to associate myself with any DEC hardware or software again. I doubt that it's cost me even a dime to do so. Dick -----Original Message----- From: Ward D. Griffiths III <gram(a)cnct.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Monday, April 05, 1999 10:27 PM Subject: Re: homemade computer for fun and experience... >On Tue, 6 Apr 1999, Computer Room Internet Cafe wrote: > >> I've yet to see ANY software license that guarantees the software will >> actually DO anything. Some do guarantee to take up space on a disk. >> That's about it. > >Actually, I've never seen a software license that guarantees to take >up disk space, though the bit on the outside generally implies you'd >best have a bunch to spare. Hell, I've only seen one _printed book_ >with a space guarantee, when Robert A. Heinlein in his _Expanded >Universe_ promised that the book would contain enough pages to hold >the covers apart or your money back. (Mind you, lots of computer >documentation would fail _that_ promise if they attempted it, be it >hardware or software manuals). >-- >Ward Griffiths >"the timid die just like the daring; and if you don't take the plunge then >you'll just take the fall" Michael Longcor >

26 years, 11 months

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OT: early rising (was: RE: Timonium Hamfest)

by Philip.Belben＠pgen.com

> What is it about hamfests that cause otherwise > sane individuals to get up at the crack of dawn? > > Almost every computer involved person I know who > has any control of their work schedule: > > 1) Gets up after the sun has properly warmed the earth > where they live > 2) Eats lunch for breakfast > 3) Eats dinner for lunch > 4) Has Chinese delivered at 1 a.m. for dinner > 5) Sleeps till 2 or 3 p.m. on Saturday if at all possible Like, I imagine, most people on this list, I do not regard myself as sane. That said, I think the morning is a sadly under-rated time of day. My alarm clock goes off at 6 am whether I need to go to work or not. I get up any time between 6.00 and 7.15 on work days, 6.00 and 8.00 on other days. It is not quite random - if I have been short of sleep lately, or am in the middle of a good book, I tend to get up later. And I find it quite hard to do anything remotely involving the brain after 10pm. Am I really that unusual? Philip.

26 years, 11 months

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ABS - or is it Pure BS

by allisonp＠world.std.com

<Aircraft Tragedies' shows, big airplanes aren't maneuvrable enough to turn <while they're skidding. And don't they turn by adjusting the engine thrust <anyway? It's so they come to a stop. How else would you bring a 747 at 400,000 pounds from 140+knots to 0 in less than 7000 feet! Turning is a whole different process. I feel comfortable discussing this as a pilot on this point. Allison

26 years, 11 months

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this is not rec.autos

by SUPRDAVE＠aol.com

In a message dated 99-04-06 02:39:31 EDT, you write: << it certainly has me squealing... At 11:24 PM 4/5/99 -0700, Joseph S. Barrera III wrote: >... but it sure seems like it, lately. Can't we put the brakes on the ABS >discussion (as it were :-)? >>

26 years, 11 months

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ABS - or is it Pure BS

by allisonp＠world.std.com

<they always seem to lock up. Well, the pumping action occurs but, at each <application of the pump, I notice wheel lock-up. There is no stopping. < <William R. Buckley I live in New England and nothing works on ice but ABS works better. If your sharp and have ice racing experince you MIGHT do better manually. The average idiot on the road driving a 2.5ton SUV doesn't qualify. The put ABS on BIG airplanes for a reason and not for the added weight. Allison

26 years, 11 months

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OT Simulators was Re: ABS - or is it Pure BS

by netcafe＠pirie.mtx.net.au

-----Original Message----- From: Ward Donald Griffiths III <gram(a)cnct.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Tuesday, 6 April 1999 14:16 Subject: Re: ABS - or is it Pure BS >Computer Room Internet Cafe wrote: > >> With all due respect, IMHO, simulators that are not mounted on big hydraulic >> jacks and convince you that you are in a real aeroplane are not much chop >> for anything except perhaps teaching instrument flying, and fairly limited >> in that area. > >Even those have their limitations. The C5A simulator I used to >service wouldn't tilt past 25 or so degrees from horizontal, so >there was no way to practice a barrel roll. (Yeah, the computer >flight sims will let you do that, but they don't teach you how to >think with all of your heart's blood pressing on your brain). Exactly. They also don't teach you to trust your instruments when your middle ear is trying to convince you that you are flying straight and level when in fact you are in a descending left spiral. You just don't get the feedback in your loungeroom. The best sims in the world can't duplicate that experience, but they are at least enough to give you an idea. I know that people have been airsick in the P3 sim at RAAF Edinburgh when they have turbulence dialled in. It's fairly convincing for most things. They can't quite duplicate the separation of the wing leading edge when the aircraft is overstressed, but they can at least reproduce the conditions. (Real Orions are known to do that, we lost one at Cocos Island a year or two back that way, not a fault of the aircraft, it was being, ahem, mishandled at the time.) >I'll admit I'm not the engineer to build a decent _large_ >aircraft simulator to give that experience -- part of the deal in >the C5A simulator was the fact that it was a rather large object >with a bunch of people in the cabin, hard to make that realistic >sticking the pilot (or navigator or flight engineer) in a closet. Suspension of disbelief is fairly vital if the simulator experience is to have much usefullness when related to the real world. It's got to feel real enough to make you forget it's not an aeroplane, and it's got to behave like the real aeroplane as much as possible without antigravity assistance. Cheers Geoff Roberts

26 years, 11 months

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homemade computer for fun and experience...

by gram＠cnct.com

On Tue, 6 Apr 1999, Computer Room Internet Cafe wrote: > I've yet to see ANY software license that guarantees the software will > actually DO anything. Some do guarantee to take up space on a disk. > That's about it. Actually, I've never seen a software license that guarantees to take up disk space, though the note on the label generally implies you'd best have a bunch to spare. Hell, I've only seen one _printed book_ with a space guarantee, when Robert A. Heinlein in his _Expanded Universe_ promised that the book would contain enough pages to hold the covers apart or your money back. (Mind you, lots of computer documentation would fail _that_ promise if they attempted it, be it hardware or software manuals). -- Ward Griffiths "the timid die just like the daring; and if you don't take the plunge then you'll just take the fall" Michael Longcor

26 years, 11 months

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homemade computer for fun and experience...

by netcafe＠pirie.mtx.net.au

-----Original Message----- From: Ward D. Griffiths III <gram(a)cnct.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Tuesday, 6 April 1999 12:16 Subject: Re: homemade computer for fun and experience... >On Mon, 5 Apr 1999, Richard Erlacher wrote: > >> I have never had a desire for DEC hardware, mainly because of my distaste >> (and disdain) for their application of technology, and of course for their >> overemphasis on the bottom line, meaning THEIR bottom line. If you read the >> fine print, their sales documents specifically deny that they claim their >> products work. argghhh! I'm GLAD they're gone. THEY were the reason I had >> to have terminals around as long as I did. > >Ever read a MICROS~1 license agreement? The DEC sales material wasn't >binding. I've yet to see ANY software license that guarantees the software will actually DO anything. Some do guarantee to take up space on a disk. That's about it. Cheers Geoff Roberts

26 years, 11 months

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ABS - or is it Pure BS

by netcafe＠pirie.mtx.net.au

-----Original Message----- From: Max Eskin <max82(a)surfree.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Tuesday, 6 April 1999 12:27 Subject: Re: ABS - or is it Pure BS >On Mon, 5 Apr 1999, Allison J Parent wrote: > >>It's so they come to a stop. How else would you bring a 747 at 400,000 >>pounds from 140+knots to 0 in less than 7000 feet! > >So, why do you need ABS if you are just landing straight? So that it doesn't :- 1) Beat the hell out of the tyres any more than necessary. ABS tends to prolong tyre life by reducing damage that occurs during braking, like flat spots. Aircraft tyres have a hard life at best (0 to 140kts in 1 sec or so.) 2)On a slippery (read wet/icy) surface, they extract maximum braking performance without reducing control. Consider the footprint of a 400,000ib aircraft in comparison to a large truck. The truck has considerably more rubber per lb of weight on the surface. The aircraft needs all the help it can get. Basically, if all runways were clean, dry and provided max braking at all times, it's probably possible to live without it, but they aren't like that, so it's very desirable. Cheers Geoff Roberts VK5KDR

26 years, 11 months

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ABS - or is it Pure BS

by netcafe＠pirie.mtx.net.au

-----Original Message----- From: Max Eskin <max82(a)surfree.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Tuesday, 6 April 1999 11:29 Subject: Re: ABS - or is it Pure BS >On Mon, 5 Apr 1999, Allison J Parent wrote: >>The put ABS on BIG airplanes for a reason and not for the added weight. > >I don't know if my Microsoft Flight Simulator experience is worth >anything, With all due respect, IMHO, simulators that are not mounted on big hydraulic jacks and convince you that you are in a real aeroplane are not much chop for anything except perhaps teaching instrument flying, and fairly limited in that area. >but judging by what I've seen both in it and in various 'Worst >Aircraft Tragedies' shows, big airplanes aren't maneuvrable enough to turn >while they're skidding. The whole point of abs on a heavy aircraft is so they DON'T skid. My experience with virually all vehicles is that they are difficult to maneuvre whilst skidding! Can't comment on the snow and ice issue, (never see that around here) but abs can be hazardous on gravel roads (we have lots of them) IF the driver is not aware of, and trained in the way it affects vehicle handling. Many of our urban brethren manage to come unstuck on gravel, country boys don't seem to have much trouble, whether they have abs or not, so I suspect the biggest factor is not the vehicle or it's braking system, but the skill level of the driver and the degree of familiarity with the vehicle, it's handling and the road surface.. >And don't they turn by adjusting the engine thrust Not since the DC3 days. No, they have steerable nosewheels, attached to the rudder pedals, or to an auxiliary steering wheel. Steering with differential throttle may be used to ASSIST in turning an aircraft, but not on it's own, unless the nosewheel steering has failed. Geoff Roberts VK5KDR 200+ hours in various light aircraft. 10 years in Air Traffic Services 5 of 'em at Sydney Kingsford-Smith. 5 in the bush 300 miles from anywhere.

26 years, 11 months

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IBM 5150 PC disk drive questions

by roblwill＠usaor.net

O.K. I think I have it figured out. I'll have to either get a cable for the external drives (or make one). I was thinking that the 4869 was the drive that would be used with the 5170, but it isn't. Was there a drive box available from IBM for the 5150 (or was that the expansion chassis)? ThAnX, -- -Jason Willgruber (roblwill(a)usaor.net) ICQ#: 1730318 <http://members.tripod.com/general_1> -----Original Message----- From: Joe <rigdonj(a)intellistar.net> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Monday, April 05, 1999 1:33 PM Subject: Re: IBM 5150 PC disk drive questions >Jason, > > The external cable had two connectors and a twist in it just like the >internal one. > > > Joe > >At 01:29 PM 4/5/99 -0400, you wrote: >>According to the jumper settings on the 5150, it appears that 4 floppy >>drives can be connected to the computer. How is this possible? I'm >>guessing 2 internal, and two external, but there's only one connector for an >>external drive, so it would only allow 3 drives. >>Or is there a special controller that has dual external ports? >> >>Any suggestions? >> >>ThAnX, >>-- >> -Jason Willgruber >> (roblwill(a)usaor.net) >> ICQ#: 1730318 >><http://members.tripod.com/general_1> >> >> > >

26 years, 11 months

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bringing up an 8f...

by allisonp＠world.std.com

<lamps but they are 5v versions rather than the 8v lamps of the original. I <do however minimize the hours on that panel since I worry about the lamps <burning out. (I've got three spares left ...) Even back when it was a common hack as well as commercial LED replacements for either 8E logic. If done as was common back then it would be legit. Oh the leds used then were ONLY available in red or IR. Replacement bulbs can be had as well but the LED fix is permanent. Allison

26 years, 11 months

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Fwd: TRANSFORMER

by cfandt＠netsync.net

For those who may need such a thing . . . Contact the poster directly, not me. >X-Mailer: Juno 2.0.11 >Date: Mon, 5 Apr 1999 20:56:34 -0400 >Reply-To: jimconners(a)JUNO.COM >Sender: Heathkit Owners and Collectors List <HEATH(a)LISTSERV.TEMPE.GOV> >From: Jim Conners <jimconners(a)JUNO.COM> >Subject: TRANSFORMER >To: HEATH(a)LISTSERV.TEMPE.GOV > >Hi, >I just found tucked away a brand new transformer for an H-89 computer. >It is marked 54-969 and 172-7575 on the tape on the box and it is marked >54-969 and 60-8204 on the transformer. I was wondering if anyone knew if >this part may have been used in any other Heathkits. I doubt anyone is >repairing an H-89. >Thanks, >Jim > >--- --- --- --- --- --- --- --- --- --- --- --- --- -- >To subscribe: listserv(a)listserv.tempe.gov >and in body: subscribe HEATH yourfirstname yourlastname >To unsubscribe: listserv(a)listserv.tempe.gov >and in body: signoff HEATH >Archives for HEATH: http://www.tempe.gov/archives >--- --- --- --- --- --- --- --- --- --- --- --- --- -- Christian Fandt, Electronic/Electrical Historian Jamestown, NY USA cfandt(a)netsync.net Member of Antique Wireless Association URL: http://www.ggw.org/awa

26 years, 11 months

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ABS - or is it Pure BS

by roblwill＠usaor.net

This winter, I had a small argument with my dad as to who's car would stop faster - his 1994 Ford explorer, or my 1983 AMC Wagoneer. He claimed that his would stop faster because of the ABS. We both drove to the top of the hill (about 200 feet, 30 degree slope - snow covered). We went down the hill at separate times, each going 15 MPH at the time the brakes were applied. The Jeep, without ABS, and the same type of tires as the Ford (Firestone ATX - studded), stopped about 5 feet shorter than the Ford. Anyone know the average weight of a Ford Explorer? I know the Jeep weighs 5,975 lb., but I have to figure in the weight of the Ford to find out accurately. -- -Jason Willgruber (roblwill(a)usaor.net) ICQ#: 1730318 <http://members.tripod.com/general_1> -----Original Message----- From: Buck Savage <hhacker(a)home.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Monday, April 05, 1999 3:19 PM Subject: ABS - or is it Pure BS > >>2) even if the ABS system fails it still works just like non-ABS brakes. >unless >>the vacuum (power assisted) system fails or the brake line is cut, or (very >>unlikely) the piston sticks open, the brakes will work just fine. >> > > >ABS - American Bull Shi... > >I have noted one difficulty with ABS, and that is its failure to operate on >snow >and ice. Since I live in Southern California, I do not get that much snow >but, >in any quick application of my Mustang's breaks, on snow covered roads, >they always seem to lock up. Well, the pumping action occurs but, at each >application of the pump, I notice wheel lock-up. There is no stopping. > >William R. Buckley > >

26 years, 11 months

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bringing up an 8f...

by geoffrob＠stmarks.pp.catholic.edu.au

-----Original Message----- From: Eric Smith <eric(a)brouhaha.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Tuesday, 6 April 1999 04:29 Subject: Re: bringing up an 8f... >So in the context of this discussion about scanned documents, you're saying >that you either want them OCR'd or not at all? No. Any form of document is preferable to none at all, if that is the option. I was simply stating a preference. It's not an ideal world, nor is there an ideal solution. >I've received complaints like that about my site. Fortunately I'm not as >thin-skinned as some people, or I might have simply removed the scanned >images a long time ago. Not from me. Anyone who takes the time to provide online docs in any form has my gratitude. Whether their method of choice or necessity is the one I like or not. Kindest Regards Geoff Roberts >

26 years, 11 months

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IBM 5150 PC disk drive questions

by edick＠idcomm.com

Well, maybe, but the box of them that I had had no twist, hence would not access drive1. Perhaps it wouldn't do drive 2 either. I certainly never tried them because my need for these cable was for the connectors. I was glad there were no twists because it meant I could use the cables less the DC37 connector. They were useful as hard disk cables. Dick -----Original Message----- From: Joe <rigdonj(a)intellistar.net> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Monday, April 05, 1999 2:39 PM Subject: Re: IBM 5150 PC disk drive questions Jason, The external cable had two connectors and a twist in it just like the internal one. Joe At 01:29 PM 4/5/99 -0400, you wrote: >According to the jumper settings on the 5150, it appears that 4 floppy >drives can be connected to the computer. How is this possible? I'm >guessing 2 internal, and two external, but there's only one connector for an >external drive, so it would only allow 3 drives. >Or is there a special controller that has dual external ports? > >Any suggestions? > >ThAnX, >-- > -Jason Willgruber > (roblwill(a)usaor.net) > ICQ#: 1730318 ><http://members.tripod.com/general_1> > >

26 years, 11 months

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IBM PC disk drive questions

by edick＠idcomm.com

I once had a box of "External Drive" cables for a PC. These were terminated in a DC37 at one end and had straight (no twist) cable to the two edge connector sockets, ostensibly for drives 2,3,or 4. This arrangement ostensibly allowed for up to four drives. Dual external ports certainly wouldn't be needed with this arrangement. Dick -----Original Message----- From: Jason Willgruber <roblwill(a)usaor.net> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Monday, April 05, 1999 11:43 AM Subject: IBM PC disk drive questions >According to the jumper settings on the 5150, it appears that 4 floppy >drives can be connected to the computer. How is this possible? I'm >guessing 2 internal, and two external, but there's only one connector for an >external drive, so it would only allow 3 drives. >Or is there a special controller that has dual external ports? > >Any suggestions? > >ThAnX, >-- > -Jason Willgruber > (roblwill(a)usaor.net) > ICQ#: 1730318 ><http://members.tripod.com/general_1> > > > > > >

26 years, 11 months

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bringing up an 8f...

by allisonp＠world.std.com

<Alas it isn't... We're both right. The 8/e panel uses diode gates (in the <maintenance manual, printset and the physical machine on my desk). The <8/f uses TTL gates. The last 8e pannel I worked with was also ttl. there may have been two versions (very likely). The offending part was a 74L54 with a bad input. It's now mostly up and ready for more testing. Allison

26 years, 11 months

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VAX 6000/410 available in a couple of months

by pjt＠phxase.allied.com

Still under DEC maintenance. No licences for transfer. Specifications available on request. -- Philip J. Tait.....AlliedSignal Engines, Phoenix, Az.....pjt(a)phxase.allied.com

26 years, 11 months

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microcode, compilers, and supercomputer architecture

by hhacker＠home.com

>> Maximisation of processor throughput, and minimization of >> microinstruction count, is at least half the purpose of microprogramming. > >Sure. And the microcode compilers I've written and used are much better >at optimizing horizontal microcode than I have the time or patience to do >by hand. > Your lack of time and patience is not equal to the claim you make regarding the quality of optimisation possible. William R. Buckley

26 years, 11 months

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AIM65 ROM Images

by rcini＠email.msn.com

Hello, all: Does anyone have a copy of the AIM65 Assembler ROM and BASIC ROM that they can shoot me? I read the User's Guide and these seem like interesting programs to have :-). Thanks! [ Rich Cini/WUGNET [ ClubWin!/CW7 [ MCP Windows 95/Windows Networking [ Collector of "classic" computers [ http://highgate.comm.sfu.ca/~rcini/classiccmp/ [ http://highgate.comm.sfu.ca/~rcini/pdp11/ <---------------------------- reply separator

26 years, 11 months

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bringing up an 8f...

by CLASSICCMP＠trailing-edge.com

>On an interesting note is the availability of "white" LEDs (actually R, G, >and B leds all wired together in the same case). *Most* of the white LED's currently on the market are GaN (blue) LED's that illuminate a white-producing phosphor. The chromaticity indices of the resulting light is markedly different than you get from mixing R, G, and B. (Though this probably doesn't matter to anyone for this particular application...) > This leaves open the >possibility of replacing lamps with white LEDs continuing to keep the 8/e >in service as it was intended. (I also scavenge wheat lamps when I see 'em! It requires some small modifications, most noticably some way of dealing with the pre-heat current (usually done with a shunting resistor across the LED, though I have also seen schemes where a Zener or lifting a leg of the pre-heat resistor is done.) -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 11 months

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homemade computer for fun and experience...

by edick＠idcomm.com

While I agree fundamentally in that you really don't have to have graphic output capabilities, to wit, I did without it for over 30 years of computer use, I don't believe there's any reason to favor the terimnal over the direct-mapped monochrome video display. It's nominally a 2000 character window that has to be managed, and whether you do it with a terminal or with a video board is strictly up to you. I personally believe that exploiting the approach of the 6545 chip is still a pregnant way to address the problem of slow video updates due to low (<24.576Mbit/sec) baud rate. as for what you find difficult to get fixed . . . (a) who cares about fixing a serial card? Another costs $3. (b) pre-vga monochrome cards and monitors abound at the thrift stores. Keyboards do as well. (c) so long as hard disk drives of the ST506 variety still abound in the thrift stores, the controllers will too. I passed on an 'AT box a week ago, which had a VGA card, a 200+ MB eide 3.5" 1/3-height hard disk, and much of the usual stuff for $10. Had there been a decent keyboard, I might have gone for it, but there'll be others next week. I figure, if I can't replace it with something similar, then I'll replace it with something more current. Dick -----Original Message----- From: Tony Duell <ard(a)p850ug1.demon.co.uk> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 04, 1999 7:26 PM Subject: Re: homemade computer for fun and experience... >> >> Again, I have to agree about the "waste-of-trees" nature of most "technical" >> documents these days. Nevertheless, I find it easier to understand the >> result of a SPICE simulation when displayed graphically, e.g. with PROBE as > >There are, agreed, times when a graphical output is essential. I'd hate >it if my logic analyeser could _only_ give a list of the input states for >each sample (although sometimes that's what I want). More often, though, >I want a timing diagram. > >My handheld 'scope has an RS232 output that'll send the samples in >memory. Seeing those as a list of values is not often useful. Plotting >them is. > >However, the fact remains that often graphical output is _not_ essential. >I can't think why it would be superior to text-only output for >programming, for example. Or text processing - I do all my word processing >using TeX on a text-only machine. WYSIWYG would add absolutely nothing. > >> I already stated that the "old" machines did the "old" and in many instances >> quite persistent tasks well, and still would, given a chance. People have >> learned, however, that it's not as beneficial to have OLD hardware as to >> have new, not because of what it will do, but what it won't. I don't mean >> that it won't break. Any hardware can fail. It's a statistical reality. > >Although, to be fair, some of the older machines were rather >over-engineered, and less likely to fail than modern PCs... > >> However, if you try to repair that old, fine, terminal you bought in the >> '80's you'll find you can't get it fixed for less than the cost of a PC. > >_get_ it fixed? I fix things (anything) myself, and will continue to do so... > >> If, however, you break your PC, there's really nothing you can't repair or >> replace for much less than the cost of the original. > >Oh yes? Where do I find an ST506 controller from, new, these days? Or if >I am using a machine that uses such a drive and the controller fails, do >I have to replace the drive _and_ restore from backups as well? That's >hardly a good idea. Ditto for any video card that isn't VGA or higher, etc > >Fact is, swapping parts in PCs is easy, provided the PC is absolutely >modern. If it's even one generation behind, you start having problems >finding parts. Maintaining an old machine, where proper docs and spares >are _still_ available is a lot easier. > >What if I am depending on some hardware feature of the old card (like the >current loop interface on the IBM Async card. Ever tried getting one of >those, or a clone? > >-tony >

26 years, 11 months

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Single-Density PC-clone floppy controllers

by CLASSICCMP＠trailing-edge.com

For those who are putting together single-density-capable systems for use on a PC-clone (with Teledisk, 22Disk, and the like), they may find these articles from comp.os.cpm several months ago useful (or they may have additional data and/or contradicting data, which will be useful to the rest of us.) Enjoy! -Tim. Single Density on a PC (was Re: 22Disk and CompatiCard) Author: Amardeep S. Chana <asc1000(a)ibm.net> Date: 1998/12/30 Forum: comp.os.cpm Ken Ganshirt <ken.ganshirt(a)sk.sympatico.ca> wrote in article <36899CB0.19AD9093(a)sk.sympatico.ca>... > > I must have a pretty decent floppy controller, because I can even read > my original SS/SD Os-1 floppies, even though 22Disk warns that it might > not work for that format. (For the technically curious, this is on a > Dell 486/50 running Win 95 and the floppy drive is one of those deals > that has both a 3.5 and 5.25 in a single half-height drive. It's the > only system I have left with a 5.25" floppy drive.) > Ken, I recently did a study to find out what will and what won't do single density. Here are my findings so far: Will support single density / FM: NS PC87306 Super I/O SMC FDC37C65 SMC FDC37C78 Most SMC Super I/O chips Will NOT support single density / FM: NS 8473 NS PC87332* Super I/O NS PC97307* Super I/O WD FDC37C65 Most (if not all) Intel parts Any Winbond part Any UMC part Reportedly will do single density / FM but NOT verified: NS 8477 Intel 82077AA Goldstar Super I/O The NS PC87306 is found in a lot of Dell and Compaq machines from the 486-50Mhz models to the Pentium-90 models. Most Super Micro Pentium motherboards using the PCI HX chipset also used that super I/O. *NOTE: It is important to verify the part number on the chip itself. Many of these newer NS parts will identify themselves to software as PC87306, but do NOT support single density. Best regards, Amardeep _________________________________________________________________ Re: Single Density on a PC (was Re: 22Disk and CompatiCard) Author: Amardeep S. Chana <asc1000(a)ibm.net> Date: 1998/12/31 Forum: comp.os.cpm Don Maslin <donm(a)cts.com> wrote in article <915064276.933215(a)optional.cts.com>... [snip] > > Amardeep, I fear that I must question your study. I believe that you > are ascribing to some of the chips the shortcomings of the FDC > manufacturer. For example, both the NS 8473 and the WD 37C65 will > most assuredly support FM. I have DTK FDC cards with the 8473 and > read Osborne 1 disks with them just prior to writing this. Likewise, > I have the WD 37C65 in the WD FOX card and it will also read/write > FM. On that basis, I must have reservations about some of your other > determinations. > - don > Hi Don, I understand your reservations and can address every issue. I did not go into enough detail in the first posting to fully support my assertions. > : Will support single density / FM: > > : NS PC87306 Super I/O > : SMC FDC37C65 > : SMC FDC37C78 > : Most SMC Super I/O chips > The above parts are completely stand alone with on board filters, write precomp generators, and data separators. They should work with FM in any board implementation, unless something specific is done to prevent it (not likely). This is per the National and SMSC (new name for SMC semiconductor) data sheets. I have tested the NS PC87306 and SMC FDC37C65 using Jeff Vavasour's Model 4 emulator and Tim Mann's xtrs 2.8 under Linux. They both read and write FM with no problems. > : Will NOT support single density / FM: > > : NS 8473 > : NS PC87332* Super I/O > : NS PC97307* Super I/O > : WD FDC37C65 > : Most (if not all) Intel parts > : Any Winbond part > : Any UMC part > The 1988 data sheet for the NS 8473 states on page 8-32, "While the controller and data separator support both FM and MFM encoding, the filter switch circuitry only supports the IBM standard MFM data rates. To provide both FM and MFM filters external logic may be necessary." Every 8473 board I have tried failed to write FM. However, it may be possible to read FM on some boards if the external filters have a wide enough Q. The NS PC87332 & NS PC97307 are standalone and by design do not support FM (verified on the National data sheets). The only information I have on the WD FDC37C65 is the Always IN2000 card I have with that chip cannot read or write FM. I suspect it is also dependent on implementation. I have new information on Intel... Intel 8272 is a NEC 765 clone and therefore dependent on implementation . Intel 82077AA and 82077SL - data sheet clearly states these parts suppo rt FM. Thanks to Pete Cervasio for testing and reporting that the 82077 does indeed read and write FM. Intel 82078 - data sheet clearly states these parts will NOT support FM . I haven't yet investigated the new Intel Super I/O chip which is replacing the 82078. The Winbond and UMC chips have never worked on any adapter or motherboard I've ever encountered them on. No idea if its the chip or the implementation. > : Reportedly will do single density / FM but NOT verified: > > : NS 8477 > : Intel 82077AA > : Goldstar Super I/O > The NS 8477 data sheet indicates that it does support FM (it is functionally and pin for pin compatible with the Intel 82077). The Goldstar Super I/O was reported to work with FM in a newsgroup posting I read once but have never been able to confirm it. Hope that clarifies things :) Amardeep -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 11 months

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ABS - or is it Pure BS

by hhacker＠home.com

>Bill Pechter <pechter(a)pechter.dyndns.org> wrote: >> > ABS - American Bull Shi... >> > >> > I have noted one difficulty with ABS, and that is its failure to operate on >> > snow >> > and ice. Since I live in Southern California, I do not get that much snow >> > but, >> > in any quick application of my Mustang's breaks, on snow covered roads, >> > they always seem to lock up. Well, the pumping action occurs but, at each >> > application of the pump, I notice wheel lock-up. There is no stopping. >> > >> > William R. Buckley >> >> Noted the same thing with my wife's Acura in New Jersey. >> The bad news is (unlike the last two years) we usually get snow here. > >Hi > I think people miss the point here. First, nothing short >of retro rockets will slow you fast on snow and ice. The >best rule here is "SLOW DOWN". Even rainy or dew slick >roads reduce traction a lot. ABS' generally do much better >on ice and snow than can be done manually. Yes, they generally >lock and on lock but it is much better than complete lock >as all but a trained expert would do under such conditions. > I'm not all that great a fan of ABS but I think for anyone >not trained in skid control, it will do better than most >people would do. Skid training is something that has to >be learned as an automatic reaction. It requires regular >refreshing to keep the skill in tune. It can't be learned >by reading a book, it must be experienced. > ABS will not do magic, it will in most conditions give >one a better chance than they would normally have. It won't >make up for foolish drivers. >IMHO >Dwight > The detail here is that it occurs even with extremely light pressing of the brake (sorry for the earlier misspelling) peddle. Sure, very slow travel is the best course, which I judiciously demonstrate in my driving under such hazardous conditions. I, too, wonder how the computer knows (obviously, it does not) when lock is due to locking up as opposed to halted motion. William R. Buckley

26 years, 11 months

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microcode, compilers, and supercomputer architecture

by hhacker＠home.com

>[I'd suggested that we take this discussion off the list. I'm continuing >to reply here in this case only because I don't want people to get the >incorrect idea that Godel's Incompleteness Theorem can be used to magically >explain away any philosophical problem regarding computers.] > >> Is this use of the word "assembly" not yours? I, sir, am quoting you, not >> me! > >OK, that one was mine. It wasn't in the context you originally quoted, or >even from the same message you quoted >(<19990405060635.29296.qmail(a)brouhaha.com>). I had used it three >hours earlier in the discussion (<19990405030452.28640.qmail(a)brouhaha.com>). >So perhaps you see why I didn't understand what you were complaining about. >It is customary to include a brief quote of the actual context you are >referring to. > The quote was passed down several layers of reply. I expect one to remember one's own words. Your failure to do so does not provide any obligation on my part. >> That says nothing about the general case >> that humans have superior intellectual capacity vis-a-vis the computer. > >In the general case, I've never claimed that they do. I've only claimed that >in a sufficiently limited problem domain with a time limit (i.e., the solution >value vs. time curve is a flat with a sharp drop to zero), a computer may >reach a better solution than a human would. I also claim that this is true >for other common solution value vs. time curves; if the solution is worth $x >today but only $x/2 tomorrow, the computer may produce a more valuable >solution than would a human. > Time limits accepted but, that is not my concern. I am refering to an ultimate issue, which is that humans have intelligence, computers do not. Any high-speed moron has the opportunity to surpass a considerate intellect. Witness the ability of Deep Blue to challenge the best chess player. Yet, ultimately, a human can decide by means not algorithmic. >> What you have failed to address is that the human intellect is not limited >> by the capacity to algorithmatise a solution. >[and later:] >> Humans have the capacity to make judgements by means outside of those >> mathematical and logical, hence the reference to Penrose. > >Sure. A human may proceed in a manner that is not based upon logical >deduction or any (obvious) deterministic algorithm. > >It is yet to be proven that this human ability (as manifested in complex >problem-solving) is not equivalent to a non-deterministic algorithm, >or even to a sufficiently complex deterministic system. Penrose claims >that quantum uncertaintly is necessary to intelligence. While he provides >insufficient proof of this claim (really just anecdotal evidence), as an >argument against machine intelligence it is a red herring, since it is >not especially difficult to build a system that uses quantum uncertainty >to influence nondeterministic algorithms. > This begs the question, for proof is necessarily mathematical (I, for one, do not agree with Judicial notions of proof, such as a preponderance of the evidence). That you hinge your argument upon the lack of a proof of the means of some human ability simply points to flaws therein. >> in particular, the notions of Godel: that within any axiomatic system, th >> answers to some positable questions are indeterminable. > >You know, since you mentioned the book GEB, I thought you might have been >trying to bring Godel's Incompleteness Theorem into the discussion. But >since you didn't specifically state that, I wanted to give you the benefit >of the doubt. > >The Incompleteness Theorum if very useful for certain lines of reasoning. >And it might be relevant to the strong AI problem. But it has no relevance >to the compiler problem we've been discussing. > It is relevant to the notion that humans must use methods not algorithmic. >In the compilers "axiomatic system", it is not possible to even construct >the kind of questions to which GIT refers. > >The compiler is not burdened with proving that it is correct, or that its >own output is correct. At most we are asking it to select the more efficient >of several proposed solutions. This in some sense does involve a "proof", >but the required proof is no of the validity of the axioms (i.e., the >compiler algorithm), nor is it a proof that the "system" is self-consistent. > >> For all the nit-picky details of the works of these masters, the points they >> make are far grander. The real value of their works is not kept solely >> within the realm from which their conclusions emerge, but within which >> such conclusions find additional value. > >If you know where to apply them. You can't just willy-nilly claim that >GIT applies to any random problem. > This is one of the wonders of human intelligence: to make leaps of logic and application. >If you are going to maintain that GIT precludes compilers generating code >as efficient as the best human-generated code, you'd best be prepared to >present a logical argument as to why GIT applies. It's not a magic wand, >and I'm not going to concede your point at the mere mention of it. I am not applying GIT to the operation of compilers. Instead, I am applying it to the operation of human intelligence. Whether you concede the point makes no difference to me. My purpose is to refute your claims of the superiority of software versus human intelligence, and that is all. William R. Buckley

26 years, 11 months

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Tandem Boards Available - Vancouver BC

by mcquiggi＠sfu.ca

Hi Gang: I went on a trip to one of the local electronic/scrap stores today, and noted that they have about twenty CPU and other boards from some sort of Tandem machine for sale. They're marked $10 each (that's about $6.50 US) but one could probably haggle with success. Is anyone on the list into Tandem? There hasn't been any discussion of Tandem and their "non-stop" line (read as "full stop" for those with any hands-on experience with the machines) on the list at all, in my recollection. I'm not into Tandem either, but if anyone's interested I can call the store owner for further info this week. Kevin -- Kevin McQuiggin VE7ZD mcquiggi(a)sfu.ca

26 years, 11 months

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ABS - or is it Pure BS

by kaikal＠MICROSOFT.com

Boy, we're way off topic here. First off, most ABS will lock up if all four wheels slip. How's it to know that you haven't stopped? No variety of braking is going to help you on ice, only tires (e.g. Bridgestone Blizzak) help there. Secondly, ABS is for dry or wet roads. It actually increases stopping distance in snow and gravel, because on those surfaces it is more advantageous to lock up the wheels and pile up material in front of each tire. Kai -----Original Message----- From: Buck Savage [mailto:hhacker@home.com] Sent: Monday, April 05, 1999 3:20 PM To: Discussion re-collecting of classic computers Subject: ABS - or is it Pure BS >2) even if the ABS system fails it still works just like non-ABS brakes. unless >the vacuum (power assisted) system fails or the brake line is cut, or (very >unlikely) the piston sticks open, the brakes will work just fine. > ABS - American Bull Shi... I have noted one difficulty with ABS, and that is its failure to operate on snow and ice. Since I live in Southern California, I do not get that much snow but, in any quick application of my Mustang's breaks, on snow covered roads, they always seem to lock up. Well, the pumping action occurs but, at each application of the pump, I notice wheel lock-up. There is no stopping. William R. Buckley

26 years, 11 months

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IBM 5150 PC disk drive questions

by roblwill＠usaor.net

According to the jumper settings on the 5150, it appears that 4 floppy drives can be connected to the computer. How is this possible? I'm guessing 2 internal, and two external, but there's only one connector for an external drive, so it would only allow 3 drives. Or is there a special controller that has dual external ports? Any suggestions? ThAnX, -- -Jason Willgruber (roblwill(a)usaor.net) ICQ#: 1730318 <http://members.tripod.com/general_1>

26 years, 11 months

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homemade computer for fun and experience...

by edick＠idcomm.com

Fact is, the serial protocol for communicating with your 'AT keyboard is widely understood and well documented. I'm sure anyone who could program an older 8-bit micro could program a PIC or other single-chipper, like the 87C42 which I believe is still made, to do what the old 8042 does. If you get an 8742, I don't think they even have a code protection bit. Given that you have too much principle, and perhaps not enough interest, to replicate the 8042 ( a clever choice of chips ) you could simply decode the binary you do get from the keyboard with a lookup table. Dick -----Original Message----- From: Tony Duell <ard(a)p850ug1.demon.co.uk> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 04, 1999 6:31 PM Subject: Re: homemade computer for fun and experience... >> >> > True. But AFAIK the AT keyboard host interface was never implemented in >> > TTL (it always used a programmed 8042 microcontroller), so it's a little >> > harder to build from scratch. >> >> If what you're trying to do is interface the AT keyboard to some custom >> controller that doesn't need to be otherwise AT-compatible, there's no >> reason why you need the 8042. The AT keyboard interface is not particularly >> harder to implement than the XT interface was. I've written code for several >> products that bit-banged it on a microcontroller. > >Absolutely. BUT : if you are making a homebrew machine, the last things >you need are (a) I/O that's timing critical (at least not for the >keyboard) or (b) a microcontroller that you have to program and debug. > >And then, as you said below, the AT keyboard protocol is not that well >documented. The XT is a little better documented, if only because there's >a circuit using standard chips (plain TTL chips) that accepts XT keyboard >input. You can work out any odd bits of the protocol from that. > >Alas IBM never published the 8042 ROM source, so you can't use that as a >reference. > >> >> The AT keyboard interface protocol is really a pathetic design, though. It's > >I'll not argue with that. > >> a pain in the ass to deal with, and it's not well documented anywhere (even > >The documentation is not brilliant, but you can figure out how to talk to an >AT keyboard from the info in the TechRef if you have to. Not an ideal >first project, though. > >-tony >

26 years, 11 months

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microcode, compilers, and supercomputer architecture

by CLASSICCMP＠trailing-edge.com

> The problem now is, if I change the file that contains foo(), I have to >apply my patch again. Or in other words, once I patch the output from the >compiler, I can no longer use the compiler. If this is a one time shot and >I will only work with the output from then on, then no problem. But >otherwise ... > > -spc (Although from the discussion it seems that the deal was a one > shot anyway ... ) This sort of situation (compiler doesn't quite do what the writer wants) is actually widely encountered in some classic Unix kernels. There are parts of the kernel that need interlocking, running at a different priority, etc. The "classic" way of doing this is to compile the C code into assembly code, run a program that massages the assembly code to change the details of how some actions are done, and then assemble the modified code. As the old fortune cookie program says, "I'd rather write programs that write programs than write programs" :-). -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 11 months

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microcode, compilers, and supercomputer architecture

by hhacker＠home.com

>> Your argument, Eric, was that the microcode compiler generated code >> that is equally as efficient as that you, or someone else, could have >> constructed by hand. Megan in no way implies the use of assembly code. >> The microcode compiler would generate an object file, which by your >> own admission above, generated more code than could fit in the >> memory space available. You accepted her argument that the human >> was required to generate code more efficient than that produced by >> the microcode compiler. You protest _too loudly_ my friend. > Again, you used the word *assembly* and that implies my point. >No, I accepted her argument that for conventional machine code compiled from >a conventional high-level language, a human can fairly easily generate >better code. But if you had read my posting *carefully*, I specifically >protested that this is *not* the same problem as compiling horizontal >microcode from a specialty source language. > >I *still* stand by my statement. The compiler produced better code >in minutes than I could have produced in three months. Your argument seems >to be that a compiler can't produce better code than a human with an infinite >amount of time could. I'll concede you that point. Or maybe I won't. A >compiler with an infinite amount of time could have simply tried every possible >combination of control store bits (for the 512*72 example, 2^36864 >possibilities), and run a set of test vectors against each candidate to >determine which ones meet the specifications, and of those which yields >the highest overall performance. And by applying some relatively simple >heuristics, the number could be reduced from 2^36864 down to a number that, >while still huge, could at least be done during the remaining life of the >universe. But this is irrelevant, because neither the human nor the computer >has an infinite amount of time available. Halting problem (P vs NP) difficulties aside, I have never seen the situation in which the resultant output of a language translator could not be further optimised, with the exception of trivial cases. The value that you ascribe to your time, notwithstanding. >If my job had depended on finishing the project in question without using >the compiler, the only way to do it would have been to expand the control >store to 768 or 1024 words, because after spending a lot of time writing >microcode by hand, it would probably have been larger than 512 words. It is always easier for the human to find a wasteful application of resources to facilitate job completion than to hunker down and produce a quality and efficient product. Witness the ubiquitous supremacy of Windows, i.e. NT. >It was the use of the compiler that allowed me the luxury of shrinking it to >fit in the 512 words available. Without using the compiler, there is no way >in hell that I would have had time to do such a thing. You argument, again, is the value that you place on your time, and not the quality of your intellect. I maintain that the computer, no matter the skill of the algorithm, is always to fall short of human productivity. In this, I agree with such notable researchers as Roger Penrose and Douglas R. Hofstadter. Have you read Godel, Escher, and Bach: The Eternal Golden Braid? >It is instructive to note that when I was trying to squeeze the 514 words >down to 512, I discovered that the compiler had succeeded in combining >several things that I wouldn't have easily found, Here, again, you base your argument on your lack of skill and capacity, not on the limitations of algorithms. > because the compiler is >actually *better* at doing data flow analysis than I am. That's not because >the compiler is inherently more clever than I am, but because it is not >subject to the Hrair (sp?) limit as I am. It's not more clever, but it's >more tolerant With regard to self-deprication, you seem to hold the decathelon in tolerance. >of doing tedious recordkeeping and matching. Of course, if I >had the time to meticulously do the same thing, I obviously could do at least >as good a job of data flow analysis as the compiler. But in practice that's >simply not going to happen. Life's too short. I do accept that life is, indeed, too short. I, too, would not want to spend my life on a single problem, a single implementation of algorithm to the limits of optimality. That, however, is not the point. >Most everyone in this discussion is just parroting the conventional wisdom >that compilers don't generate code as compact or efficient as humans can, >without considering the possibility that for specific problems and under >specific constraints, they actually can be *better*. I'm absolutely willing >(and eager) to concede that in the general and unconstrained case, the >conventional wisdom holds true. Demonstrate a case where an algorithm provides a better solution to a translation problem, and I'll show you a case where the algorithm provides exactly the solution obtainable by a human but, no better a solution than that obtainable by a human. Your argument is that no human can perform the act of a computer, and this is shear lunacy. William R. Buckley

26 years, 11 months

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IBM PC disk drive questions

by roblwill＠usaor.net

According to the jumper settings on the 5150, it appears that 4 floppy drives can be connected to the computer. How is this possible? I'm guessing 2 internal, and two external, but there's only one connector for an external drive, so it would only allow 3 drives. Or is there a special controller that has dual external ports? Any suggestions? ThAnX, -- -Jason Willgruber (roblwill(a)usaor.net) ICQ#: 1730318 <http://members.tripod.com/general_1>

26 years, 11 months

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bringing up an 8f...

by geoffrob＠stmarks.pp.catholic.edu.au

-----Original Message----- From: Bill Sudbrink <bill(a)chipware.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Tuesday, 6 April 1999 00:55 Subject: RE: bringing up an 8f... >Not to mention that the Acrobat user interface _SUCKS_! Agreed. I'd be a darn sight happier with a simple text file, or even html. I can read that even on a Vax with a VT100 and Lynx. Acrobat is somewhat tedious to manipulate. And I hate having to zoom on text that's too small to read. Just my $0.02 worth as well. Cheers Geoff Roberts

26 years, 11 months

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microcode, compilers, and supercomputer architecture

by hhacker＠home.com

-----Original Message----- From: Eric Smith <eric(a)brouhaha.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 04, 1999 8:03 PM Subject: Re: microcode, compilers, and supercomputer architecture >Megan wrote: >> well put... I've yet to find a compiler which can produce code which >> could not then be further optimized in some way by a person well >> versed in that machine's architecture... > >Yes, but if you paid attention to the original claim, you would see that >I asserted that it was true for horizontal microcode with large amounts >of data dependency. This is *very* different than trying to compile C >(or Pascal, or Bliss, or whatever) for a typical architecture (which more >closely resembles vertical microcode). > >One of the systems I microcoded had 512 words of control store (of about >72 bits each), and running my microprogram source code through the compiler >produced 514 words of microinstructions. With about two weeks of >concentrated effort, I was able to eventually squeeze out two >microinstructions. Total development time: 6 weeks. > >If I had tried to write all of the microcode in "assembly", it would have taken >me longer to write, and it probably would have been *bigger* on the first >pass. And I still would have had to spend a lot of time on hand optimization. >I think this would have taken at least 12 weeks of development time, although >since I didn't do it that way I'll never know. And, from your most recent posting: >> Again, you used the word *assembly* and that implies my point. > >Now you've lost me completely. You were quoting your own writing, not >mine. I didn't even *mention* "assembly" in my posting, except in quoting >you. > >> Halting problem (P vs NP) difficulties aside,> Is this use of the word "assembly" not yours? I, sir, am quoting you, not me! > >I've never seen the situation in which human-generated code could not be >further optimized, with the exception of trivial cases. Your assertion >does not contradict my claims. Of course, this brings up the issue that >"trivial" is not objectively quantifiable. One could perhaps credibly argue >that a trivial code sequence is one for which no further optimization is >possible. I'm not taking that position, but simply pointing out the >difficulty in basing arguments on non-objective statements. > >In point of fact, I've seen huge amounts of human-generated code that was >nowhere near as optimal as code that a compiler would generate. > >All this proves is that neither humans nor compilers tend to produce >optimal code. It says nothing about which tends to produce more optimal >code. > The fact that an individual program is incapable of producing superior code, relative to optimality, only serves to indicate that humans suffer a greater degree of falability vis-a-vis the computer, which as you said is quite happy to act on tedium. That says nothing about the general case that humans have superior intellectual capacity vis-a-vis the computer. After all, who invented what? This discussion is founded upon your statement: >> Maximisation of processor throughput, and minimization of >> microinstruction count, is at least half the purpose of microprogramming. > >Sure. And the microcode compilers I've written and used are much better >at optimizing horizontal microcode than I have the time or patience to do >by hand. > >> For such optimisation to be effected, on must necessarily write directly >> in microcode, either bit and byte streams, or coded as in assembly >> languages. > >No, it doesn't. Microcode almost always has a lot of data dependencies, >which means that a compiler can often do as well as a human at optimizing >it. > And yet, you argue against yourself with: >... when I was trying to squeeze the 514 words down to 512, I ... Herein, you admit that your personal skills quite outweighed those of the algorithm that you constructed for the purpose of compiling a high-level code into a particular microcode. Recall: >Sure. And the microcode compilers I've written and used are much better >at optimizing horizontal microcode than I have the time or patience to do >by hand. Also, recall: >Therefore if I can use four weeks of my time to write a compiler and two weeks >to slightly tweak the output of that compiler ... So, we are agreed that a human has greater capacity for the preparation of optimal code. I conceed the notion of sufficient time to complete a task. What you have failed to address is that the human intellect is not limited by the capacity to algorithmatise a solution. Hence, P vs. NP, GEB, and in particular, the notions of Godel: that within any axiomatic system, the answers to some positable questions are indeterminable. Humans have the capacity to make judgements by means outside of those mathematical and logical, hence the reference to Penrose. For all the nit-picky details of the works of these masters, the points they make are far grander. The real value of their works is not kept solely within the realm >from which their conclusions emerge, but within which such conclusions find additional value. William R. Buckley

26 years, 11 months

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bringing up an 8f...

by jfoust＠threedee.com

At 12:46 AM 4/5/99 -0700, you wrote: > >Are you insane? The excrutiatingly slow and bloated Microsoft Word >screams compared to Acrobat. I get so antsy waiting for Acrobat to update >a fricken PDF page on the screen that my head wants to explode. I suspect it's like PostScript, or metafiles, or executable code in general: it all depends on what's generating the PDF file. Some PDFs are apparently just bitmaps, others a mix of text and bitmap, others just text. The existence of a PDF print driver doesn't mean what goes through it will be the best. - John

26 years, 11 months

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homemade computer for fun and experience...

by allisonp＠world.std.com

<IF you can stick the XT keyboard (are keyboards that talk that protocol <still being made?) then look at the circuit of the PC or XT. The keyboard <interface is a few TTL chips hung off an 8255. At keyboards can be used as well as they are similar (not the same). You'll have to make a interface as the serial is not compatable with UARTs, also you will have to convert the key down/Key up codes to something more human. <I'd make it modular (in that I'd have expansion slots), but I'd probably <put the CPU + RAM + basic I/O on the 'motherboard'. For prototyping, <DIN41612 connectors are easier than edge connectors because you don't <need special boards with the connector fingers on them. An acceptable bus is ISA-8bit and there are plenty of FDC, VIDEO, HDC cards for that bus that could easily interface to z80. <SRAM is a _lot_ easier. And now that 64K SRAM is 2 chips at most (62256's <are cheap now), I'd use that. DRAM is not too hard until you realise that <layout and decoupling are critical if you want to avoild random errors. Same comment, one proviso, if your doing over 256k consider DRAM and MMU. a good article for that is at the TCJ site. <[For the hardware wizards here : Yes you can homebrew with DRAM - I've <done it. But not as my first real project]. For a z80 system of 64 or 128k static is far easier. Also 128kx8 parts are cheap so even 256k or 512k ram systems are modest. Allison

26 years, 11 months

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Lisp, the machine language. Was Re: Hallelujah!

by hhacker＠home.com

>I was unclear. > >I meant that the microcode/assembly language words _corresponding to a >particular LISP program_ were created from that program and then executed. >If you define a function (like the ever-popular factorial function) >something has to be stored in memory as the definition; presumably it is >some sort of primitive (as in not-easily-decomposed) machine language, and >presumably there is a program that converts source text into object code. > >So wouldn't that converter be a compiler? I believe that a number of subtle >details happen during the conversion process, so you couldn't even say the >compiler is a simple compiler. > >-- Derek You were quite clear. The answer is no. Consider the instruction set of the x86. The MOV instruction is actually implemented as a small sequence of microinstructions. There is, in fact, no dedicated series of gates and other electronic aparatus which implements the operation of MOV. Instead, it is implemented as a series (or sequence) of smaller operations, such as LOAD REGISTER, ADD REGISTERS, etc. If you are not familiar with the processes of microprogramming, then you should become so. Microprograms are not stored in RAM. Instead, they are stored in ROM. Also, the only processors which today are founded upon the operation of dedicated electronics (that is, electronic circuits which implement fully and singly the operation of a machine instruction for a computer) are the RISC machines. This is why they are so bloody fast. All CISC machines are microprogrammed. For those who are aware of the operations of the HP 21MX processors, these are microprogrammed machines. As it happens, the user of such a computer can alter the microprogramming. This is the computer upon which I obtained my experience as a microprogrammer. I do not mean to say that the factorial function is microprogrammed. It is not. However, the operators CAR, CDR, CONS, etc. are implemented in microcode. Hence, there is no need for translation - they are executed directly. For confirmation of this, contact my friend, Chuck Fry at chucko(a)ptolemy.arc.nasa.gov Now, it is true that the printed text of the program must be converted to the instruction set of the computer but, the process is like this. "CAR" corresponds to the instruction with byte code 0x01 "CDR" corresponds to the instruction with byte code 0x02 and so on. Of course, the byte values I give are only examples. The true translations are not known to me. However, each operator of the Lisp language will correspond to a single instruction code of the Lisp machine. This is a far cry from the result one usually obtains from a compiler. If a compiler were used by a Lisp machine, then the operation of CAR would involve the production of dozens of machine instructions, just as the call of a subroutine in C involves dozens of machine instructions. Heck, a simple addition in C results in an instruction sequence like MOV AX, address of data1 ADD AX, address of data2 MOV address of result, AX For the Lisp machine, CAR would result in an instruction like CAR address of source operand list, address of result operand list William R. Buckley

26 years, 11 months

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Lisp, the machine language. Was Re: Hallelujah!

by hhacker＠home.com

>> Consider the PDP 11/44 in my living room. It is constructed using the >> AMD 2900 series of bit-slice microprocessor chips. In this case, the > >Well, I've never seen a PDP11 processor (as opposed to a floating point >processor or a VAX) that uses 2900 series. IIRC the 11/44 uses 74S181 >ALUs and a sequencer built from TTL (and maybe some 82S100 PLAs) > >-tony > Not mine. I just pulled the processor card and it contain 16 of the AM2901BDC chips, copyright 1978. The card has designation M7093 imprinted in the PCB metalisation layer. Well, upon closer inspection this seems to be the FPP. The card designated M7094 does have four of the 74181 type chips, and this is probably the general purpose CPU component. Any way, the point that I was trying to make is that the control code for the 2901 was contained in ROM, and not so much that the CPU was implemented via the 2901. Lets concentrate on the issue, not the errors associated with making the point. William R. Buckley

26 years, 11 months

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homemade computer for fun and experience...

by edick＠idcomm.com

Well . . . I did think one could get two short cards on one S-100. I did have something concrete in mind, too. If one inserts a wire-wrap 62 pin (8-bit ISA) connector into a DIN 41612 right-angle socket, such as what one finds on a VME wire-wrap board, but of opposite gender, (remembering that I once sold S-100 wire-wrap boards with a pattern certainly suitable for this purpose, and VME wire-wrap cards as well) one can, indeed, host two 8-bit ISA cards on a single s-100 board. This would certainly be cheap enough in most cases, to warrant such an effort. The software might get to be a problem, though. Dick -----Original Message----- From: CLASSICCMP(a)trailing-edge.com <CLASSICCMP(a)trailing-edge.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Saturday, April 03, 1999 6:58 PM Subject: Re: homemade computer for fun and experience... >>What might be fun would be an S-100 card to serve as an interface to a >>Monochrome/Hercules equivalent card and an IBM-style keyboard > >Compupro did a similart thing over a decade ago ... it's called the "PC Video" >S-100 card. > >>thrift store. That would save the hassle of having an extra keyboard and >>monitor for your "extra" PC. > >I dunno - to me the most useful possible console interface is a serial >port. I can hook a terminal up, I can hook a VAX up, I can hook a >PC-clone up, etc. > >-- > Tim Shoppa Email: shoppa(a)trailing-edge.com > Trailing Edge Technology WWW: http://www.trailing-edge.com/ > 7328 Bradley Blvd Voice: 301-767-5917 > Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 11 months

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bringing up an 8f...

by CLASSICCMP＠trailing-edge.com

>> Are you insane? The excrutiatingly slow and bloated Microsoft Word >> screams compared to Acrobat. I get so antsy waiting for Acrobat to update >> a fricken PDF page on the screen that my head wants to explode. >> >> Unless you have the latest and greatest 500Mhz PII wonder machine, Acrobat >> is a farce. >Not to mention that the Acrobat user interface _SUCKS_! There are several alternatives to Acrobat. I'm quite familiar with them because there are no Acrobat binaries for any of the architectures that I commonly use. 1. Any Ghostscript release from the past few years does PDF quite nicely. You have a choice of a command line interface (very useful for doing batch conversions from PDF to something more usable) or a point-and-drool shell ("GhostView", aka "gv"). Ghostscript is available for many platforms, it is independent of any specific windowing system, and it is quite usable on platforms which lack graphic displays at all. For details, see http://www.cs.wisc.edu/~ghost/ 2. XPDF, which only does PDF (unlike Ghostscript which does postscript as well) and only can display on X-windows screens, is also available. See http://www.foolabs.com/xpdf/ Personally, I think Postscript is a better "high-level" approach to describing page layout than PDF is, but I also understand the commercial reasons that force Adobe to push PDF instead. I've been having a blast lately doing my own printed circuit board layout in Postscript, incidentally :-). Bezier splines, here we come! -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 11 months

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bringing up an 8f...

by allisonp＠world.std.com

This is why I'm positng about progress. I'm well above average with tools, test gear, spare parts and debug skills. I seriously wonder how many of the "I want a SROCTH because I've heard they are neat(kewl, cool, gnarly...)." have the skills or the clues to even power it successfully. These things are as far from PCs as one gets. The end result is destruction rather than preservation. OH, "SROCTH" is Some Rare Old Computer To Hack. Part of the power supply work was removing and repairing an existing bungled hack that had some of the foil burnt off the board, likely with some soldering torch of killer proportions. When dealing with old power supplies like this substitutions are not a good thing. <Great progress! The stuck bit won't be hard to find/fix. I had a couple of <bad TTL chips when debugging the 8/f here, they were easy to find. Similar <problem (always-off bit in certain I/O operations). I will find it but first back to the power supply as the -15V folded. <Let us know how your core plane works! Initial tests indicate it was good, I was able to run a simple 5 instruction program. Short story. The core in this one came from an 8E that had two 8k stacks I got from the Mill in '85 and gave away in 90 or 91 to another Digit (digit=person that works/worked at Digital). It was known good when given away. <Schematics and other info's on highgate (when you get time to download the <viewer!). There is no free or shareware viewer for that format I can find. If you have one it can likely save the file as jpg of gif. Why an oddball version of TIFF was used is beyond me. Allison

26 years, 11 months

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bringing up an 8f...

by emu＠ecubics.com

Hi, ---------- > From: CLASSICCMP(a)trailing-edge.com > To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> > Subject: RE: bringing up an 8f... > Date: Monday, April 05, 1999 9:33 AM > I've been having a blast lately doing my own printed circuit board layout > in Postscript, incidentally :-). Bezier splines, here we come! But even then, having a layout in postscript for refrerence reasons is nice. A quad qbus board doesn't fit on a letter format, but a "resize to fit" do, what is really nice, if you try to document some rewiring.. cheers, emanuel

26 years, 11 months

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PDF vs Postscript, was Re: bringing up an 8f...

by emu＠ecubics.com

Hi, ---------- > From: Zane H. Healy <healyzh(a)aracnet.com> > To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> > Subject: Re: bringing up an 8f... > Date: Sunday, April 04, 1999 8:18 PM > > Actually I'm of the opinion that PDF is just about the best format out > there for documenation, although I know there are a LOT of people that > disagree with that. I prefer postscript. There are many tools to view the stuff, print it, or change. Most of the time i like to print the documents, but i always reformat them. (something like 2 pages on one pages, landscape format , duplex print) simply not to waste so much paper. only my .002 $ cheers, emanuel

26 years, 11 months

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Sickening Documentation

by healyzh＠aracnet.com

I got the Base Set of OpenVMS 7.2 doc's that I ordered today. How disgusting! On the spine, it says "Compaq OpenVMS", and the spines are ALL white, so they aren't colour coded by type. Oddly two of them are the old Digital manuals from the 7.1 release. I don't mind the "Compaq" where the "digital" used to be, it's the "Compaq OpenVMS" I find sick! How egotistical! Oh, well, I've got doc's that match the version I'm running now at least (though the V5 "System Managers Manual" will continue to be the most used manual). Now if the two Cluster manuals that I ordered at the same time would ship, I'd be almost happy. Still need up-to-date DECnet manuals though. Zane (Axiously waiting for the V2 Hobbyist CD's to be ready) | Zane H. Healy | UNIX Systems Adminstrator | | healyzh(a)aracnet.com (primary) | Linux Enthusiast | | healyzh(a)holonet.net (alternate) | Classic Computer Collector | +----------------------------------+----------------------------+ | Empire of the Petal Throne and Traveller Role Playing, | | and Zane's Computer Museum. | | http://www.dragonfire.net/~healyzh/ |

26 years, 11 months

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A IIgs keyboard is a?

by PB14＠leicester.ac.uk

On 31 Mar 99 at 18:18, Mike Ford wrote: > M0487 Small, no function or direction keys, and indents on both sides of > the rear where the ADB plugs are. Sorry, no IIgs handy at work to check the part number. However... The M0487 is the model which first shipped with the Mac Classic and LC. It is is the successor to the M0116 which was supplied with the SE series (the M0116 again has no function keys but the frame surrounding the keys is rectangular and generally more conventional in shape). Phil ************************************************************** Phil Beesley -- Computer Officer -- Distributed Systems Suppport University of Leicester Tel (0)116 252-2231 E-Mail pb14(a)le.ac.uk

26 years, 11 months

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homemade computer for fun and experience...

by allisonp＠world.std.com

<I seriously doubt, however, that anyone has written an article about <mounting two ISA cards on an S-100 board which occupies only a single card Form factor is of little meaning and actially in many cases pointless. However I'd already done it using 8bit ISA cards and for many it's trivial if DMA is not required. Allison

26 years, 11 months

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Probably OT: Copy-Rite duplicating machine

by roblwill＠usaor.net

Hi! I know this is probably off-topic, but I figured that someone here may be able to give me a bit of info on this thing. Today my church gave me this old copy machine (Is mimeograph the proper word for it?). I've figured out how to load the paper and turn it on, but that seems to be all. I put the paper in the one side, drop the loading rollers, push down a lever on the other side, some sort of liquid squirts out of a reservoir onto a roller, the paper gets pulled through, and comes out the other side (the side with the lever) into another tray, and is damp (from whatever squirted on to the roller). On the side where the paper comes out, there's a large aluminum roller with a slot in it. I've seen things like these used in movies (I think), and on that roller is what looks like a piece of carbon paper. If so, how does it work? Now the questions: - What is the liquid in the reservoir? It looks and smells like alcohol (sort of - it's been sitting in there for about 20 years) - What type of ink (if any) would it use, and where would I find this ink? - Where does the thing (document - whatever) go that I would want to copy? I think that's all the questions that I have for now. Please reply to me privately (don't want to take up the list's bandwidth). I'd like to get this thing working, since it's in pretty good shape, appears to function, and still has the original dust cover :) ThAnX, -- -Jason Willgruber (roblwill(a)usaor.net) ICQ#: 1730318 <http://members.tripod.com/general_1>

26 years, 11 months

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Lisp, the machine language. Was Re: Hallelujah!

by hhacker＠home.com

>> Consider the instruction set of the x86. The MOV instruction is actually >> implemented as a small sequence of microinstructions. There is, in fact, >> no dedicated series of gates and other electronic aparatus which >> implements the operation of MOV. Instead, it is implemented as a >> series (or sequence) of smaller operations, such as LOAD REGISTER, >> ADD REGISTERS, etc. If you are not familiar with the processes of >> microprogramming, then you should become so. Microprograms are >> not stored in RAM. Instead, they are stored in ROM. > >Microprograms can be stored in RAM. It may not be common to have a 'soft >microcodes' processor (one where the microcode is stored in volatile >memory and loaded when the machine boots), but they exist. I can see 3 >from where I am sitting (2 PERQs and a Xerox Daybreak). > >If you think of a normal machine code instruction, then there are several >steps that have to be performed to execute that instruction and fetch the >next one. You can represent that process either as a collection of random >logic, or as a state machine with one flip-flop per machine state (which >is how the Philips P850 does it), or as a program. The last is >essentially what microcode is. > >> For those who are aware of the operations of the HP 21MX processors, >> these are microprogrammed machines. As it happens, the user of >> such a computer can alter the microprogramming. This is the computer > >In other words the microcode is partially stored in RAM on this machine. > >> Now, it is true that the printed text of the program must be converted to >> the instruction set of the computer but, the process is like this. >> >> "CAR" corresponds to the instruction with byte code 0x01 >> "CDR" corresponds to the instruction with byte code 0x02 >> >> and so on. Of course, the byte values I give are only examples. The >> true translations are not known to me. However, each operator of >> the Lisp language will correspond to a single instruction code of the >> Lisp machine. > > >There is a problem here. The process of programming in Lisp is >essentially defining new functions. So either _all_ of these are stored >in microcode (which would require a very large control store) or more >likely (and I happen to know that the PERQ Spice LISP does it this way), >there are some 'core' functions (like CAR, CDR, CONS, etc) that are >implemented as microcode, and higher level functions, including ones >defined by the user are defined in terms of these (and other higher level >functions). > >In which case, the program that translates a user definition into the >calls to both microcode and 'machine code' functions is pretty similar to >a normal Lisp implementation running on a micro (many of which do not >compile all user input to the machine code of the CPU they happen to run >on). It's dubious whether you call that an interpretter or a compiler, >though. > >-tony > Of course, I over simplified the discussion but, only to get my point across. Sure, it is possible for the microcode to be in RAM. The IBM 370's were just such machines. More than once, while I was an operator of such computers, the service representative came to the site, opened a panel on the operator console, and changed the 5 1/4" floppy disk. By doing so, he changed the microprogram of the computer. This microprogram was loaded each time the computer was powered on. For the x86 however, the microcode is hardcoded into the chip. My wish is for a computer system that provides for dynamically modifiable microcode, so that my self-modifying programs could obtain a new level of self-modifyability! As for the Lisp difficulties, remember, it takes only a few of the basic operators to define the language. All else can be derived from same, and AFAIK is derived from same. So, there is no need to implement derivable functions in microcode. William R. Buckley

26 years, 11 months

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microcode, compilers, and supercomputer architecture

by hhacker＠home.com

>Megan wrote: >> well put... I've yet to find a compiler which can produce code which >> could not then be further optimized in some way by a person well >> versed in that machine's architecture... > >Yes, but if you paid attention to the original claim, you would see that >I asserted that it was true for horizontal microcode with large amounts >of data dependency. This is *very* different than trying to compile C >(or Pascal, or Bliss, or whatever) for a typical architecture (which more >closely resembles vertical microcode). > >One of the systems I microcoded had 512 words of control store (of about >72 bits each), and running my microprogram source code through the compiler >produced 514 words of microinstructions. With about two weeks of >concentrated effort, I was able to eventually squeeze out two >microinstructions. Total development time: 6 weeks. > >If I had tried to write all of the microcode in "assembly", it would have taken >me longer to write, and it probably would have been *bigger* on the first >pass. And I still would have had to spend a lot of time on hand optimization. >I think this would have taken at least 12 weeks of development time, although >since I didn't do it that way I'll never know. Your argument, Eric, was that the microcode compiler generated code that is equally as efficient as that you, or someone else, could have constructed by hand. Megan in no way implies the use of assembly code. The microcode compiler would generate an object file, which by your own admission above, generated more code than could fit in the memory space available. You accepted her argument that the human was required to generate code more efficient than that produced by the microcode compiler. You protest _too loudly_ my friend. William R. Buckley

26 years, 11 months

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homemade computer for fun and experience...

by edick＠idcomm.com

DIN41612 connectors are the type used in Multibus-II, VME and SUN, MAC-II's NuBus, etc. They have a matrix of 3 rows of 32 holes in the socket, of which you can buy connectors which only have the outer rows populated. This means that there remain 64 holes, 62 of which would be occupied by a wire-wrap (2-level) ISA-8-bit connector. This would allow placement of the "daughter" board close to the S-100 board's surface and permit fitting it into a single slot of the S-100, provided the end-plate were removed. They can be had in either straight or right-angle versions, though the right-angle normally sits on the circuit card while the straight versions are mounted to the backplane. That's why I suggested that the gender would have to be reversed. Dick -----Original Message----- From: Dave Dameron <ddameron(a)earthlink.net> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 04, 1999 10:13 PM Subject: Re: homemade computer for fun and experience... >Hi all, >At 10:52 PM 4/3/99 -0700, you wrote: >>Well . . . I did think one could get two short cards on one S-100. I did >>have something concrete in mind, too. If one inserts a wire-wrap 62 pin >>(8-bit ISA) connector into a DIN 41612 right-angle socket >>> >What do DIN 41612 connectors look like? >-Dave >

26 years, 11 months

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Fwd: older computer stuffs

by bluoval＠mindspring.com

>from a post in alt.forsale: original poster is: c-bristol(a)usa.net (LA., CA) *** OLD COMPUTER EQUIP. NOT IBM STYLE, UNIX PDP-11, VIC20******** DOCUMENTATION: SOFTWARE: UNIX: full sets of docs for v.6, v.7, 4.1BSD, 4.2BSD, 4.3BSD, SUN OS2, SUN OS3, SunView. About 3 big file boxes of UNIX docs. Also have distribution tape of v.7 for PDP-11 licensed to me from SCO (Santa Cruz Operation) and the PDP11 hardware it is licensed for. I paid $1350 to SCO for this licence and tape, forsale now Cheap! Original v6 Lyons course, 1978?. Bell SysV Driver writing course, 1985. DOCUMENTATION: SOFTWARE: DEC OS: Heathkit H-11 paper tape operating system, papertape media and docs, new, as shipped from Heathkit. DOCUMENTATION: SOFTWARE: DEC OSs: Full set, RT-11 v2, v3, v4, partial RSX-11. Also have the software on floppy and RK05, and the PDP-11's that are licensed to run it. Also Heathkit H-11 paper tape operating system, media and docs, new. Also a couple of RSTS/E manuals. Disks also (RX01, RL01,RK05). RT-11 set, XXDP Diagnostics, on 8" RX01 floppies and paper tape.MOSTLY SOLD DOCUMENTATION: SOFTWARE: DEC OSs: Full set, RT-11 v2, v3, v4, partial RSX-11. Also have the software on floppy and RK05, and the PDP-11's that are licensed to run it. Cheap! MOSTLY SOLD DOCUMENTATION: HARDWARE: many DEC PDP-11 docs from 1970-1985 on microfiche. (Have reader too.) MOSTLY SOLD

26 years, 11 months

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Is this normal? ODT Question

by cmcmanis＠mcmanis.com

So I've got a Q-bus system with 64KW (128KB) of RAM that is allegedly an 18 bit backplane. When I'm in ODT I can type: @177770/ And enter values for 1777772, 1777774, 1777776, and then it wraps around to 000000. If I start at 200000 it works until 3777777 and then wraps to 2000000. So it seems to not cross a 64KB boundary. Also the boot area is 177300 ? so it is in the upper 4K of the 64KB address space, is it legal to have memory "above" the I/O page? --Chuck

26 years, 11 months

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microcode, compilers, and supercomputer architecture

by hhacker＠home.com

>> It is clearly the case that automated mechanisms are >> inferior to a quality human intelligence. For anyone to think otherwise >> is to relegate decisions of life to a computer program. > >We don't need to bring moralizing into the discussion. Most of us already >relegate a lot of life's decisions, including some life-critical ones, to >computers every day. > >Or are you the kind of person that refuses to buy cars with antilock brake >systems? Use of such systems does not imply that I fail to recognise their limitations. William R. Buckley

26 years, 11 months

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[Fwd: FREE Computers - Especially for collectors! (AUS)]

by djenner＠halcyon.com

Heads up for you down under. -------- Original Message -------- Subject: FREE Computers - Especially for collectors! (AUS) Date: 5 Apr 99 02:48:51 -0900 From: "Lazy Bone" <zhulien(a)alphalink.com.au> Organization: Badly Configured Clients, Inc. Newsgroups: alphalink.forsale,comp.os.cpm I have the following computers to give away if you collect them ASAP - otherwise I will throw them away: - Panther 128, 2 x 5.25" FDD, 6502 based, 128kb RAM? - TRS80 MC10 (appears complete) - TRS80 COCO - TRS80 COCO2 - CAT - Spectravideo SV318, Keyboard, Manual - Spectravideo SV328, Keyboard, Manual, SV601 Expander, 5.25" FDD (SV902), Cassette (SV903), CP/M 2.2... - SONY Hitbit HB75B MSX - Peach (Hitatchi MB6890) & software - Atari 800XL - Spectrum+ (needs keyboard replacement) & software - Apple 2e, 5.25" FDD, various expansion cards - Apple 2e clone, 5.25" FDD - BBC ModelB, Builtin modem & ROM, Colour Monitor, 2 x 5.25" FDD - Sinclair QL (Telecom ComputerPhone), 2 x microdrives - Microbee model 2, seikosha printer - Microbee model 2 - VZ300 - VZ300 (faulty?) - Sega Master System - Sega Master System 2 - Sega Megadrive 2 - Nintendo NES - Sinclair ZX81 in original box missing cables Since I picked up 40 or so computers from a friend today who is going abroad, I cannot keep the above because of lack of space. If you want to collect anything, please ring me ASAP on 03 98131630. Julian

26 years, 11 months

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11/73->RL02 Final

by jpl15＠netcom.com

Well. Over forty messages spawned from this topic. I am very most certainly grateful to each of you who has taken your time and expertise to add knowledge to the subject. I am not going to pursue the 11/73 any longer, because it is hardly a DEC machine, anyway (physically at any rate) and because I think that I would be better served by putting the resources into my 11/44. I have two 11/23s which *are* true-DEC, and perhaps these can be made to hold aloft the LSI banner in my collection. I definately want the 11/73 for the data on it's HD, tho. This leaves the 11/43a system and the uVAX II to be made to speak RL02, and then there's some form of networking between them, and also to a contemplated 486 or 586 platform dedicated to one of the PDP11 emulators. To this machine I can then install my SCSI 9trk drive, and do real handy things like CDROM and Media Conversion. I know the PR1ME 2550 has an ethernet port on it, and a SCSI port, and it has a Kennedy 9100 native to it... Sigh. I have an appointment with a friend of mine who is an electrician, to get an estimate on re-working my pitiful sixties-era house wiring. If I squeeze every drop out of the taxes this year, it might just pay for the sub-panel and the conduit run to the Machines. Yup. I got it *bad*... Thanks again everyone. I am going to take stock of my DEC module situation and then put some things up for trade... I'm angling for an RL02 on the uVAX... hint hint hint. Ah, damn.. forgot about the MINCs.... Cheerz John

26 years, 11 months

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homemade computer for fun and experience...

by CLASSICCMP＠trailing-edge.com

> Why restrict yourself to PC-clone keyboards? May as well just put a > serial console port on and ... >Because, as I have traced around countless motherboards of all >kinds and found this is far easier to cobble up one using keyboard, >KB controller stolen from old motherboard, than trying to design >and build a parallel KB or design an i/o and needed codes for >terminal. "Designing an I/O and needed codes for a terminal" is dead simple. Put in a UART, put in TTL to RS232 or 20mA level translators, and you're done. Want to output a letter in the console? OUT 00H. Want to input a character? INP 00H. Come on guys, I'm *not* trying to be difficult. I'm pointing out that a serial console interface is: 1. Universal. No need to find a particular keyboard design or a particular monitor scan rate and/or interface. 2. Easy to build - it's just a UART hooked to an I/O port. 3. Easy to program - heck, with many UART's you get interrupt-driven input and output for free. And no need to write a terminal emulator! 4. Doesn't take up valuable memory space like memory-mapped video. 5. Gives enormous interfacing flexibility. You can hook it to a terminal, you can hook it to a ASR-33, you can hook it to your PC-clone, you can put a modem on it and dial into it. You're in fat city. In brief, it's the option that gives you the most advantages with the least effort. A no-brainer! > I have heard horror stories from some who did the parallel > kbs and they're no longer made. I could be mistaken. And I think folks who build video generators will run across the same problem in the future. The computer will easily outlast several generations of monitors and keyboards, and you want to be able to still use it in 20 years, don't you? I can use my 24-year-old S-100 boxes with serial console interfaces just fine today, just as I can use my 30-year old PDP-8 with anything that has a serial interface, and I expect that I'll be able to use them 30 years from now. Do you think you'll be able to buy new VGA (much less EGA) monitors 20 years from now? Heck, the FCC has an executive order that NTSC television will be gone and replaced by HDTV in less than a decade - better start buying up composite-input monitors now while they're still out there! -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 11 months

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Lisp, the machine language. Was Re: Hallelujah!

by hhacker＠home.com

>> computers, the service representative came to the site, opened a panel >> on the operator console, and changed the 5 1/4" floppy disk. By doing > >I think I read somewhere that the 8" floppy was originally designed for >this purpose. This may be. Yet, this was my introduction to the 5 1/4" format. At the time, I worked for Remex, a division of EX-CEL-O corporation, and they made 8" and 5 1/4" inch drives. The year, IIRC, was 1977. William R. Buckley

26 years, 11 months

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RLV11/RL02 ->11/73?

by CLASSICCMP＠trailing-edge.com

>>The field guide claims at its top: >> >>*This list may always be found on sunsite.unc.edu, in the following >>*directory: >>*/pub/academic/computer-science/history/pdp-11/hardware/field-guide.txt >But for how long will sunsite.unc.edu resolve to metalab.unc.edu? Probably forever :-). Still, I should fix it up with the new "sanitized" name. It was only a few weeks ago that I thoroughly replaced my "triumf.ca" address on the web pages there... -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 11 months

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Hallelujah!

by allisonp＠world.std.com

16megs is the minimum to run W95 in my experience and it runs much better with 32m. It's a pig. <My P200 machine, when with only 32 meg, swapped itself to pieces it seemed <after a few days since a reboot even though I'd shut down all unused apps <to run one. System resources still were not released. After kicking up to <64 meg I now can go for several weeks until needing a restart to recover. It's called memory leaks. Seems some applications do not return resources to the pool as do some win95 drivers. often it can be tracked to one bad driver. And to think my uVAXII is still running with the 9meg that I used to service a half dozen users plus network activity. Allison

26 years, 11 months

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homemade computer for fun and experience...

by edick＠idcomm.com

Again, I have to agree about the "waste-of-trees" nature of most "technical" documents these days. Nevertheless, I find it easier to understand the result of a SPICE simulation when displayed graphically, e.g. with PROBE as supplied with PSpice, as opposed to a 2-page long list of raw values. It's true, SOME terminals, more recently than when I last bought one, but nevertheless SOME terminals, were capable of graphic display. They just weren't up to what a PC could do unless you paid more than what a PC would cost. I already stated that the "old" machines did the "old" and in many instances quite persistent tasks well, and still would, given a chance. People have learned, however, that it's not as beneficial to have OLD hardware as to have new, not because of what it will do, but what it won't. I don't mean that it won't break. Any hardware can fail. It's a statistical reality. However, if you try to repair that old, fine, terminal you bought in the '80's you'll find you can't get it fixed for less than the cost of a PC. If, however, you break your PC, there's really nothing you can't repair or replace for much less than the cost of the original. Dick -----Original Message----- From: Tony Duell <ard(a)p850ug1.demon.co.uk> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 04, 1999 6:31 PM Subject: Re: homemade computer for fun and experience... >> What's happened over the years, however, is that people, having seen what a >> computer CAN do as shown in games, etc, have actually found ways to make >> data easier to interpret, and perhaps to add meaning and emphasis to a >> presentation, making it more persuasive, if not more informative, by using >> the graphical capabilities of a computer. > >Odd... I much prefer text to graphics for just about everything. Sure I >like circuit diagrams. And graphs, of course. But I find the typical '4 >colour glossy' that passes for a technical document these days to be a >waste of trees. I'd much rather sit down with an informative piece of text. > >> If you use a terminal, that's what you've got. There were, for a time, >> attempts made at graphic terminals. These failed, however, because there > >AFAIK X-terminals are still in use.... > >> weren't standards on which they could base their usage. Consequently, if >> one didn't have certain hardware, there were limitations on the software he >> could use. Today, that's not the case, as EVERYONE has a PC clone with at >> least 1Kx768 pixels in 256 or more colors. EVERYONE has fairly ample > >Do they? I don't. My PC has Hercules and CGA graphics only. I don't own a >VGA card (I might have an EGA card somewhere, but I don't use it). > >> Today, no one would normally consider a CP/M box for "useful" and essential > >Depends on the 'useful work'. I've done seriously useful work on a Z80 >machine in the last year or so (admittedly running LS-DOS and not CP/M). It >depends on what you class as 'useful work'. My old 8-bitters can still >talk to the special interfaces I've designed to (e.g.) test cabling, dump >ROMs, etc. Sure, I could use a PC. But have you tried getting the same >level of docs for a PC-clone as I have for my TRS-80 Model 4? The latter >is much easier to repair and keep running > >-tony > >

26 years, 11 months

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homemade computer for fun and experience...

by CLASSICCMP＠trailing-edge.com

>The goal: 8 bit or 16bit, running from ROM's for software and store >work files on HD, tape or floppy, text based on 6845 IC or similar. >That is beggining, in the end should able to run CPM or something. >I prefer to interface the PC keyboards to it as by make up the >convertor to something that cpu understands by microcontroller or >like. Why restrict yourself to PC-clone keyboards? May as well just put a serial port on it, that way you can use just about any terminal with it and won't restrict yourself to specific hardware. >I have so many TTL's and LSI's and some VLSI's, CPU's of all >kinds (intel, Zilog and others), memories, different crystrals and >oscillators. Should it be single board with everything on it in >stages or do it modular via cards? A CP/M-capable computer doesn't have to be very big at all these days - there are several commercially available designs/kits/boards which are a single PC board with just a couple of chips. The comp.os.cpm FAQ gives links to several of these designs. If I were you, I wouldn't restrict myself to what's in the junk box. Total semiconductor price for a CP/M capable computer can be kept to well under $25 using new parts. If I were doing it, I'd go surface mount, just to see if I could do it in under 2 square inches :-). -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 11 months

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homemade computer for fun and experience...

by CLASSICCMP＠trailing-edge.com

>Keep in mind, folks, that some of us remember when there simply weren't >computers which we could use. Back when I was a boy, even the US GOV >couldn't afford a computer capable of what my smallest simplest Windows9x >system is capable. The fact that I don't use it for pure number-crunching >is a recognition that there are other things equally deserving of the >benefits of advancing technology. If a picture is worth a thousand words, >then why type them if it's easier to draw the graphic representation. >Moreover, if you have to read my 1000 words (about a page) and then draw >yourself a graphic representation to understand and digest it anyway, why >not stick to the graphic? A simple graphic can save both ends of a >communication time, effort, and embarassment from when there's a >miscommunication. And a graphic display is a sure way to make certain that a human is necessary at every step of processing, making it difficult to impossible to automate many tasks. You can't search images for the occurence of a particular object. Graphics are the first step to the point-and-drool interface you find on just about every computer these days, where quality of presentation is emphasized over quality of content. -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 11 months

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Lisp, the machine language. Was Re: Hallelujah!

by hhacker＠home.com

>"Buck Savage" <hhacker(a)home.com> wrote: >> Actually, microcode is not compiled. > >All the microcode I've ever written was compiled. Of course, it was >compiled from special source languages defined for that explicit purpose. >No one with any sense would write a non-trivial amount of microcode any >other way. > >> The i860 is a single chip implementation of the Cray-1, > >No, it isn't. Don't believe all the marketing hype you read; those guys are >paid to lie their asses off. The architecture isn't even *close* to that of >the Cray-1. In particular, the i860 is not a vector processor. It is a >primitive superscalar processor, with a lot of the pipeline exposed to the >programmer. It is tough to write a good compiler for it. > >> and provides just about the same throughput as the Cray-1. > >Almost, for some things. But not for heavily vectorizable problems. For the HP 21MX, microcode looks like assembly language, so any tool used for translation purposes is, by definition, not a compiler. It may be that compilable languages are defined for the purpose of providing for microcode but, that would mean that the sequence of microinstructions is generally not predictable from the source code of the program thus translated. Maximisation of processor throughput, and minimization of microinstruction count, is at least half the purpose of microprogramming. For such optimisation to be effected, on must necessarily write directly in microcode, either bit and byte streams, or coded as in assembly languages. In any case, the use of a language translator always results in a reduction of process throughput. Recall that microcode involves the establishment of timing signals at critical control points within electronic circuits and, the selection of data paths within those circuits. Given this fact, there seems little reason to leave the efficiency of microcode up to the accuracy of a language translator, which we all know to be generally less accurate that the results obtained by a skilled human programmer. I would be grateful to learn from you of the tools you used in the preparation of microcode. All of the work I did was in graduate school in the early 90's, and to date I have not seen a single job made available to a microprogrammer type. I would really love to have an opportunity to perform this kind of work as a job function. As for the i860, sure, it is not actually the equal of a Cray-1 but, the architecture is equal to that of the processor section of the Cray-1. The chief difference in capacity lies in the memory architecture and other support hardware, all of which is external to the processor. The literature with which I am familiar regarding the Cray-1 states that it can perform two multiplies, involving four different operand, at a single machine clock cycle, and this is exactly the capability of the i860. Further, I should like to know in what ways you deem the Cray-1 to differ from the i860, particularly with regard to the processor section. Have you actually used the i860?

26 years, 11 months

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Emulating classic terminals

by CLASSICCMP＠trailing-edge.com

> Well, maybe it's donator's remorse, but I gave away my VT100's and 220's a > long time ago. I never had any strong feelings about ANSI terminals, having > lived without them for so long. On the other hand, I've lived with them for decades, and couldn't imagine being without them. They're the bread and butter of being able to interface with a wide variety of software on a wide variety of platforms! >What I would use is one of the simple display terminal routines available in >the public domain. There are plenty of them which emulate ANSI terminals if >that's what's wanted. And 99.9% of them are lousy. (In large part because the current generation of VT100 emulator writers have never even seen a real VT100, much less actually read the VT100 spec.) For a comparison of many products, both commercial and freeware, using an excellent test suite called "vttest", take a look at http://www.columbia.edu/kermit/k95compare.html Another very excellent resource on the subject is at Rick Shuford's web site, http://www.cs.utk.edu/~shuford/terminal/ -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 11 months

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homemade computer for fun and experience...

by edick＠idcomm.com

This is a sad but true artifact of the GUI. The best PC/Win95 backup program I have trips all over itself because it wants a human response to a query about whether or not to backup a file created by the backup program. It's not a BIG file, and it doesn't hurt having it there, nor would it hurt if it were left out. The default, however, and you can't get away from that, is to ask. I surely wish that were the only such case. Dick -----Original Message----- From: CLASSICCMP(a)trailing-edge.com <CLASSICCMP(a)trailing-edge.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 04, 1999 5:50 PM Subject: Re: homemade computer for fun and experience... >>Keep in mind, folks, that some of us remember when there simply weren't <snip> >>miscommunication. > >And a graphic display is a sure way to make certain that a human is >necessary at every step of processing, making it difficult to impossible >to automate many tasks. You can't search images for the occurence >of a particular object. Graphics are the first step to the point-and-drool >interface you find on just about every computer these days, where quality of >presentation is emphasized over quality of content. > >-- > Tim Shoppa Email: shoppa(a)trailing-edge.com > Trailing Edge Technology WWW: http://www.trailing-edge.com/ > 7328 Bradley Blvd Voice: 301-767-5917 > Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 11 months

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bringing up an 8f...

by allisonp＠world.std.com

<I've got the 8/e frontpanel prints here. From what I remember the 8/f is <a little different. The displays are leds (minor change around that part), otherwise it's identical to the 8e. <THe frontpanel display logic is mostly built from diode transmission <gates - this circuit < <In---->|-----+-----|<------+--- Lamp driver < | | <Sel-\/\/-----+ | < | <>From other gates-----------+ <for that lamp Does not compute based on the chip part numbers. <The MD inputs have their own set of gates. I'd start by tracing from MD1 <(pin AL1) through the diodes to the appropriate 380 lamp driver <(E26/6,7,2 on the 8/e). My guess is an open-circuit diode... Ther are very few diodes and the drivers appear to be 7404s with 74l54s used as selectors. Restate the problem... The display is the variable 12bit on off the rotary switch and only occures when MD is selected. This suggests the data selector logic or it's particular source on the board as MD on the bus has the correct data. <Oh, these old machines are quite easy to work on (famous last words...) Generally the PDP-8 series is fairly straightforward. Allison

26 years, 11 months

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homemade computer for fun and experience...

by edick＠idcomm.com

Well, maybe it's donator's remorse, but I gave away my VT100's and 220's a long time ago. I never had any strong feelings about ANSI terminals, having lived without them for so long. What I would use is one of the simple display terminal routines available in the public domain. There are plenty of them which emulate ANSI terminals if that's what's wanted. Just an ADM-3A or HAZELTINE-1500-equivalent function set would be adequate. Building in enhancements over what was done back when the computer was new would not be my goal. I'm always into exploiting the fact that these machines were once, and, hence, can still be, useful. I'd emphasize that the computers we use today, fast and fancy though they may be, don't really process text in a word processing vein much better than they could 20 years ago. Likewise, if it rolled out the payroll in accordance with both laws and schedules, it would probably still do that today. Dick -----Original Message----- From: Allison J Parent <allisonp(a)world.std.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 04, 1999 5:27 PM Subject: Re: homemade computer for fun and experience... ><Admittedly, many folks seem to believe that a computer must have ><a video generator to be a "computer". > >Retrorevisionist PCism. Though a VC8E is a definate computer thing. > >< My CP/M experience started with ><Model 33 Teletypes and blinkenlights front panels, so perhaps I'm the odd m ><out here. > >Same here. It's seems silly for me to recreate the logic and programming >of my vt100 when I have a vt100 that works better than any I could put >together. There is advantages to useing a PC keyboard and monitor as they >already take space on my desk but then again I can provide a serial port >and use the PC for a terminal. > >Allison >

26 years, 11 months

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homemade computer for fun and experience...

by edick＠idcomm.com

I have some reservations about your opeing assertion. I'd modify it to say that articles are sometimes descriptions of circuits that work, sometimes. I know people who build a circuit and try it once. If it works they say they have the circuit working, and if it doesn't, they only say they have it built. There are fellows I know who seem to be quite competent at building circuits, yet I see their stuff working and I see it malfunctioning, both. Sometimes I believe their circuits/assembly techniues to be solid, sometimes not. If I'm interested in applying a technology demonstrated in this manner, I often try it myself, sometimes simulating it first, if I have doubts about the validity of the underlying theory. The fact that a circuit LOOKS good doesn't excuse you from performing the requisite analysis. I've seen more error committed on the basis of inadequate analysis than probably any other reason. I seriously doubt, however, that anyone has written an article about mounting two ISA cards on an S-100 board which occupies only a single card slot when finished. That's what I was describing. I believe that's what is needed, as opposed, say, to a multi-board interface, occupying, say, the last position in a cardcage, thereby allowing cards to protrude somewhat beyond the end of the cardcage. I'd consider that a believable approach. The reason I say this is that the only way one gets to the notion I described is by ordering the DIN 41612 connectors with their genders reversed. Only a true dummy (referring to ME, of course) would do such a silly thing. I've got a basement full of circuits which didn't work though they were copied from the application note. There are also a number which do work, but I mostly delivered the working ones to someone who paid for them. Dick -----Original Message----- From: Allison J Parent <allisonp(a)world.std.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 04, 1999 5:27 PM Subject: Re: homemade computer for fun and experience... ><>Been there and done that. ><>Also, there are no less than two articles on how to go from s100 to ISA. ><> ><There's a substantial reach from an article to a solid and working circuit ><on a board capable of actually supporting the functions. This is > >The articles actually are descriptions of circuits that do work. > ><particularly true since, now, the user is required to understand the inner ><workings of his own machine as well as those of the card he wishes to use. ><Having the usual inkling about ISA is not always sufficient. > >That was true then. Unlike PCs with plug and pray configuring a s100 >system meant you generally had knowledge and documentation or were plain >crazy. > ><><ISA cards on a single s-100 board. This would certainly be cheap enough ><><most cases, to warrant such an effort. The software might get to be a ><><problem, though. >< ><Yes, and therein lies the "problem" for the average user. > >define average user... today that's mom and pop that buy a PC and plug >it in. Definatly not the case in 1980. The reality of older computers >like the S100, SS50, Multibus types were you had to be a knowledgeable >user. Or if that was a problem you went to Apple or TRS80 styled machine >where the hardware was generally a fixed and software was the experimental >arena. > >Allison >

26 years, 11 months

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homemade computer for fun and experience...

by edick＠idcomm.com

You're right on the money, here. It depends almost entirely on what your goals are or may be. ( Perhaps, like many of us, you don't know, exactly, what your goal(s) at any given time might be.) I try to fool myself into thinking that I do things involving computers and circuits to enhance/extemd my ability to earn a living. Maybe that's true. However, using a task like implementing a current strategy or algorithm on an old piece of hardware tends to extend one's thinking, which is also of benefit to one's ability to earn a living. If I had the task of building a homebrew computer, I could probably fit the whole thing on a single or maybe dual-width VME card. That's not much more area than an S-100 board if you leave out the regulators. The way this would have to come about, is that I'd build a processor<=>memory interface and an interface to a bridge controller for mass storage. If the processor didn't have I/O on board, which most of the ones in which I have interest relating to building a system from scratch do, then a single high-speed link to a system which had conventional resources would come next. Over time, I'd migrate the mass storage interfaces into my computer and leave out the bridge adapter. Likewise the external comm link(S). After that, it's anyone's guess. It depends on what goal(s) I am chasing at the time. Dick -----Original Message----- From: Allison J Parent <allisonp(a)world.std.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 04, 1999 5:26 PM Subject: Re: homemade computer for fun and experience... ><I'd thought of that, but if you're not careful, your 'homebrew computer' ><contains ready-built I/O cards only. That's no so educational as building ><them yourself. > >Depends on what your goals are. For me building yet another serial or disk >card is tedious and repetition. I'd rather experiment with advaced software >on old style but enhanced platforms. > ><Sure. But the IIRC, this thread started with somebody wanting to make ><their first homebrew machine. IMHO, this should be a fairly simple ><machine - say a Z80 + maximum of 64K memory. Adding lots more memory, ><MMU, etc can come later. The first machine should be something that is ><likely to work first time. > >No arguement. As a first pass machine static is usually the least painful >to deal with as are simple serial IO. The usual first time builder wants >more than their skills can generally support. > >Allison >

26 years, 11 months

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homemade computer for fun and experience...

by edick＠idcomm.com

Well, I'm inclined to agree with you. I've long felt that if one needed to spend time playing games, what was really needed was another job. What's happened over the years, however, is that people, having seen what a computer CAN do as shown in games, etc, have actually found ways to make data easier to interpret, and perhaps to add meaning and emphasis to a presentation, making it more persuasive, if not more informative, by using the graphical capabilities of a computer. As for the terminal vis-a-vie the color graphic display, I find the terminal quite limiting. However, most of the stuff I do is unaffected by these limitations. It's just the drafting work that would be limited, and perhaps the interpretation of the results from the various simulators I use. However, since I've got a farly hot system with which to do the drafting, the CP/M box doesn't really need graphics, does it? If you use a terminal, that's what you've got. There were, for a time, attempts made at graphic terminals. These failed, however, because there weren't standards on which they could base their usage. Consequently, if one didn't have certain hardware, there were limitations on the software he could use. Today, that's not the case, as EVERYONE has a PC clone with at least 1Kx768 pixels in 256 or more colors. EVERYONE has fairly ample resources, comparable, perhaps, to the sum of all the computer resources in the world when I went to college. Today, no one would normally consider a CP/M box for "useful" and essential work. For mental masturbation, speculation about would could, would, or should (note the subjunctive) have been, CP/M works just fine. If you have a construction business, or a medical office, there's no reason why CP/M can't work today every bit as well as it did back 20 or more years ago. However, aside from the notion of operating on an "antique" there's no reason to do so. It does serve to keep one grounded in what has changed over the years and what hasn't. Dick -----Original Message----- From: CLASSICCMP(a)trailing-edge.com <CLASSICCMP(a)trailing-edge.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 04, 1999 12:58 PM Subject: Re: homemade computer for fun and experience... >><ISA cards on a single s-100 board. This would certainly be cheap enough i >><most cases, to warrant such an effort. The software might get to be a >><problem, though. > >>Yes, and therein lies the "problem" for the average user. > >This is why I prefer simple serial console. No software to write, >no memory mapped video to take a chunk out of usable memory, no >memory banking schemes, no dependence on finding monitors of a >particular scan rate or interface. Just a simple I/O port! > >Admittedly, many folks seem to believe that a computer must have >a video generator to be a "computer". My CP/M experience started with >Model 33 Teletypes and blinkenlights front panels, so perhaps I'm the odd man >out here. > >-- > Tim Shoppa Email: shoppa(a)trailing-edge.com > Trailing Edge Technology WWW: http://www.trailing-edge.com/ > 7328 Bradley Blvd Voice: 301-767-5917 > Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 11 months

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homemade computer for fun and experience...

by edick＠idcomm.com

Keep in mind, folks, that some of us remember when there simply weren't computers which we could use. Back when I was a boy, even the US GOV couldn't afford a computer capable of what my smallest simplest Windows9x system is capable. The fact that I don't use it for pure number-crunching is a recognition that there are other things equally deserving of the benefits of advancing technology. If a picture is worth a thousand words, then why type them if it's easier to draw the graphic representation. Moreover, if you have to read my 1000 words (about a page) and then draw yourself a graphic representation to understand and digest it anyway, why not stick to the graphic? A simple graphic can save both ends of a communication time, effort, and embarassment from when there's a miscommunication. If you tend to use your hands when you're explaining something, you probably know what I mean. Dick -----Original Message----- From: jpero(a)cgocable.net <jpero(a)cgocable.net> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 04, 1999 5:03 PM Subject: Re: homemade computer for fun and experience... >Date sent: Sun, 4 Apr 1999 16:23:49 -0600 >Send reply to: classiccmp(a)u.washington.edu >From: "Richard Erlacher" <edick(a)idcomm.com> >To: "Discussion re-collecting of classic computers" <classiccmp(a)u.washington.edu> >Subject: Re: homemade computer for fun and experience... >Originally to: <classiccmp(a)u.washington.edu> > >> Well, I'm inclined to agree with you. I've long felt that if one needed >> to spend time playing games, what was really needed was another job. >> >> What's happened over the years, however, is that people, having seen what >> a computer CAN do as shown in games, etc, have actually found ways to make >> data easier to interpret, and perhaps to add meaning and emphasis to a >> presentation, making it more persuasive, if not more informative, by using >> the graphical capabilities of a computer. > >Beauiful point and to point that out, we're still doing it even way >back from stone and clubs days. Graphics on any media is easier >to understand than stackful of numbers and words even spoken! >Even when I was in elementery and HS school we generate >numbers and words into graphics respentions or vice vesa. That >was in CP/M to 386 days but didn't use computers. > >> >> As for the terminal vis-a-vie the color graphic display, I find the >> terminal quite limiting. However, most of the stuff I do is unaffected by > >Terminal is out because one would have to code so much that you >really made another i/o out of software. I'm at that mental stage >now. Better start in hardware then put bit of homebrew s/w in to >get started. > >> Today, no one would normally consider a CP/M box for "useful" and >> essential work. For mental masturbation, speculation about would could, >> would, or should (note the subjunctive) have been, CP/M works just fine. >> If you have a construction business, or a medical office, there's no >> reason why CP/M can't work today every bit as well as it did back 20 or >> more years ago. However, aside from the notion of operating on an >> "antique" there's no reason to do so. It does serve to keep one grounded >> in what has changed over the years and what hasn't. > >We're still writing characters/numbers and users are using so >powerful computers *because* it's easier for them to see in >graphics form and graphics items to operate at or in to get basic >functions done besides writing and putting numbers in. That eat up >more power just to do that. Crunching numbers and doing massive >moves in graphics, is one thing I accept. And, decent windowing >that does quickly and low on resources requirements does get job >done bit easier that about it as I know so far. > >> Dick >> >Wizard

26 years, 11 months

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Lisp, the machine language. Was Re: Hallelujah!

by allisonp＠world.std.com

<Yes, although you could consider "P-code" to be a lower level. It is lower level. <> But why would anyone want something that was microcoded to run Pascal? < <Speed mostly, that and ease of use with compilers. P-code is not Pascal. It's a platform that all Pascal P-compilers grind code to. Speed wise it was slow as the Pcode was interpreted on all but the WD Pascal microengine. Why was it done? In the late 70s Pascal was emerging as a teaching language and it was highly standardized. Most small systems had the resources to run it as native compiled but the authors (UCSD) decided that portable Pcode would allow more platforms to run it as the Pengine was easier to code than a whole compiler. The additional part was the P-system was an integrated system with all the tools (all written in pascal) for editing, compiling and running programs. It was a good teaching environment as it isolated the user form the machine very well. the entire environment was menu driven and integrated. I have a NS* that runs the z80 version. Allison

26 years, 11 months

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bringing up an 8f...

by allisonp＠world.std.com

<trouble with it also, but can peal it apart. So basically you're stuck <having to read it using Windows, which quite bluntly strikes me as stupid, I have winders and the problem is I have to buy the dang viewer...Not me. Fortunately having worked with 741, 744 and 7441 power supply and regulators this (740) is not too strange for me. Allison

26 years, 11 months

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bringing up an 8f...

by allisonp＠world.std.com

<> OH, "SROCTH" is Some Rare Old Computer To Hack. < <I can name a number of people here who easily have enough clues to keep Clearly I'm not refering to them. <I am, however, a little worried with what happens to some of the machines <sold on E-bay. I suspect that some of them go to people who want them but <haven't a clue how to look after them. That is the exact audience I refer to. <Ouch!. It's bad enough when a fault causes melted PCB traces (Some SMPSUs <suffer from this). This was abuser installed. I've cleaned it up a lot. The current bug fixed in the PS was the chopper shorted and then fried the SCR used for crowbar. We are up again. Now back to the stuck bit. Allison

26 years, 11 months

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homemade computer for fun and experience...

by allisonp＠world.std.com

<Admittedly, many folks seem to believe that a computer must have <a video generator to be a "computer". Retrorevisionist PCism. Though a VC8E is a definate computer thing. < My CP/M experience started with <Model 33 Teletypes and blinkenlights front panels, so perhaps I'm the odd m <out here. Same here. It's seems silly for me to recreate the logic and programming of my vt100 when I have a vt100 that works better than any I could put together. There is advantages to useing a PC keyboard and monitor as they already take space on my desk but then again I can provide a serial port and use the PC for a terminal. Allison

26 years, 11 months

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homemade computer for fun and experience...

by allisonp＠world.std.com

<>Been there and done that. <>Also, there are no less than two articles on how to go from s100 to ISA. <> <There's a substantial reach from an article to a solid and working circuit <on a board capable of actually supporting the functions. This is The articles actually are descriptions of circuits that do work. <particularly true since, now, the user is required to understand the inner <workings of his own machine as well as those of the card he wishes to use. <Having the usual inkling about ISA is not always sufficient. That was true then. Unlike PCs with plug and pray configuring a s100 system meant you generally had knowledge and documentation or were plain crazy. <><ISA cards on a single s-100 board. This would certainly be cheap enough <><most cases, to warrant such an effort. The software might get to be a <><problem, though. < <Yes, and therein lies the "problem" for the average user. define average user... today that's mom and pop that buy a PC and plug it in. Definatly not the case in 1980. The reality of older computers like the S100, SS50, Multibus types were you had to be a knowledgeable user. Or if that was a problem you went to Apple or TRS80 styled machine where the hardware was generally a fixed and software was the experimental arena. Allison

26 years, 11 months

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Lisp, the machine language. Was Re: Hallelujah!

by allisonp＠world.std.com

<C-machines (and I wouldn't class Unix as being one, although Unix would <ran rather well _on_ one) have existed as well. They're machines where <the instruction set is optimised for running C (so things like pointer <indirection, particular loop structures, etc are machine <instructions/operations). the PDP-11 instruction set was the near ideal C machine due to it's available addressing modes. Allison

26 years, 11 months

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homemade computer for fun and experience...

by allisonp＠world.std.com

<I'd thought of that, but if you're not careful, your 'homebrew computer' <contains ready-built I/O cards only. That's no so educational as building <them yourself. Depends on what your goals are. For me building yet another serial or disk card is tedious and repetition. I'd rather experiment with advaced software on old style but enhanced platforms. <Sure. But the IIRC, this thread started with somebody wanting to make <their first homebrew machine. IMHO, this should be a fairly simple <machine - say a Z80 + maximum of 64K memory. Adding lots more memory, <MMU, etc can come later. The first machine should be something that is <likely to work first time. No arguement. As a first pass machine static is usually the least painful to deal with as are simple serial IO. The usual first time builder wants more than their skills can generally support. Allison

26 years, 11 months

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Lisp, the machine language. Was Re: Hallelujah!

by hhacker＠home.com

>On Sun, 4 Apr 1999, Buck Savage wrote: >>not stored in RAM. Instead, they are stored in ROM. > >AFAIK, they are hard-coded into the CPU (except for PERQ and the like >where they can be altered). ROM conjures up images of little socketed >chips on the motherboard. > >--Max Eskin (max82(a)surfree.com) > Consider the PDP 11/44 in my living room. It is constructed using the AMD 2900 series of bit-slice microprocessor chips. In this case, the microcode is, in fact, stored in ROM chips, each of which is socketed to the motherboard. For some other types of processors, sure, the CPU real estate does carry the code but, the part of the chip that holds the code is ROM. William R. Buckley

26 years, 11 months

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Several things

by mark_k＠iname.com

Hi, Several different subjects in one message... Sony 650MB 5.25" MO drive ------------------------- I posted about this drive a couple of week ago. At the time, I thought one of the firmware EPROMs was faulty. (It wasn't. I have backed up all four EPROMs in the drive.) It turned out that the drive lens needed cleaning. Not having a 5.25" head cleaning disk -- these are expensive, I think IBM wants over 50 pounds for one -- I had to disassemble the drive, removing both circuit boards to reveal the lens. After cleaning with a cotton wool bud & isopropyl alcohol and putting the drive back together, it miraculously worked! The surfaces of all the disks were quite dirty. I believe the drive was used in the City of London, and years of pollution left a residue on the surfaces. I don't have a 5.25" MO disk cleaning kit, but luckily it's quite simple to clean 5.25" disks by hand. Briefly, I did this: - wear plastic gloves to avoid getting oil from skin on surface - breath on disk surface and wipe radially with a folded-up kitchen towel - rotate the disk using finger (there is space to do this between the outside of the disc and the casing) and repeat the breath & wipe until the entire surface is cleaned - do the same for the other side Things I learned: - Old MO drives and disks are sometimes available very cheaply, so it's worth looking out for them. - Cleaning the drive lens and disk surfaces can bring performance back to as- new. Dirt impairing performance might be a common reason why a company would get rid of old drives. - You don't need an expensive cleaning kit to clean 5.25" disks. If you're adventurous, you can clean the drive lens without needing to buy a special disk. - The old drives are much slower than modern ones. Performance is about equivalent to a 4.5x CD-ROM drive for reading, with average seek time of 95ms (some modern drives are 20-25ms). If anyone in the UK wants to get rid of an old 5.25" MO drive, especially a 1.3GB unit, please let me know. I'd like to have a backup unit in case my drive breaks down. EPROMs ------ My experience with one of the firmware EPROMs (made by TI) in the Sony drive showed that "not all EPROMs are the same", which is news to me at least. Data in most EPROMs can be dumped by doing this: - drive /OE low - set up address lines - read value on data bus However the TI EPROM didn't like that; doing it that way, even reading multiple times and ANDing the results, gave errors. After changing my program to set up the address lines before driving /OE low, everything went okay. Now I need to re-dump the various EPROMs from other things that I thought were bad. Hopefully at least some will be okay. C= PET VisiCalc EPROM --------------------- The Commodore PET version of the VisiCalc spreadsheet came with a chip that plugged into a socket on the main board. This was probably an EPROM, used for copy-protection. I have an original VisiCalc package, minus this EPROM. Does anyone know where I can download an image of the EPROM from? Nutspinner ---------- Disassembling PCB-mounting D-type connectors is a pain without having a nutspinner for the hexagonal bolt things which typically fix the connector to a panel. What size, number or whatever nutspinner is the right one for this purpose? IBM 3363 WORM drive ------------------- Along with the Sony MO drive, I picked up an IBM model 3363 WORM drive (IBM part number 63X4146). This was made in 1987. The original product announcement can be read on the IBM web site. It uses write-once disks which store about 200MB. Luckily it came with twelve such disks, four of which are still in their wrapping. Anyway, the drive uses some kind of custom interface. It connects to a special ISA or MCA card via a cable with 37-way D connectors at each end. The drive came with two MCA cards, part number 63X4266. I have been unable to test the drive or cards, since I don't have an MCA machine. Does anyone know what the part number of the ISA controller for the 3363 drive was? And where I might get one (cheaply)? The MCA controllers have a firmware (EP)ROM on. One uses a 27C64 EPROM, which I was able to backup without (many) problems. The other uses what I presume is a mask ROM, MN2364DSP; this is made by Matsushita. I can't seem to dump this properly, so its pinout must be somehow different to the 2764 EPROM. Any ideas where I might look to find the pinout for this chip? Regards, -- Mark

26 years, 11 months

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RLV11/RL02 ->11/73?

by CLASSICCMP＠trailing-edge.com

>> Generally, a "D" at the front means it's some sort of communications >> option, a "M" means memory, a "K" means CPU, "R" means disk controller, >> a "T" means a tape controller, an "A" means an A/D or D/A converter, >> a "V" means some sort of video-related hardware, and "L" means either >> a line printer or a linear module. I'm sure someone will come up >> with many options that don't quite fit into this scheme :-). >Obvious exceptions without even thinking about it : I don't think they're all obvious exceptions, though some are certainly pushing the definitions to their limits! >DR11-x (parallel interfaces, not really comms) "Yeah but" a very common use of these cards were for interprocessor communications (not necesarily between two -11's.) In any event, a parallel interface is conceptually not much different than a serial one, though certainly by the time you start putting interrupt request and DMA handshaking on the cable you are stretching the boundary of what "comms" is. >KMC11 (soft-microprogrammed version of the DMC11. Not really a processor) DEC felt differently - they really pushed the fact that there was a processor (they call it a "microprocessor", somewhat at odds with the modern interpretation, but it makes historical sense) in there. >KM11 (maintenance card, not a processor) >KW11-x (time clocks, etc) Well, the module designation has to start with some letter, and I think K is more appropriate than anything else here. >KL11 (early version of the DL11, current loop serial at 110 baud) If used as the console interface - as the KL11's usually were - K isn't too inappropriate. >MNCxx (MINC I/O modules, not memory at all) >LPS11 (Lab Peripheral System, not a printer interface) These are, indeed, true exceptions - though I don't think anyone would get too confused and try to use a MINC module in place of memory :-). -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 11 months

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homemade computer for fun and experience...

by edick＠idcomm.com

OOPS! I thought you were referring to the ubiquitous "text mode" switch on the back of so many EGA-class monitors, e.g. NEC Multisync-I, of which I've pressed several into service for Win95 with VGA cards. These use analog inputs and really aren't much different from VGA monitors, with the exception of their default horizontal sweep rate. Dick -----Original Message----- From: Tony Duell <ard(a)p850ug1.demon.co.uk> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 04, 1999 4:09 PM Subject: Re: homemade computer for fun and experience... >> >> You're right. The "text" mode was really not a valid construct for VGA > >Eh? Text mode has nothing really to do with the monitor. It means that a >single character cell on the screen is controlled by 2 bytes of memory. >One contains the character code (Ascii + a lot more characters), the >other contains the attributes (foreground/background colours, etc) > >> valuable. The "hardware" text mode with which I'm familiar is simply a >> color killer, which drives the display into a light green on a dark green > >Text mode can be (and is, on CGA and EGA and probably VGA) a colour mode. > >-tony >

26 years, 11 months

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bringing up an 8f...

by mbg＠world.std.com

>Things must be dry before power up or electrolisys and other bad things >happen. Pure water is generally harmless. In what way harmless? Even 'pure' water has ions... (or so I've learned in chem class) >Soap, I used one of the standard products that seems to work well on >glasses. You mean something with a surfactant? Megan Gentry Former RT-11 Developer +--------------------------------+-------------------------------------+ | Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com | | Unix Support Engineering Group | (home): mbg!world.std.com | | Compaq Computer Corporation | addresses need '@' in place of '!' | | 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ | | Nashua, NH 03062 | "pdp-11 programmer - some assembler | | (603) 884 1055 | required." - mbg | +--------------------------------+-------------------------------------+

26 years, 11 months

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Lisp, the machine language. Was Re: Hallelujah!

by hhacker＠home.com

>> "Buck Savage" <hhacker(a)home.com> wrote: >> > Actually, microcode is not compiled. >> >> All the microcode I've ever written was compiled. Of course, it was >> compiled from special source languages defined for that explicit purpose. >> No one with any sense would write a non-trivial amount of microcode any >> other way. > >All the microcode I've ever written (or seen) was written in a special >_assembly_ language. Or at least I'd class it as that as (a) one 'line' >of microcode corresponded to one microinstruction and (b) the language >statements were pretty close to the hardware definition. > >Here's a PERQ microinstruction : > >R0:=R0+R1, if neq goto(loop); > >The first 'phrase' defines the contents of >X and Y fields (select particular registers) >AMUX, BMUX fields (gate registers to ALU inputs, rather than, say gating >a constant there) >ALU field (do an addition operation) >W field (we want to write it back to a register and not just set the flags) > >The second phrase sets the >Condition field (to select the 'not equal' condition) >Jump field (to do a got and not just a next instruction, say) >SF and Z fields (to define the jump address). > >So the actual machine instruction is pretty close to the higher level >version. OK, some fields (Z in particular) can be set by several >different types of phrase, as the Z field is used for jump addresses and >IO addresses and shifter control and constants and... Yes the assembler >moans if you try to set it in 2 different ways in the same instruction. > >-tony > This is my experience as well. HP 21MX microcode is very similar. I will dig up some examples and post it at a later time. Thanks, Tony, for the examples and the clarification. William R. Buckley

26 years, 11 months

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Lisp, the machine language. Was Re: Hallelujah!

by hhacker＠home.com

>On Sun, 4 Apr 1999, Chuck McManis wrote: > >>They are micro-coded to run LISP, sorta like the WD P-Engine machines run >>PASCAL. > >So, an assembly language program for them would look like lisp, as opposed >to MOVs, ADDs, and so forth? And same with Pascal? But why would anyone >want something that was microcoded to run Pascal? Are there any other >languages that have gotten microcoded into a processor? > > --Max Eskin (max82(a)surfree.com) > The value of a high-level language capable machine is that the code can run without the need to invoke language translation. In such cases, the hardware becomes a language interpreter, with the speed of processing dramatically increased. For a well designed system, the speed of processing is actually greater for a Lisp program running on a Lisp machine than it would be for the same Lisp program to run on a non-Lisp machine CISC or RISC processor. William R. Buckley

26 years, 11 months

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homemade computer for fun and experience...

by edick＠idcomm.com

You're right. The "text" mode was really not a valid construct for VGA monitors. Many EGA monitors would work just as well as VGA's, which, I guess is a testament to the not so unusual notion that people charge less for a product even though they've spend extra resources to make it less valuable. The "hardware" text mode with which I'm familiar is simply a color killer, which drives the display into a light green on a dark green background. It didn't do anything to the sync. Monitors which work with VGA should be fine. What's required in order to make the VGA look like monochrome, is either to drive all the colors equally or to drive only the green video. It would be much simpler to allow the use of an S-100 adapter to use his old monochrome monitor with either a mono or a Hercules, or whatever other card he desires. His software will have to deal with it anyway, and the hardware for mapping it isn't too complicated to support on an adapter card. Dick -----Original Message----- From: Tony Duell <ard(a)p850ug1.demon.co.uk> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 04, 1999 12:13 PM Subject: Re: homemade computer for fun and experience... >> Fire). One of those little switch boxes would serve just fine. The 8.0 MHz >> Z80 wouldn't be sufficient to drive a VGA, so no need for anything fancy. > >Hmm... Don't VGA cards still have a hardware text mode? That's all you >really need for the Z80 machine, and using it wouldn't be any worse than >using an MDA or CGA card, once it's initialised. > >Of course that means you need to get a VGA card based on a documented >chipset so you do know what to stick in all the registers. The on-board >BIOS is going to be no use at all. > >I've seen a VGA card in a 4.77MHz 8088 machine, and it was usable for >text and point-plotting type graphics. I think a Z80 could manage that as >well. Of course you'd probably need some kind of paging hardware to map >all the VGA's memory space into the Z80 memory map. > >The advantage of using a VGA card is that most people have a VGA monitor >on their desk anyway... > >-tony >

26 years, 11 months

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FA: ZWS-0200-97 pair and ZWS-0300-04 Units "SupersPORT" portables on eBay

by rhblake＠bigfoot.com

Not sure if anyone may be interested but I have just posted these two ZDS machines to eBay as well as a GridCase2 (see the other auctions link)

26 years, 11 months

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Apple stuff....

by roblwill＠usaor.net

Will do. -- -Jason Willgruber (roblwill(a)usaor.net) ICQ#: 1730318 <http://members.tripod.com/general_1> -----Original Message----- From: Mike Ford <mikeford(a)netwiz.net> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 04, 1999 3:15 AM Subject: Re: Apple stuff.... > >I bought a box full of Apple etc. cables recently, wait a couple days and I >will sort out what I have and put it on my web page. > >http://www.netwiz.net/~mikeford/MacList.html > > >

26 years, 11 months

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Several things

by CLASSICCMP＠trailing-edge.com

>C= PET VisiCalc EPROM >--------------------- >The Commodore PET version of the VisiCalc spreadsheet came with a chip that >plugged into a socket on the main board. This was probably an EPROM, used for >copy-protection. I have an original VisiCalc package, minus this EPROM. Does >anyone know where I can download an image of the EPROM from? I'd be interested to know exactly what this chip did. It was never perfectly clear to me that it was used for copy-protection. >Nutspinner >---------- >Disassembling PCB-mounting D-type connectors is a pain without having a >nutspinner for the hexagonal bolt things which typically fix the connector to >a panel. What size, number or whatever nutspinner is the right one for this >purpose? 3/16 inch. -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 11 months

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Lisp, the machine language. Was Re: Hallelujah!

by allisonp＠world.std.com

<>They are micro-coded to run LISP, sorta like the WD P-Engine machines run <>PASCAL. < <So, an assembly language program for them would look like lisp, as opposed <to MOVs, ADDs, and so forth? And same with Pascal? But why would anyone <want something that was microcoded to run Pascal? Are there any other <languages that have gotten microcoded into a processor? Pascal was never microcoded, the P-interpreter was microcoded on one system. The difference is significant. The P-engine was a theorhetical stack machine that Pascal would optimally compile to. The idea was everything above the P-engine level would be standard code and only the P-engine would ahve to be rewritten for each different processor (which is why it was on PDP-11, Z80, 6502 to name a few). Allison

26 years, 11 months

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homemade computer for fun and experience...

by CLASSICCMP＠trailing-edge.com

><ISA cards on a single s-100 board. This would certainly be cheap enough i ><most cases, to warrant such an effort. The software might get to be a ><problem, though. >Yes, and therein lies the "problem" for the average user. This is why I prefer simple serial console. No software to write, no memory mapped video to take a chunk out of usable memory, no memory banking schemes, no dependence on finding monitors of a particular scan rate or interface. Just a simple I/O port! Admittedly, many folks seem to believe that a computer must have a video generator to be a "computer". My CP/M experience started with Model 33 Teletypes and blinkenlights front panels, so perhaps I'm the odd man out here. -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 11 months

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homemade computer for fun and experience...

by edick＠idcomm.com

please see imbedded comments below. Dick -----Original Message----- From: Allison J Parent <allisonp(a)world.std.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 04, 1999 11:47 AM Subject: Re: homemade computer for fun and experience... ><have something concrete in mind, too. If one inserts a wire-wrap 62 pin ><(8-bit ISA) connector into a DIN 41612 right-angle socket, such as what on ><finds on a VME wire-wrap board, but of opposite gender, (remembering that ><once sold S-100 wire-wrap boards with a pattern certainly suitable for thi ><purpose, and VME wire-wrap cards as well) one can, indeed, host two 8-bit > >Been there and done that. >Also, there are no less than two articles on how to go from s100 to ISA. > There's a substantial reach from an article to a solid and working circuit on a board capable of actually supporting the functions. This is particularly true since, now, the user is required to understand the inner workings of his own machine as well as those of the card he wishes to use. Having the usual inkling about ISA is not always sufficient. ><ISA cards on a single s-100 board. This would certainly be cheap enough i ><most cases, to warrant such an effort. The software might get to be a ><problem, though. Yes, and therein lies the "problem" for the average user. >What software problem... since s100 cards tend to be all different anyway >it would be the norm that software would have to be created. > >Allison >

26 years, 11 months

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RLV11/RL02 ->11/73?

by allisonp＠world.std.com

<I've done it useing a RLV12 board set though. As far as I know it can't b <done with the RLV11 you have. At least I was given to understand that if <you try you'll let out the magic smoke. I'e done it with both using the correct backplanes. As I remember the SMS1000 is a bit strange in the boot deperatment. <If you're wanting to boot off of RL02's then remember that you'll want to <have something with boot roms that support the drives. The only thing I <have that does is a /23+ My 11/73 boots RL02 (both unix V7 and RT11). Allison

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test-drb