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

by kylevowen＠gmail.com

I am writing my master's thesis on accelerated life testing and would like to get a collection of parts to decap and experiment on. What prompted my study is a failed 7474 dual flip-flop in a PDP-8/E. As I later read (on here, I believe) was that the 7474s seem to fail in higher number than other 7400-series ICs. Is this because of a design flaw? I'm not sure (yet), but would like to find out. More recently, I saw a 680k 2W carbon resistor that read 1.3 meg out of circuit. As it turns out, it was in a high voltage portion of the circuit, and I suspect that electromigration caused its failure over time. Many of you are probably already aware that carbon resistors tend to increase in value as they age, though there are a few explanations too for that behavior, as I understand it. I would like to tie all of this together by researching older accelerated life testing schemes, examine how those parts actually fared, and see how current day models might be improved. If anyone has a collection of dead ICs (preferably those that have died inexplicably, and not by extreme overvoltage, for instance), I would like to talk to you about getting a few. If they are 7474s from Texas Instruments, ca. early 1970s, even better! Thanks in advance, Kyle

11 years, 4 months

7
8
0 0

Wang 2200 disk drives and printers on eBay

by johannesthelen＠hotmail.com

Any Wang fans here? I just found these at eBay: http://stores.ebay.com/Toll-Road-Truck-and-Trailer/Vintage-Computer-/_i.htm… I haven't seen too much Wang stuff on sale lately, I hope this tip would be useful for someone... - Johannes Thelen, Finland Old computer blog (Finnish) http://ennenmikrotietokoneita.blogspot.fi/Company site www.thelentech.fi

11 years, 4 months

1
0
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Working Commodore 65 on eBay

by oltmansg＠gmail.com

I presume I can't be the only one watching this eBay auction in disbelief. I'm wondering if this is a museum or not. Presumably a private collector would not have such deep pockets, but you never know! Over $13k USD and still a little less than 2 days to go! http://www.ebay.com/itm/Ultra-rare-Commodore-65-C65-DX64-prototype-working-…

11 years, 4 months

2
1
0 0

DG chassis and potentially PS.

by jws＠jwsss.com

I have a friend with a large stash of DG boards which comes from a collection of stuff he and his company had from supporting Novas. He has just the stash of boards and would like to get a rig to test them with. Ideally acquire, but from discussing what he wants to do he would probably need a minimal set including power, and the front panel to run tests. I wanted to locats contacts to put him in touch with that might be able to help him, and you and he can discuss the best way to do what he is after. I don't know if he wants to sell / trade all of them, end up with a working machine or what he may need to do, so he is flexible. I'll put you in touch with him in whatever manner you feel comfortable with. thanks Jim

11 years, 4 months

2
1
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olivetti programma 101 repair

by simski＠dds.nl

hello all, I'm in the process of repairing our 101 but i hit a solid wall finding out whats wrong with it. are there people with a working copy who could do some measurements on their copy? Unfortunately i have no schematic of the electronics, only the mechanics and PSU. I have made a crappy video of the scope trace of the delay line input and i'm very interested in a video of a working machine's delay line. :-) The video is here: http://youtu.be/llpwjGeldt0 and a partially repairlog is here: https://hack42.nl/wiki/Repair_Olivetti_Programma_101 als scematics are welcome as well. :-) -- Met vriendelijke Groet, Simon Claessen drukknop.nl

11 years, 4 months

4
7
0 0

Microdata disk/tape images

by ian＠platinum.net

Long shot, but does anyone know of any available disk/tape/paper tape/ROM images for any of the Microdata machines (800/1600) or the relatives (Intertechnique Multi-8/Multi-4, MAI Basic Four BB-II)? There?s a bit of documentation available - Bitsavers has a bit, and I have some MAI documentation that I?m in the process of scanning. I?m toying with the idea of emulating this machine, but I?m having difficulty locating any software for it. Thanks in advance. Ian

11 years, 4 months

7
15
0 0

11/23 clock issue

by jnc＠mercury.lcs.mit.edu

> From: Brent Hilpert > Well, try removing W1 to isolate the output of the xtal oscillator E15 > from inverter input pin E4.4. Thanks! Too late to try it today, but first thing tomorrow.. It seems like every time you answer one of my queries, I smack my forehead and say 'That's an excellent idea! Why didn't _I_ think of that!?!?' :-) > If you're not familiar with them, E15 is an integrated xtal oscillator, > not just a crystal - the crystal and oscillator logic are both in that > can I'm not familiar, so thanks for the tip. Wonder where I'll find one if that's what's bad... :-) > Could also (with W1 removed) pull E4.4 hi/lo while watching the > inverter output E4.16 to see if it responds correctly with the > inversion. Since it's a tri-state, I may need to hit the enable somehow. Oh, wait, I see, it's hard-wired on via a pull-down. (I wonder why they needed a pull-down? And I wonder what the test point is there for?) And I guess I need like a 5K series pull-up resistor to +5, right? (Ground I can just tie directly, right?) Anyway, thanks again for the help - very, very useful. Noel

11 years, 4 months

6
20
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11/45 hack?

by jnc＠mercury.lcs.mit.edu

> From: Eric Smith > The memory controller does have a Unibus port, but the Fastbus memory > modules are not on the Unibus any more than an RP04 disk drive is on > the Unibus. Ah, OK, I guess it all depends on exactly what one means by 'directly'... :-) I was using it in a high-level architectural sense: there's a 1:1 correspondence between UNIBUS addresses and Fastbus memory addresses; a UNIBUS read/write cycle completes immediately with the contents of that cell; etc - all quite different from the RP0x example. IOW, at a very high level, it looks like other 'memory on the UNIBUS'. > To a first approximation, the two Unibuses are *always* jumpered > together. I seem to recall reading (don't remember where, it was a long time ago) of some place that actually made use of the dual UNIBUS thing; they hung some other PDP-11 (don't recall what kind) off UNIBUS B, and ran a primitive multi-processor. It was some sort of high-speed data acquisition, or perhaps a real-time simulator - something like that. Anyone else know of any place that used the dual UNIBUS capability? Noel

11 years, 4 months

2
1
0 0

Crowdfunding for history book

by evan＠snarc.net

Hello cctalk'ers, Hopefully this message won't offend anyone --- I recognize that I might, and I apologize in advance if it does. As many of you know, I've been in the vintage computing hobby for about a decade. The first person I met was Sellam Ismail. He helped guide me as a newb collector of handheld/pocket computers. Somehow that led to me co-founding MARCH, publishing a 1,000-subscriber newsletter for a few years, rescuing a mainframe here and there, making the VCF East into a premier event, and becoming a "talking head" everywhere from BBC Radio to the Wall Street Journal. (My personal site is www.snarc.net if you really want to know more ... bring popcorn.) Now I'm asking for some personal help from the community. I'm trying something radical: crowd funding, so that I can finally finish the decade-long project of writing my book about the history of mobile computing. You can imagine how frustrated I feel when telling my family "I'm in the The Wall Street Journal!" but that I'm also dangerously under-employed (having been spit out of the technical journalism field after 16 years). It does not compute. Please visit this link for more information: http://fundrazr.com/campaigns/3wNcc. Thank you, - Evan

11 years, 4 months

8
12
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imitation game movie

by jnc＠mercury.lcs.mit.edu

> From: Chuck Guzis > Any more so, than, say, William Gardner Pfann? Another name I didn't recognize - I knew there was someone who did zone refining, and that it was critical, but didn't know the name. > From: Jon Elson > The XX system?? What's that? You likely already know of this, just not under this name; here: http://en.wikipedia.org/wiki/Double-Cross_System Briefly, during WWII, the British ran the entire German espionage system in the UK; initially, only for counter-intelligence purposes, but later on, to actively feed the Germans disinformation. > Another really great story is the X gerat, (X equipment in English) > that sent narrow, high frequency radio beams over England. For anyone who hasn't read it, I highly recommend R. V. Jones' book, "The Wizard War" - it covers all the various navigation systems (on both sides), and much more. I can also recommend "The Secret War", by Brian Johnson (the companion book to a BBC series), which covers that, radar, the V-weapons, code-breaking, and much more. > From: Johnny Billquist >> stored-program (in the sense of 'one memory holds both instructions >> and data') > What do you mean by "stored program" then? Err... :-) Noel

11 years, 4 months

2
1
0 0

Non-512-byte sector drive cloning?

by lbickley＠bickleywest.com

On Wed, 11 Feb 2015 18:04:58 -0500 (EST) Cory Smelosky <b4 at gewt.net> wrote: > On Wed, 11 Feb 2015, Roe Peterson wrote: > > > > > > > > > > >> On Feb 11, 2015, at 4:16 PM, Cory Smelosky <b4 at gewt.net> wrote: > >> > >>> On Wed, 11 Feb 2015, Al Kossow wrote: > >>> > >>>> On 2/11/15 1:56 PM, Cory Smelosky wrote: > >>>> netbooting NetBSD (install doable for that one.) > >>> > >>> You'll need to put something together that can talk to the raw > >>> scsi interface and issue your own read commands. Are they common > >>> command set drives? > >> > >> Should be. I don't believe CompuServe did anything too silly. > > > > What, actually, is the blocksize? 1024 or ? > > > > 576 or 2304. The "scu" utility, which is available for both NT and linux environments can change the blocksize - and scads of other parameters on most SCSI disks. It's powerful enough that you can brick a drive if you're not careful ;) I used to buy NOS Tandem SCSI HDD dirt cheap because they had a weird blocksize that would make Windows/Linux systems barf. I would then use "scu" to change the blocksize parameter of the drive to 512 - and do a low level format. Then I'd have a "standard" SCSI HDD for a fraction of the price of a "standard" drive. Of course you could change the blocksize of a drive to 576 - or anything you wanted - and then do a low level format for that blocksize. You can pickup scu for NT and linux (including help and summary pdfs) by anonymous ftp to my website via certain browsers or: ftp bickleywest.com user: anonymous password: your email address cd scu .... Regards, Lyle -- Bickley Consulting West Inc. http://bickleywest.com "Black holes are where God is dividing by zero"

11 years, 4 months

3
3
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SC40

by aek＠bitsavers.org

Is anyone on the list going to go after this? http://www.ebay.com/itm/221687223814

11 years, 4 months

13
20
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SIMH LGP-30 Progress.

by billdeg＠buzz1.com

On Wed, 11 Feb 2015, B Degnan wrote: > > via trial and error, and a lot of reading. I believe that loading the > > bootstrap manually is a must; one cannot use or create tapes otherwise. > > Only if your drum memory loses its contents. I don't know if SIMH has a > concept of non-volatile main storage (drum, core). And for the LGP-30, all > registers are non-volatile, too. When I fire up the SIMH and check 6300 we have 00000000 If the bootstrap came pre-loaded the first instruction of bootstrap should be in 6300 and read 10000000 so, no unless the bootstrap is somewhere other than where I think it should be, memory is completely blank when SIMH is loaded. > > In order to enter instructions into memory I first learned how to translate > > code from the various actual papertape sources, for example... > > > > "flexowriter entry"> 6300 P 0000' > > > > becomes > > > > sim> d -a 6300 10000000 > > Urks, that's sick... but SIMH should offer the possibility to enter the > mnemonics and addresses (or anything else since everything is mapped to > its four bit code) like > sim> d -a 3w00 p0000 (or d -a 6300 p0000 sim> d -a 3w00 p0000 Invalid argument The SIMH *should* accept mnemonics ... Believe me I tried EVERYTHING ... but unless there are hidden command switches you have to convert your code to machine format. Scoured the entire C source code looking for clues. :-) <snip> > sim> g 3w00 g is not a legal command. You have to tell SIMH to execute with a "SET CPU [command]" > > Anyways, SIMH is not very well suited for machines like an LGP-30 where > the user interaction with typewriter and console buttons for operation is > imperative. The SIMH version does officially work, but it is not really > user friendly in this case. Tell me about it. I have written to the SIMH user group, so far I have not received a reply with tips/testing done to verify "officially work" boundaries. > But the best would be if you use a drum image with 10.4 (the monitor) > already loaded, i.e. save the memory contents to a file and reload it on > the next incarnation of SIMH (there's a "START" drum containing 10.4 in my > simulator package, and an "ACT5" drum with preloaded ACT-V and > subroutines, these may be usable in SIMH, but I don't know). > > > repertoire. The hardest part is finding ways to enter Flexowriter key > > input via a modern keyboard, using SIMH commands. > > By using a simulator that offers the right frontend to the user (i.e. keys > and buttons as required by the machine operations) *g* > > Christian Christian....I am going to keep at it and then script a bootstrap that will load in SIMH, or convert tapes to SIMH format so they can be imported. I can see why you did what you did with your simulator. Makes a lot of sense to use function keys. Here is the bootstrap I am working to complete. I need to find equivalents to the Flexowriter commands, I have finished the memory insert commands, please send suggestions if you have them. sim> [first cpu fill c6300 in IR?] sim> d -a 6300 10000000 sim> d -a 6301 01000000 sim> d -a 6302 11016305 sim> d -a 6303 10000000 sim> d -a 6304 01000000 here is where I need to experiment, the code below is my first attempt: 6305 (skip) 6306 10106300 6307 10000000 6308 01000000 6309 (skip O.G.W.C flexo keys, still need to convert) 6310 00016346 6311 11116326 6312 10106322 6313 00000000 6314 10100000 6322 10116313 6323 11006309 6324 11016346 6325 10106307 6326 000wwwwj (entered into by flexowr., need to convert) 6346 0gwc0000 (entered into by flexor, need to convert) Bill

11 years, 4 months

1
0
0 0

imitation game movie

by jnc＠mercury.lcs.mit.edu

> From: Chuck Guzis > The point is that a lot of people were responsible for the development > of mechanical computation (I include electrical and electronic in this > definition). Just like the Internet... :-) > In fact, it could be argued that the ball-and-disc integrator was more > responsible for the eventual Allied victory in WWII than Turing's work > was. Sorry, are you referring to his work on computers, or his work in code-breaking too? If this latter, I would have to disagree. Respected military historians have suggested (of course, such alternative history is always speculative, one can't prove it) that the code-breaking work of the Allies shortened WWII by up to two years. I doubt mechanical fire-control computers (which is the primary military use of ball-and-disc integrators, as I understand it) had that significant an effect. > From: Johnny Billquist > And once more noone mentions Konrad Zuse, which in my mind beat them > all Well, two things. (And don't get me wrong, I admire Zuse and his work.) First, Zuse's work didn't really have much impact. You may disagree, but my sense is that if that bomb that destroyed the Z1 had gotten him too, the post-WWII world would still look pretty much like the real one. Second, his early machines (Z1-Z3) weren't stored-program (in the sense of 'one memory holds both instructions and data'). Yes, yes, I know the Z3 can (with a monstrous kludge) be Turing-complete, but it still wasn't stored-program - which to my mind, is _the_ key aspect of a real 'computer'. Interestingly enough, Babbage's machines weren't stored-program either; they had separate instruction and data tapes, like Zuse's (although they had conditional branching, which the Z1-Z3 didn't). Turing's invention of thex stored-program in 'On Computable Numbers' was really a fundamental leap. Noel

11 years, 4 months

2
1
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Anyone need spare 11/05 - 11/10 keys?

by jnc＠mercury.lcs.mit.edu

> From: Jason T > I have two 11/05s and one key .. The key is made by Chicago Lock Co. > and is stamped "GRB2." Perfect description of my 11/10 key. I'm now 99% sure they are all the same, but I think I'll have one made, and sent to the person nearest me, for an absolute confirmation, before I produce a cascade of them. (Plus to which the store probably needs to order more blanks - I'm not sure they have that many in stock! :-) > I'd like two please. Added you to my list. Noel

11 years, 4 months

1
0
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imitation game movie

by jnc＠mercury.lcs.mit.edu

> From: Chuck Guzis > So what's special about "electronic" computers? > Isn't this just a mere technological refinement? Logic gates can be > electrical, electronic, pneumatic, hydraulic and photonic There's a saying that a big enough quantitative difference becomes a qualitative difference. So electronic computing devices, because of their speed potential, are of a qualitatively different order than anything that involves moving matter around... :-) > In the game of firsts, where does Torres y Quevedo's "El Ajedrecista" > fit in? Alas, can't answer that - I've heard the name, but don't know much about his machine. > From: Jon Elson > Atanasoff and Beqrry did a GREAT job, but it wasn't actually > a "computer" by the Turing definition. Which is why I described it as the first digital electronic computing device... :-) Interestingly, one could add 'binary' to that description. The ENIAC of course wasn't, and I don't think COLOSSUS was either, in its counters, etc (but would have to check - does anyone know/recall). > all that was left were some drawings in a few binders. They published > NOTHING about the machine itself, and it was largely unknown for > DECADES! > ... > .. as far as I'm concerned, Atanasoff and Berry are a VERY interesting > footnote in early computing, but didn't actually contribute directly to > the development of computers. Well, there was a lengthy report written, but it was never circulated publicly because Atanasoff was trying to file a patent, and the patent attorney (IIRC) advised them not to publish until the patent application was filed - which it never was, with WWII starting. There was a contemporary press release about the device, which resulted in local coverage only. The whole thing did come within a hair's-breadth of winding up where Zuse's work did - a curiousity which did not have much impact on the world - but for one stroke of chance/luck: word of the machine somehow reached a man called John W. Mauchly, who came out to visit Atanasoff and Berry in June 1941, and spent almost a week there, talking with them, and studying the machine, and their written material. He later tried to claim that it was no big deal, and the ABC didn't really affect his thinking much - but that won't wash, you don't spend nearly a week intently studying something you think is irrelevant junk. (And Mauchly's letters to Atanasoff, written shortly after the visit, make clear that he was much taken with the ABC.) It's clear there is a very significant link between the ABC and the ENIAC - and the influence of the latter is clear. Noel

11 years, 4 months

1
0
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SIMH LGP-30 Progress.

by billdeg＠buzz1.com

Update on my attempts to bootstrap the SIMH Royal Precision Electronic Computer model LGP-30. I have been able to get through a lot more of the simulator-equivalent processing steps to match the input of the bootstrap programs via the native Flexowriter. I have been able to discover the syntax and basic I/O via trial and error, and a lot of reading. I believe that loading the bootstrap manually is a must; one cannot use or create tapes otherwise. Most SIMH's have some kind of software guide, the LGP-30 has none. I don't think this SIMH has the bootstrap pre-loaded. I am unaware of anyone who is using the SIMH simulator, although I have seen two non-SIMH LGP-30 simulators. One is in German. In order to enter instructions into memory I first learned how to translate code from the various actual papertape sources, for example... "flexowriter entry"> 6300 P 0000' becomes sim> d -a 6300 10000000 where 6300 = memory loc in drum memory, 1000 = P, 0000 = accumulator address (?). You can't store a "P" or "p" in memory. You have to convert to its Flexo binary equiv. Same goes for all instructions in the LGP-30 repertoire. The hardest part is finding ways to enter Flexowriter key input via a modern keyboard, using SIMH commands. It's all pretty slow going to patch together what I think would be a workable bootstrap install process, but I expect to have to try a number of variations before I get any response from the machine. I have a bootstrap but the hard part if the Flexowriter emulation. Who knows, maybe I will be able to contribute a software guide from all of this. I will document what I find and post on my web site, vintagecomputer.net. Bill

11 years, 4 months

2
1
0 0

Repairing A4000 leaky NiCd damage?

by ethan.dicks＠gmail.com

Happy New Year, all! Has anyone here gone through the process of reparing leaky NiCd damage to an A4000 motherboard? I _thought_ I had removed the battery some time ago but puttering around today, I cracked open the case to find the battery still there and some damage around U891 (a 74F245) and U850 (Bank 3 DIMM socket). I have washed off the residue but I may have to pull a DIMM socket to get access to the vias under it. I know the general process, but I'm curious if anyone has done this specifically to an A4000 board and has any tips. As I said, I'm probably going to have to pull the DIMM socket to get to all the damage. Barring success from running a dozen or so repair wires, would anyone happen to have a lead on an A4000 motherboard? Everything else in the machine should be good, the Daughter Card, the CPU card, etc... It's my only A4000, so I'd like to get it back up and running, or replace it if necessary. Thanks for any tips, -ethan

11 years, 4 months

9
14
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Anyone need spare 11/05 - 11/10 keys?

by jnc＠mercury.lcs.mit.edu

> From: Noel Chiappa > I'm about to go back for two more: does anyone else need one/any? If > so, please let me know One thing I need to check, before I get a whole stack made: does anyone know for sure if all 11/05's and 11/10's use the same key? (This is a standard, flat 'Yale'-type key, not the cylindrical key used in the 11/45's, etc.) The two I have do, but they came from the same place, and so might have been re-keyed to use the same key. Thanks! Noel

11 years, 4 months

3
2
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imitation game movie

by jnc＠mercury.lcs.mit.edu

> From: Jon Elson > How about John von Neumann? Geez, I think he really ranks above Turing, > at least as far as building real machines. This is unclear, for a whole host of reasons. First, you should look at Turing's ACE. Designed by Turing, at about the same time as the EDVAC, it spawned the Pilot ACE which was an important early British computer (commercialized as the Deuce). This machine is too large a topic to go into here, but may I suggest Copeland's admirable work on the subject, "Alan Turing's Automatic Computing Engine" - among other interesting aspects, he claims (and makes a good argument) that the ACE is RISC machine (the first). Turing was heavily involved in early computer work from the end of WWII until his death (e.g. at the start of that period, he attended the Symposium on Large Scale Digital Calculating Machinery at Hardvard in February, 1947). Second, when assessing the relative important of the contributions of Turing and von Neumann, there are a number of things to take into account. First, one needs to be aware that he and Turing were close colleagues; before WWII, Turing spent a year at Princeton working with von Neumann (who wanted to hire Turing as his assistant, at the end of Turing's year there). During WWII, Turing spent a long visit in the US (from November 1942 to March 1943), during which he spent a lot of time at Bell Labs, where when not doing war-work, he discussed computing machine with people there, including Shannon. So Turing's ideas on stored program computing devices were well known to von Neumann - who in fact seems to have always credited Turing with the idea (see Copeland, "Turing", pp. 130-131). Second, the 'EDVAC Report', despite the fact that it had only von Neumann's name on it, in fact reported on a series of design discussions between he, Eckert and Mauchly - and the latter two were rather annoyed that their contributions were not adequately recognized in it. (Again, see Copeland, "Turing", pp. 130-131 - although this point is treated at greater length in other sources I don't have the time to track down.) So von Neumann's _original_ contributions to computers may not be as big as some think. Noel

11 years, 4 months

2
1
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imitation game movie

by jnc＠mercury.lcs.mit.edu

> From: Jon Elson > such as to not evacuate Coventry when they knew it was next for getting > blitzed. Ah, this is alas an urban legend ('bogo-meme', to coin a nice neologism); started, IIRC, by Winterbotham. This has been demolished, by, among others, R. V. Jones, who was in a position to know (as the recipient of Ultra material at the Air Ministry), in his biographical work, "The Wizard War", pp. 147-151. He refers to evidence given by John Martin (Churchill's secretary, who was with him in the car that night), and John Colville (Assistant Private Secretary, who was on duty at 10 Downing St. that night). They are both quite clear that the target was unknown before the raid started; Jones gives the details on why not. > there are some descriptions that the actual wiring of the rotors was > done AT Bletchley I'd love to read about that - do you know/recall where you saw it? > If a German spy was to get his hands on the drawings for even one > (wired) rotor, they would have realized how thoroughly the British had > penetrated the Enigma system I am less certain of this. I seem to recall (alas, too busy to look it up, unless someone's really interested) that the Germans had something of a modern concept of code security, where it's assumed that the actual ciphering machine is compromised, and security depends on the security of the keys. Given the wide deployment of Enigma at the tactical level, the odds were good that the machine itself had been compromised. So for them to have found out that the British had the rotor wiring would not have been a big surprise, I would expect. However, had they gotten any kind of detailed description of the Bombe, it would have not been that hard to work out that its use was to break into Enigma. In that sense, the Bombe's overall design was in fact a bigger secret than the fact that they had the rotor wiring. And of course as a result of the XX system, the British were fairly sure that there were no German spies in the UK at the time, anyway. Noel

11 years, 4 months

2
1
0 0

RadioShack Store Closure List

by cctalk＠fahimi.net

Thought people would be interested to know: http://www.businessinsider.com/radioshack-store-closure-list-2015-2 -Ali

11 years, 4 months

11
15
0 0

OT: Can anyone identify this tool?

by sales＠elecplus.com

https://plus.google.com/photos/106111250846948401252/albums/6114301294379699 009?banner=pwa I picked it up, new, at the recycler, thinking it was a drill bit, but it is not. It is 13 cm long, and has a light or lens of some sort at the small end. The large end is about 3/4". It appears to be made of stainless steel. Engraved on it is QD90-6722. I added another pic, showing the larger end. There is a lens of some sort inside, and light shines through to the lens at the smaller end. Cindy Croxton

11 years, 4 months

2
1
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imitation game movie

by jnc＠mercury.lcs.mit.edu

> From: Lawrence Wilkinson > If you're going to condense 5 years of military, academic and > engineering development into a movie then things are going to suffer. > I think they did a reasonably good job. If the former's what they'd done, I'd agree. (And I can think of historical movies that have done that, and still produced a movie that was both very watchable, and reasonably accurate; e.g. in "The Gathering Storm", they've made Ralph Wigram stand in for a bunch of people, including him, who fed data to Churchill. I can live with that; too many characters would just confuse the average viewer.) But the Imitation Game writer(s) did a lot more than that. E.g. the whole bogus 'Turing versus his Blimpian manager who wanted to shut his project down' meme. That's completely bogus, 173 degrees out of phase with the truth, and clearly added purely to give, well, I'm not sure what. The thing is that what he and the others at BP (although he was primus inter pares, there were others such as Welchman, Tutte, etc who made massive, remarkable additions - and, as you point out, in the end it was an industrial-scale enterprise) did was so amazing, and they had to struggle against such difficulties, they didn't _need_ to 'sex up' the plot with that kind of stupid cliche. As far as I'm concerned, all those lame hackneyed plot elements just prove that the script-writer(s) were distinctly third-rate - because if they were actually any good, there's more than enough powerful material in Turing's actual story to make a much, much better movie, without relying on that kind of pathetic bilge. Noel

11 years, 4 months

1
0
0 0

imitation game movie

by jnc＠mercury.lcs.mit.edu

> From: Chuck Guzis > "the first electronic digital computer" I think that's a bit of a stretch; the ABC wasn't really a computer (as we think of them). As someone (forget the name) said, for those early machines, if you add enough adjectives, each one is the first <something>. Here's my list (in temporal order): ABC - first electronic digital computing device COLOSSUS - first large-scale electronic digital computing device heavily used for actual work ENIAC - first general-purpose electronic digital computing device Manchester Baby - first operational stored-program computer EDSAC - first stored-program computer heavily used for actual work Noel

11 years, 4 months

3
2
0 0

begging drivers/docs for obscure old PC/Mac hardware

by bear＠typewritten.org

Folks; Over time, I have accreted some assorted unusual hardware for PC and Macintosh, for which I lack the software to drive it. I know we have some terrific packrats on the list, so I'm shaking the tree, to see what might fall out. * DuPont Imaging Systems MacBlitz NuBus RISC processor. Apparently this is a Clipper CPU which runs UNIX independently of the host Macintosh, with IPC of some description. Has its own ethernet and SCSI interfaces. The Googles know almost nothing about this. * Vermont Microsystems Image Manager 1024 (IM-1024) 1024x800 PGC-compatible display adapter. Supposedly there were AutoCAD, GEM, Windows 1.x and 2.x drivers at one time. I'd love to see any of them. * Matrox "Space Machine" SM-1280 solid modeling graphics adapter. I'm not sure what kind of drivers were available; possibly it was just a set of development libraries for programming the board yourself. * Matrox PG-1280 (and/or the Microchannel equivalent MC-1281) graphics accelerator. I'd love to see any DOS-era PC drivers, or the PRPQ that let this board work under AIX on an RT. Somebody on the VC Forum thought he had these installed on a running system, but I never heard any further news. * Hercules Chrome TIGA (40 MHz TMS-34020) graphics accelerator. I have a Windows 3.1 driver for this, but I'm not sure the card is set up correctly. Mainly looking for documentation here. * IBM 5364 S/36 PC SSP, MCODE, and/or DOS host software. Somebody on the list kindly sent me a disk image of just enough of the DOS host software to prove my 5364 runs, but it's not a complete install and is missing some features I wanted to enable (keyboard maps mainly, IIRC). In addition, without the MCODE floppies the system can't be reconfigured for the various communications options (bisync, SDLC, etc.) my host PC has installed. Shoot, I thought there was something else, too. I guess I'll think of it eventually. Anyone? ok bear. -- until further notice

11 years, 4 months

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Windows CE

by sales＠elecplus.com

Someone asked awhile back for Windows CE software, but I did not save the post. I have a sealed package with CE 2.1, includes COA. Cindy Croxton

11 years, 4 months

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imitation game movie

by jnc＠mercury.lcs.mit.edu

> From: Fred Cisin > Or Zuse? Oh, $DEITY; forgot about him! So modify a few of the latter entries in my list to add 'electronic'... :-) Noel

11 years, 4 months

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Magnetic tape filesystem

by tom_a_sparks＠yahoo.com.au

I am wondering if there were any magnetic tape filesystem? I know that some micro you could give a name to your data/program on the audio cassette and they had a catalogue feature I also know about Linear Tape File System (LTFS) Has anyone tried putting cp/m or fat filesystem on audio cassette?

11 years, 4 months

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imitation game movie

by jnc＠mercury.lcs.mit.edu

> From: Jon Elson > has anybody seen the Imitation Game movie, ostensibly about Alan Turing? > .. > Any comments? I have, and I also have extensively studied both WWII codebreaking, and Turing's life and work. It's an OK movie, but as any kind of historical thing - fuhgeddaboutit. There are so many 'errors' (changes) that it's basically impossible to list them all. They ran about about one error/change per minute, throughout the whole movie. It's more wrong than right, actually. About the only thing that was absolutley accurate (other than the basic concept, that Turing worked at BP and helped break German codes) was Joan Clarke's soliloquy in his flat at the end of the movie, describing his contribution to the world. > Various descriptions have hundreds of people at Bletchley wiring the > rotors and doing much of the other work. The Bombe parts must have been > made in machine shops across England. Hmm. The descriptions I've seen of their manufacture (e.g. Gordon Welchman, "The Hut Six Story", pp. 138-141, Hugh Sebag-Montefiore, "Enigma: The Battle for the Code", pp. 56-58) all indicate that the machines were manufactured by British Tabulating Machines in their Letchworth factory (about half-way between BP and Cambridge), and only came to BP once they were completed. There was a lot of local sub-contracting of small sub-assemblies which didn't require machining, though (see Welchman). Noel

11 years, 4 months

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Radio Shack

by r_a_feldman＠hotmail.com

Most people posting in this thread have assumed that all Radio Shack stores were closing. That is not the case (at least for some time). Only about half of the company-owned stores are being closed. RS has published a list of the 1784 stores it wants to close: http://radioshackcorporation.com/pdfs/RS-Store-Closure-List_020415.pdf. Another 1750 stores will be taken over by Sprint for cell phone "store-within-stores" and about 1000 stores owned by franchisees are not part of the Chapter 11 bankruptcy proceedings. According to the Register (http://www.theregister.co.uk/2015/02/10/radioshack_store_axed/), the closings will take place by March 31. Two stores in downtown Chicago, near where I work, are on the list, so I will be watching them to see when they start selling off the merchandise. Bob

11 years, 4 months

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8" drive advice...

by supervinx＠libero.it

I need to connect an external 8" floppy drive to the FDADAP card. I've found two drives: NEC FD1165A and Shugart SA851. I have to buy ine of them. I'm about to choose the NEC one, since it doesn't need an AC power source. The Shugart SA851 is targeted 115 VAC, and I live in Europe. Beside power supply questions, are there other reasons why I should choose the Shugart? Hard sectored disk support? I only have to read/write IBM S/36 and 5120 floppy disks... Thanks! -- Vincenzo (aka Supervinx) --==ooOoo==-- My computer collection: http://www.supervinx.com/Retrocomputer --==ooOoo==-- You can reach me at: www.supervinx.com www.facebook.com/supervinx http://www.youtube.com/user/supervinx http://www.myspace.com/supervinx

11 years, 4 months

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11/45 hack?

by jnc＠mercury.lcs.mit.edu

> From: Paul Anderson > it's not part of the 128 kw or 256 kb limit of the 45 Err, don't think so - that limit is in the addressing hardware in the CPU as well as in the UNIBUS. > From: Eric Smith > The 11/45 (or 11/50, 11/55) Fastbus memory, whether MOS or bipolar, is > not directly on either Unibus Actually, my understanding is that it is on UNIBUS B (or 2), via a second port to the memory; see this post: http://www.classiccmp.org/pipermail/cctalk/2015-February/003460.html which gave my understanding of how it works. And of course if you connect the two UNIBI together, it's therefore directly on UNIBUS A (or 1), as well. I.e. DMA devices can do transfers to/from it. Noel

11 years, 4 months

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Memorex MRX IV 6250 BPI SuperReel Tape on sale - 4 reels maybe new

by mazzinia＠tin.it

It's not my auction, have no relations.. 4 Reels 2 packages Memorex MRX IV 6250 BPI SuperReel Tape VAX DEC IBM Vintage http://cgi.ebay.it/ws/eBayISAPI.dll?ViewItem&item=371253355734&category=175…

11 years, 4 months

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OT : SAB3012 datasheet wanted

by ard＠p850ug1.demon.co.uk

This is sort-of off-topic : Does anyone have old-ish (1980s) Philips/Mullard/Signetics data books around. I am looking for a data sheet (or at least a pinout) for the SAB3012 remote control receiver IC (no, I do not mean SAB3021). I can find nothing on the web. (It's only sort-of off-topic as the IC is used in an old Viewdata / Prestel set which I guess is classic computing) -tony

11 years, 4 months

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Classic computing goes mainstream....

by jdr_use＠bluewin.ch

Even the BBC is reporting : http://www.bbc.com/news/business-31188257 Wil we see a flood of speccies and BBC-B ? Jos

11 years, 4 months

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Answers: Weekly Classic Computer Trivia Question (20150204)

by dpi＠dustyoldcomputers.com

On Wed, Feb 4, 2015 at 9:37 AM, Doug Ingraham <dpi at dustyoldcomputers.com> wrote: > This time lets refer to some classic fictional computers used in movies. > Everyone probably knows about the HAL 9000 used in the movie 2001 a Space > Odyssey. > > What was the name of HAL's sister computer in the movie 2010 Odyssey two? > SAL 9000 > That was a warm up question. This one should be more difficult. > > What was the designation of the computer in the movie WarGames and what > does it mean? > WOPR which stands for War Operation Plan Response. And finally, > > As silly as it was the movie Hackers referred to the mainframe computer in > the movie as a Gibson. > > Where did the term Gibson come from? > It is believed to be a reference to the author William Gibson who coined the term Cyberpunk in his short story Burning Chrome (1982 Omni) and then his novel Neuromancer (1984). Hope you all enjoyed this one! -- Doug Ingraham PDP-8 SN 1175

11 years, 4 months

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Anyone need spare 11/05 - 11/10 keys?

by jnc＠mercury.lcs.mit.edu

I've discovered a local place that can create them, and just had one made, and it worked fine. I'm about to go back for two more: does anyone else need one/any? If so, please let me know (reply to me _only_, please - no need to gunk up the list with that). They'll be $2 each, to cover costs only. Noel

11 years, 4 months

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xylogics 650 manual

by jacob.ritorto＠gmail.com

Hola, According to this thread from BITD ( http://ana-3.lcs.mit.edu/~jnc/cctalk/1999-July/1414.html ), I have what appears to be a Xylogics 650 sitting here in anti-static wrap, glistening like brand new. Anyone have a manual? Tried replying to Dan, but no dice.. thx jake

11 years, 4 months

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RA-81 issues

by g-wright＠att.net

Did not see this come through so here it s again. I have a rack full of RA81's, all Pass Rom base self test. If I try to spin up one of the drives, It will start to spin up and then just stop. There are no front panel lights that come on or codes on the terminal screen. all 3 drives do the same. These are not connected to a controller, and the manual does not say this is need. The forth one has no drive and the motor seems to turn hard, is there a brake on the motor ??? - what I'm I missing here Thanks Jerry

11 years, 4 months

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11/45 hack?

by jacob.ritorto＠gmail.com

Hi, Man. I'm becoming concerned that I can't fit any of the significant features that I want in my 11/45 without making uncomfortable sacrifices. The first 25 slots are for an initial "unibus a" terminator, cpu, floating point and memory, which, since I only have one bipolar matrix, is an enormous waste of like ten slots (they're wired for weird voltage and would presumably explode other boards installed there, right?). So then there are three slots available at the end, 26, 27, 28 that are also marked "non-standard voltage." I guess that means that putting normal boards in there is right out, too. Anyway, the unibus out and bridge 9200 jumper that connects unibus a and unibus b are supposed to go there. That's it for the main backplane. The next three small backplanes are core. They take up the rest of the chassis. I don't want to give up my core because core is cool, right? So this means I've nowhere to put the hex boards I need to run. I need to install more memory (planning to use MS11 (124KW M7891)), ethernet, some sort of hex height SMD disk controller (SC21,etc.), possibly an RL11, and a DZ11. That's at least four, maybe six hex-height boards I need to accommodate. I'm going to duck after asking this, but would it be at all feasible to rewire the main 11/45 backplane to get rid of the weird voltages in those bipolar slots so they'd accommodate normal boards like these? Short of that, what can I do? I definitely don't want another chassis. I guess I have to sacrifice my core to make way for a second "normal" dd11-type backplane to house the modules I need to run. So sad. <duck> jake

11 years, 4 months

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11/23 clock issue

by jnc＠mercury.lcs.mit.edu

> From: Tothwolf > Before I forget again, did you check for +5V on pin 1 (enable) when you > were testing your existing oscillator? Wow. Never thought to try that. Then again, I don't look for +5V on your average 74xxx when I'm debugging, either! :-) I mean, it's a trace, the solder on the pin looks good, that's as far as I go, usually! And there's nothing shown as connected to that pin on the circuit diagram. So I looked, and... it's at ground (or floating). The only pin that has anything is 14, at +5V (expected). But I looked online for some datasheets for similar oscillators, and some of them say 'pin 1 - N/C'. Are yours tri-state? (That's the enable pin on the tri-state ones.) I suppose even if yours are tri-state, I can still use them; a quick ohmmeter check shows that pin 1 isn't connected to either power or ground, so I can probably tie it high (via a resistor, which in addition to being normal practise, will prevent a major disaster in case I'm confused - a state I'm often in :-). Noel

11 years, 4 months

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Radio Shack

by evan＠snarc.net

So ..... Radio Shack is (more or less) finally dead. There are still plenty of RS stores open for business. (Although I read this morning that they're not getting new shipments, which makes them essentially clearance stores.) Apparently the company is legally allowed to close a maximum of 200 stores per year. Or something like that. Horn-tooting: the Wall Street Journal interviewed me about RS back at World Maker Faire last fall. They published the story online today and it'll be in print tomorrow. http://www.wsj.com/articles/strategic-confusion-put-radioshack-at-the-mercy… Scroll aaaaaaaaaaaall the way down to the bottom. (LOL, yeah, I'm important!)

11 years, 4 months

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Differences between PDP-11/83-84 M8190-AB/AC and AD/AE CPU cards

by jnc＠mercury.lcs.mit.edu

> From: Jerome H. Fine > for the PDP-11/83 (usually in a BA23 or a BA123), the backplane is > wired so that the PMI memory is activated correctly WHEN the first > memory board is in slot 1 and the CPU follows the memory boards. That's an artifact of the way Qxx/CD backplanes, and PMI CPU cards, are wired. (And you probably already knew this, but just to be explicit... :-) For the backplanes, with few exceptions, pin nQm2 (where n is the slot #, Q is C or D, m is A-V, in the DEC alphabet) is wired only to pin (n+1)Qm1 - i.e. pin Qm1 is not wired through to all slots. In other words, the CD bus is not carried _through_ a slot, only _between_ slots. The PMI bus on the CPU is only wired to the top (i.e. 1) pins. So if you plug a PMI CPU into a normal Q22/CD backplane, the only slot that receives the PMI signals is the slot _before_ the CPU. Hence the requirement to plug memory cards in _before_ the CPU when using a Q22/CD backplane for PMI. The 11/84 backplane is different; per the backplane prints in EK-PDP84-TM-PR2, the 1-side pins on the Q22/'CD' portion of the backplane _are_ all bussed together. (Note: from what I can see in the backplane prints in EK-PDP84-TM-PR2, none of the other CD bus pins are bussed together; in particular, the staggered connections from nCA1 to n+1CC1, nDA1 to n+1DC1, etc found in the real Qnn/CD backplane don't seem to be there in the 11/84 backplane. So it's not _real_ Q22/CD - it's probably better to call that section of the 11/84 backplane Q22/PMI. PMI _can_ run over a normal Q22/CD backplane, though.) >> Would a KDJ11-A board even work in an 11/84 backplane? > I meant the KDJ11-BD board or the M8190-AC. > ... > it seems reasonable to hope that the PDP-11/84 can also use the > KDJ11-BD instead of the KDJ11-BF Ah. My guess (having not looked at the 8190-AC in detail) is that to the extent the M8190-AC implements PMI, it should work fine in an 11/84. Noel

11 years, 4 months

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Differences between PDP-11/83-84 M8190-AB/AC and AD/AE CPU cards

by jnc＠mercury.lcs.mit.edu

> From: Noel Chiappa > (I suspect, but have yet to verify, that this is in part because bus > grant lines are run directly from that slot to the UNIBUS adapter slot.) So it turns out I was half-wrong, but half-right. I was paging through a copy of EK-PDP84-TM-PR4 (PDP-11/84 Technical Manual) which I recently acquired: in section 2.1.14 "Backplane (H9277-A)", pg. 2-6, the following sentence appears: Bus signals BDMGI (pin AR2) and BIAKI (pin AM2) for slots 2 & 3 are jumpered on the front of the backplane. (This is not in any other version of EK-PDP84-TM, of which I have several.) So I got out my spare 11/84 backplane, and sure enough there are two jumpers, W1 and W2. The traces connected to them are, luckily, on the surface, so it's possible to see where they go: one end runs to a trace connected from slot 1 to slot 2, and the other to a trace connected from slot 3 to slot 4. EK-PDP84-TM-PR2 actually contains (pp. D-4 to D-8) prints for the backplane. Unfortunately, they are very low-res, and only partially readable, but one can see, on the bottom of the first print (D-4), the two jumpers. The associated traces do indeed connect to AM2 (BIAKI), AN2 (BIAKO), AR2 (BDMGI) and AS2 (BDMGO). In other words, when the jumpers are in, the CPU's BIAKO/BDMGO pins are connected directly to the UNIBUS adapter's BIAKI/BDMGI pins; when they are out, those signals are routed through the two 'memory' slots, in the normal QBUS manner. What this strongly suggests to me is that those two slots _can_ function as real QBUS slots. Otherwise, why arrange so that the grant lines can run through them? I haven't examined all the other pins, to make sure they contain the full set of QBUS signals - in part because I don't want to pore over those poor images! (Speaking of which, does anyone have a copy of either 11/84 Field Maintainance Print Set - MP-01955 or MP-02536? Neither one seems to be online - at least, as best I can tell, from some Googling, although others may have better Google-fu than me - and it would be fabulous to have access to them.) But I do strongly suspect they can function that way; at some point, when I have an /84 running, I'll actually try them out. As to why DEC put this capability in, and then didn't document it or use it - who knows? Maybe they though it would introduce extra complixity in the user instructions, or something. Anyway, I think we are close to cracking this particular puzzle... Noel

11 years, 4 months

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Differences between PDP-11/83-84 M8190-AB/AC and AD/AE CPU cards

by jnc＠mercury.lcs.mit.edu

> From: Jerome H. Fine > With regard to the MSV11-JD in the PDP-11/84, was this board placed > after the KDJ11-AE board or before it? After. The CPU _has_ to go in slot 1 on the 11/84 backplane. (I suspect, but have yet to verify, that this is in part because bus grant lines are run directly from that slot to the UNIBUS adapter slot.) > Also, has anyone ever used a KDJ11-AC board with the 15 MHz crystal in > the PDP-11/84 backplane? I can't see why it should not work, but just > maybe the PDP-11/84 backplane and a simple KDJ11-AC board are not > compatible. Would a KDJ11-A board even work in an 11/84 backplane? It wouldn't (couldn't) do the special PMI (actually, we ought to distinguish between 'QBUS PMI', such as in the 11/83, and 'UNIBUS PMI', as in the 11/84; the second is a superset of the first, I believe) protocol, so it wouldn't work with the UNIBUS adapter. See also Micronote #39, "Differences between KDJ11-A and KDJ11-B". Noel

11 years, 4 months

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Sharp PC-1600 keyboard issues

by derschjo＠gmail.com

Another day, another project (the DAP will wait until I have the wiring to support it...). This week a bunch of "Refurbished" Sharp PC-1600s showed up on eBay for cheap and I snagged one; it arrived this evening. It looks like the unit is effectively new-old-stock; it doesn't seem to have been used since Sharp refurbished it back in the day -- it arrived with the original Sharp-branded batteries in the compartment. Amazingly, only one of the four batteries leaked, but only a tiny bit and there's no obvious corrosion anywhere from it (whew). The PC-1600 powers on and mostly behaves normally after an "All Reset" but the keyboard is having trouble; here are the symptoms: - Keys A-K on the 2nd row of the QWERTY section do not function ('L' does). - The "Shift" key doesn't work properly -- hitting it doesn't cause the "Shift" annunciator on the LCD to light up. However, it does seem to do *something* in that if you hit Shift+another (working) key, nothing happens at all (for example, Shift+5 should result in a left curly brace but does nothing at all.). - The "SML" key does not put the machine in lowercase mode, instead one of the Kanji (i believe) annunciators gets toggled. This has no other obvious effect (uppercase letters are still produced from the working letter keys...) - Hitting the "KB II/Click" key (farthest right under the LCD) turns "Key Click" mode on even though Shift is not being depressed. (Or maybe this is normal behavior -- I can't find this key described in the manual...) Otherwise, the thing seems to be working OK, it'll calculate fine and I can enter/run small programs (that don't use the home row for entry...) I've found the Technical Drawing set here: http://www.sharp-pc-1600.de/Schaltpl%8ane%20A3/Technical_Drawing_DINA3.pdf which makes it obvious that the dead home-row keys are related to the KIN3 line from the keyboard matrix; I note that the keyboard signals are brought to the edge of the PCB and connected to a membrane layer which contains additional circuitry, including what looks to be an IC that does the keyboard decoding. My first guess would be dirty contact between the PCB and this membrane (esp. since the lines in question are close to a hole in the battery compartment where the aforementioned 30-year-old batteries were...) but I'm a bit nervous to disassemble and clean this without knowing how it's held together. Anyone have any experience here? Any tips? Thanks as always, Josh

11 years, 4 months

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Differences between PDP-11/83-84 M8190-AB/AC and AD/AE CPU cards

by jnc＠mercury.lcs.mit.edu

> From: Henk Gooijen > Maybe a few PALs have to be a faster version, but I do not expect that. > The 15 MHz to 18 MHz is not that big of a difference. I did wonder about that, but they boards use parts from a number of different chip companies (both the PALs, and the PROMs), so since I don't know how to read those parts for speed variants, I couldn't say. > From: Johnny Billquist > The 11/84 variant is pretty much a PMI bus all the way, but I seem to > remember a couple of signals defined differently even in the 11/84 > compared to the 11/83. If you run across where you saw that, I'd be curious. The 84's use is, as you point out, different, since it includes the CPU<->UNIBUS adapter protocol for UNIBUS cycles. But I would have assumed that it was a plain superset of the 83's (not that I have read much about 11/83's... :-). > From: Jerome H. Fine > The MSV11-JB (1 MB) and MSV11-JC (2 MB) are used in the PDP-11/84. The > MSV11-JD (1 MB) and the MSV11-JE (2 MB) are used in the PDP-11/83. Err, not sure this is correct: I got an 11/84 with an MSV11-JD in it. As someone pointed out in a later message, the difference between the B/C and D/E is that the B/C only work as PMI memories, their QBUS functionality has some issues (IIRC, something to do with QBUS block transfers not working correctly). > In addition, for at least the PDP-11/83, the PMI memory must be placed > into the backplane ahead of the CPU for the memory to function as PMI > memory. That may be the only position allowed for the memory for the > PDP-11/84. The 11/84 backplane has two special Q22/CD slots after the processor slot which the memory goes in, with the CD sections wired to through-connect the PMI pins. I have this sneaking suspicion that the Q22 portions of those two slots aren't _real_ QBUS slots (so you can't plug a QBUS device into them if you aren't using them for memory :-), because I suspect they didn't run BIAK and BDMG to those slots, but rather piped them directly to the UNIBUS adapter slot. My reasoning for that is that if you don't plug in a memory card in one of those slots, you don't have to plug in a grant continuity card, so.... Anyway, I have a spare 11/84 backplane, and one day I'll get around to poking at it with an ohmmeter to verify that suspicion. > I seem to remember that when two memory boards are used, they should be > the same. Really? That would surprise me. Noel

11 years, 4 months

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Differences between PDP-11/83-84 M8190-AB/AC and AD/AE CPU cards

by jhfinedp3k＠compsys.to

Does anyone know why DEC would have MSV11-JC boards for use ONLY with a PDP-11/84 and the MSV11-JE boards which could be used with BOTH the PDP-11/83 and the PDP-11/84? It seems inconsistent. >Glen Slick wrote: >>On Wed, Feb 4, 2015 at 7:09 PM, Jerome H. Fine <jhfinedp3k at compsys.to> wrote: > > >>Longer explanation: The PMI memory used in the PDP-11/84 is sufficiently >>different >>from the PMI memory used in the PDP-11/83 that the magic smoke might be >>released >>if the incorrect PMI memory is used. The MSV11-JB (1 MB) and MSV11-JC (2 >>MB) >>are used in the PDP-11/84. The MSV11-JD (1 MB) and the MSV11-JE (2 MB) are >>used in the PDP-11/83. >> >The MSV11-JD and MSV11-JE are documented as being compatible with both >the PDP-11/84 and Q-bus systems. The documented restriction is that >the MSV11-JB and MSV11-JC are only compatible with PDP-11/84 systems >and incompatible with Q-bus systems. > >http://www.bitsavers.org/pdf/dec/qbus/oemMicronotes.pdf > >uNote # 028 >MSV11-Q/M/J MEMORY COMPARISONS > >MSV11-J >------- >The MSV11-J has four versions, the MSV11-JB and the MSV11-JC which are >used in the PDP-11/84 UNIBUS systems and the MSV11-JD and the MSV11-JE >are used in either the MicroPDP-11/83 Q-bus systems, or the PDP-11/84 >UNIBUS systems. All four modules use ECC memory for error correction, >as well as using 256K bit MOS RAM parts on either a half for fully >populated quad size module. > >NOTE: >----- >NONE OF THE FOUR MSV11-J MODULES CAN BE PLACED IN A Q/Q BACKPLANE >SLOT. IF THIS IS ATTEMPTED PERMANENT DAMAGE WILL BE DONE TO THE BOARDS >AND TO THE SYSTEM. > >The MSV11-JB (M8637-BA) is a half populated quad size PMI memory >module containing 1MB of memory. The second version of the MSV11-J is >the MSV11-JC (M8637-CA), this is a fully populated MSV11-JB quad size >PMI memory module containing 2MB of memory. These two module can not >be used in a Q-bus system due to gate array incompatibilities, and can >only be used in the PDP-11/84 systems which use the UNIBUS/PMI bus >interface (KTJ11-A). The third version of the MSV11-J is the MSV11-JD >(M8637-DA) which is a half populated quad size PMI memory module >containing 1MB of memory. The last version of the MSV11-J is the >MSV11-JE, (M8637-EA) which is a fully populated MSV11-JD quad size PMI >memory module containing 2MB of memory. These last two modules can be >used with either the MicroPDP-11/83 system which uses the Q-bus/PMI >bus interface or the PDP-11/84 system which was mentioned above. > >Although the MSV11-JD and MSV11-JE are PMI memories they can be used >in two other Q-bus configurations. >(more details follow...) > THANK YOU for the correction. After 20 years, the memory becomes a bit hazy. Also, I have only the 2 boards which are both 2 MB, so there must have been some confusion when I was told that a 1 MB and a 2 MB board should not be combined. It is good to know that is also not true. Does anyone know why DEC would have both MSV11-JC boards for use only with a PDP-11/84 and MSV11-JE boards which could be used with both the PDP-11/83 and the PDP-11/84? I have never worked much with Unibus systems and never with a PDP-11/84. Also, thank you for confirming that these memory boards MUST NOT be used in a Q/Q backplane. At one point, the MSV11-JE memory boards were equally priced with other 2 MB Qbus memory boards since most individuals thought they could be used only as PMI memory. I have no idea what the current prices are. Jerome Fine

11 years, 4 months

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When to re-condition electrolytics

by jnc＠mercury.lcs.mit.edu

So, I'm about to bring up an old 11/10, and step a) is going to be getting the power supply up. So this means probably reconditioning some old electrolytics. So my question is 'should I _always_ recondition old caps, or is there some way to tell if they are still OK'? E.g. if they check out OK on an ohmmeter (no dead shorts), and also on a ESR meter, does that mean they are good to go? Or should I just always recondition them? I ask because this power supply (H750) seems to be a switching supply, and so I can't use the simple VARIAC hack, I'm going to have to do each capacitor individually. (For you experienced hardware guys, this is probably No Big Deal, but I'm mildly terrified... :-) Noel

11 years, 4 months

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