test-drb June 2009

test-drb@ccmp.vtda.org

233 participants
404 discussions

by derschjo＠mail.msu.edu

Hey All -- So, instead of debugging my 11/40 last night I decided to get my 11/73 running again since all it needed was to be put back together :). Installed 2.11BSD on it from TK50 tape, and it was only slightly faster than the last time I installed it -- at 19.2kbps using vtserver :). At any rate, it's online, so to speak, so if you feel like playing around, just telnet to yahozna.dyndns.org. (login: guest, password Guest1!) Be kind, it's not the speediest thing out there. I figure it's rather unlikely it'll be hacked into, and if it is, worst case I can restore the drive from the image I made of it... Is there a repository of source/binaries for stuff people have (back) ported to 2.11BSD? I'm thinking of seeing if I can squeeze an older version of Apache on it if I ever find the time... - Josh (Specs, just in case anyone cares: 11/73 CPU, 2mb RAM, TK50 tape, DEQNA ethernet, TS11 -> M4 9 track (currently non functional) Emulex U07 SCSI -> SCSI->IDE bridge -> IBM Microdrive (4gb))

15 years, 1 month

Remembering the true* first portable computer • The Register

by woyciesjes＠sbcglobal.net

And on the last page, they give credit to CHM for letting them "drool over the machinery": http://www.theregister.co.uk/2009/06/05/tob_minuteman_1/ -- --- Dave Woyciesjes --- ICQ# 905818 --- AIM - woyciesjes --- CompTIA A+ Certified IT Tech - http://certification.comptia.org/ --- HDI Certified Support Center Analyst - http://www.ThinkHDI.com/ "From there to here, From here to there, Funny things are everywhere." --- Dr. Seuss

15 years, 1 month

Transistor Substitution

by ajp166＠bellatlantic.net

> >Subject: Re: Transistor Substitution > From: ard at p850ug1.demon.co.uk (Tony Duell) > Date: Wed, 10 Jun 2009 20:11:44 +0100 (BST) > To: cctalk at classiccmp.org > >> >> I have a couple of DEC machines which I need to replace a few components >> >> on, and also stock up spares of others. With the transistors and diodes, >> >> however, I often can't find a direct replacement - and don't know how to >> >> figure out what a modern substitute is. >> >> >> >> For a 2N3009, for example, I can find basic information and a datasheet >> >> online easily enough - but as for choosing a functional, available >> >> substitute for it, I'm honestly not even sure where to begin. > >[...] > >> Way too much information.. What he needs to know is what can he buy now that >> should work to replace a 2n3009? > >There is a saying in England : > >'Give a man a fish, you feed him for a day. Teach a man to fish, you feed >him for life'. Yes Teach a man to fish... Often the problem has greater scope. Recently I when through a similar situation.. problem was the psrson could solder and somewhat read a schematic.. Terms like breakdown voltage, Ic, Beta and Ft were completely lost as he had no context other than what building a lot of kits taught him. So sometimes the scope is not only teaching fishing, but what a fish is and why one wants to catch one. >I try to use that principle when posting here. I try to show how solve >similar problems in the future. None of us will be around for ever [1] >and I think it's important the information, methods, 'tricks', etc get >passed on I was trying to be light but maybe a ;-) may have helped. >[1] It would only take one careless mistake when repairing an SMPSU... > >As the bit of the original message I've left above semems to suggest, the >2N3309 is an example, and the OP possibly needs to substitute other >transistors as well. There are many substitutes possible, likely dozens or more. I picked one that is generally easy to find in many places. The other case was without context I ahd to pick a robust solution rather than one that oen that might work. An example is for simple logic a 2n3904 or the plastic pn2222 should do fine but if it drives a relay or lamp the added current capability if the 2n2222 is a better choice or maybe 2n2219. >> The only case where they type transistor is a bit fussy is some of the faster >> flip chip cards (logic) and SMPS. > >Maybe in DEC equipment... But I can assure you that the HP9100 is >'touchy'. It's not particularly high-speed, it's certainly not an SMPSU, >but you will have 'fun' working out what transistors to use. There were some applications that DEC used transistors that wanted faster transistors, core drivers and head drivers being those that easily come to mind.. Others it was sufficient to insure it was SI or Ge and the proper PNP or NPN. If the design had any vestage of ECL or other non-saturating logic then a lot of parameters become important. Then it is more difficult. SMPSUs are an animal and yes the wrong part there can cause pain or at best end up in a troubleshooting endless loop. Some old logic from the days before silicon devices can be fussy as they use MADT and other generational germainium devices and yes those do not substitute well without a carefull examination as to how they are applied. The gates and flipflops from the TX2 are a good example of early fast logic using germainium transistors. For context fast in early transistor computer designs is anything over a few megahertz (like greater than 1mhz!). Allison >-tony

15 years, 1 month

Looking for IMI 5018 MFM drive

by snhirsch＠gmail.com

Title says it. Need to replace the drive mechanism in one of my Corvus flat-cable drives. Firmware expects 6-heads and 306 cylinders and gets boggled by anything larger, unfortunately. Could also probably work with Seagate ST419 or Rodime RO203, which are the only other drives I've found with the same geometry. Steve --

15 years, 1 month

Oddest mismatch in hardware for a given purpose...

by tshoppa＠wmata.com

Josh writes: ? the processor in the MK-85 ? is a Russian PDP-11 knockoff. It's not a power-efficient CPU by any ? means, The joke in the cold war era was this: A Russian scientist shows up at a international conference with his amazing whiz-bang wrist computer. It has word processing, E-mail, advanced calculations, etc., all built-in. Every attendee comes by and Expresses complete amazement. At the end of the day when it's time to pack up, the Russian scientist asks "could someone help Me with my suitcase?" One, two, three others come to help him but are barely able to move The suitcase. They ask "what do you have in here that could be so heavy?" The answer: "It's the power supply for my wrist computer". Tim.

15 years, 1 month

Help with MS11-M and /24 or /44

by dundas＠caltech.edu

Does anyone have a pair of (working) MS11-M memory modules (any size, both the same) in a PDP-11/24 or /44? [I believe those were the only models to support that memory.] If so, could I talk to you offline about how they interleave? Background: I'm working on a memory simulator for SIMH (PDP-11). I have it working with most parity memory models and the ECC models as well. [The MS11-M uses 7-bit ECC.] I have the MS11-M successfully simulated in a non-interleaved manner now. I'm struggling with getting interleaving to work correctly with the diagnostics. What I'd like to do is give someone a short fragment of code to execute on their machine and let me know the results. This would help me finish the simulation. Yes, I have carefully examined the documents Manx turns up, but that information is not sufficient for my needs. Alternatively, if someone had the listings for either XXDP diagnostics ZMSDD0 or ZMSPC0, that would also likely solve the problems I'm encountering. As a teaser, here's SIMH simulating a /44 with 2 MS11-M (128kW) modules, non-interleaved: .R ZMSDD0 ZMSDD0.BIN CZMSDD - MS11L/M MEMORY DIAGNOSTIC 11/44 CACHE AVAILABLE FS COMMAND MODE COMMAND:99 COMMANDS AVAILABLE: 0 = EXIT 1 = READ CSR 2 = LOAD CSR 3 = EXAMINE MEMORY 4 = MODIFY MEMORY 5 = SELECT BANK & PATTERN 6 = TYPE CONFIG MAP 7 = SOB-A-LONG TEST 8 = ERROR SUMMARY 9= REFRESH TEST 10= SET FILL COUNT 11= ENTER KAMIKAZE MODE 12= EXIT KAMIKAZE MODE 13= TURN CACHE OFF 14= TURN CACHE ON 15= TEST SELECTED BANKS 16= TEST ALL BANKS 17= ENABLE TRACE 18= DISABLE TRACE COMMAND:11 ENTERING KAMIKAZE MODE COMMAND: LEAVING FS MODE 256K OF MS11-M 256K WORDS OF MEMORY TOTAL MEMORY CONFIGURATION MAP 16K WORD BANKS 1 2 3 4 5 6 7 012345670123456701234567012345670123456701234567012345670123 ERRORS CPU MAP 1111111111111111 INTRLV ---------------- MEMTYPE MMMMMMMMMMMMMMMM CSR 0000000011111111 PROTECT PP I END PASS # 1 END PASS # 2 Thanks, John

15 years, 1 month

Nearly there with IBM 029 KeyPunch

by roger.holmes＠microspot.co.uk

The theory said to change the resonant frequency of my keypunch's ferro-resonant power regulator from 60Hz to 50Hz I should up the 15uF capacitor to 21.6 uF. Well I tried 21.5, and the voltage went up by ONE volt. Hmm, scratch head, at least it went in the right direction. Search around for AC capacitors and find one in a defunct large electric lawnmower. Its 30uF, I think about replacing the 15 with it but if an extra 6.5uF only gained one volt, and I need 6 then it seemed reasonable to combine it and try 45 uF. That gives me 46volts, only 2 volts short. I throw in the 6.5uF too and I get 47 volts. I try the punch and it works much better. Not 100%, but that could well be down to other problems. For one thing, the alpha shift key does not latch, I need to hold it down. There are keys for numeric and alpha. If it was not meant to latch, why would they have a numeric key? Its so many years since I used an 029 (at university as my first job was at a paper tape using establishment) that I can't remember for sure. Anyway, thats sounds like an easy problem to find in relay logic, though these wire relays are difficult to see if they are active or not. Maybe I'll add LEDs (and resistors of course). Another problem is 1 to 7 print fine, but not 8 and 9. The alphabet print only their numeric component, 1 to 7 and again not 8 or 9. I tried using it in interpret mode, it fired like a machine gun but the card did not move, but the time I worked out how to stop it there was the smell of overheating solenoids. I don't think I damaged anything, just a bit hot. Thanks for all your help.

15 years, 1 month

Kinda OT: Apollo 11 - The Owners' Workshop Manual • The Register

by woyciesjes＠sbcglobal.net

http://www.theregister.co.uk/2009/06/10/apollo_owners_manual/ ...and... http://www.haynes.co.uk/webapp/wcs/stores/servlet/ProductDisplay?catalogId=… -- --- Dave Woyciesjes --- ICQ# 905818 --- AIM - woyciesjes --- CompTIA A+ Certified IT Tech - http://certification.comptia.org/ --- HDI Certified Support Center Analyst - http://www.ThinkHDI.com/ "From there to here, From here to there, Funny things are everywhere." --- Dr. Seuss

15 years, 1 month

Transistor Substitution

by tshoppa＠wmata.com

Allison writes: > Answer: the 2N2222A (metal can not the plastic PN2222) has the same or close > enough FT, Ic and breakdown voltages. It would be my first choice if I could > not purchase/salvage the exact part. Also the 2n2222A is available and usually > cheap. I buy them usually in for groups of 25 for about $0.08US each. Ethan asks: ? What is different about the metal can and the plastic case part? Mostly lead spacing and cosmetics. Metal can pinouts are in a semicircle, the TO92 is a straight line layout. If the original was a metal can soldered down flat to the PCB, chances are the plastic transistor will be showing some leg if used as a replacement. Metal cans can be heat sinked better than a plastic part obviously, and for peripheral or line drivers heat dissipation may be important. For a while in the 60's and 70's, the metal can parts had superior hermetic seals that were important in some space and mil-spec applications, but since then the plastic packages have been entirely perfected. Tim.

15 years, 1 month

IRC channel?

by jzg22＠drexel.edu

We have an IRC channel (of sorts): Network: Freenode (irc.freenode.net) Channel: #classiccmp -- Jonathan Gevaryahu jgevaryahu(@t)hotmail(d0t)com jzg22(@t)drexel(d0t)edu

15 years, 1 month

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test-drb June 2009