test-drb May 2021

test-drb@ccmp.vtda.org

128 participants
102 discussions

DEC PDP-8/e Omnibus backplane lubrication

by ccth6600＠gmail.com

What is the best type of lubricant for Omnibus backplanes? It can be a struggle to insert and remove PDP-8/e boards into the Omnibus. There is a risk of damage to the brittle bakelite connector housings on the Omnibus PCB. Traditional contact sprays should work but have two problems: 1) they remain wet and over time will attract and retain dust 2) the solvent and lubricant *may* weaken or attack the bakelite There are some PTFE (Teflon) based lubricant sprays which create a dry film. Would this type of spray work? Any suggestions on what I could use that reduces the strain on the Omnibus and the PCBs during insertion/removal without creating new problems? Thanks and best regards Tom Hunter

3 years, 7 months

Looking for VAXSET Software Engineering Tools for VMS 4.x

by mdehling＠gmail.com

Dear all, I am looking for a version of the VAXSET Software Engineering Tools to run on (Micro)VMS 4.7. The oldest version I have found so far is VAXSET010 which requires VMS 5.3 to run (this was on CSD 1991/05.) VAXSET is a bundle of the following components (and more in newer versions): - CMS (Code Management System) - LSE (Language Sensitive Editor) - SCA (Source Code Analyzer) - MMS (Module Management System) - PCA (Performance Coverage Analyzer) - DTM (DEC/Test Manager) I have found versions of CMS and MMS seperately that run on VMS 4.x. If anyone has old versions of the other components and is willing to share, that would be much appreciated :-) Cheers, Malte -- Malte Dehling <mdehling at gmail.com>

3 years, 7 months

920M - an European contemprary of the Apollo Guidance Computer

by erik＠baigar.de

Dear colleagues in vintage computing ;-) In the last years there has been substantial interest in the Apollo Guidance Computer (AGC). So maybe someone might be interested what happened outside of the United States in the 1960ties: Over the last few years I restored a 920M computer which was (among others) used as the guidance computer in the Europa rocket. This was the ancestor of the European Ariane sapce launcher: https://en.wikipedia.org/wiki/European_Launcher_Development_Organisation Although not well known, this machine is a contemporary of the AGC, it also uses integrated, SMD mounted circuits and is realized in DTL techology (Diode Transistor Technology). Its word width is 18bit, 8k of core store where standard within a show-box sized chassis. 2us and later down to 1us instruction time where stadnard. In contrast to the AGC, this machine was a member of a whole series of airborne computers - some of which are still in use TODAY (2021). After core and the DTL chips became obsolete, this architecture even was re-implemented by BAE systems using the AMD29XX chipset in the same chassis as drop-in replacement. The 920M never had core rope memory, and for rocket guidance 8k have been enough although adding a 2nd box extending the core was possible. Tte architecture is able to support up to 256k words of 18 bit. Of course, the instruction set is very archaic - no carry flag, no stack but it served its purpose with 18 bit choosen as the perfect word length to give reasonable resolution without need for double-word calculation in most applications; http://www.programmer-electronic-control.de/Elliott920FactsCard.pdf If this triggered some interest, you may watch my recently released video on the 920M (covers applications, internals and some software is shown running)... https://www.youtube.com/watch?v=v-gF5g0nnoE ...or visit my project page regarding the work of restoring three different members of this computer family to working condition: http://www.programmer-electronic-control.de/index.html Happy computing to all of you, best wishes, Erik. P.S. Just wanted to point out, that also in Europe there have been relevant developments regarding spaceborne computing in parallel to the Apollo programme! In no ways I want to diminish the achievemets of the Apollo development team... ''~`` ( o o ) +------------------------.oooO--(_)--Oooo.--------------------------+ | Dr. Erik Baigar Inertial Navigation & | | erik at baigar.de .oooO Vintage Computer | | www.baigar.de ( ) Oooo. Hobbyist | +---------------------------\ (----( )----------------------------+ \_) ) / (_/ Dr. Erik Baigar Scientific Lead Spectroscopy Systems Technologie Team Spectroscopy THORLABS GmbH M?nchner Weg 1 85232 Bergkirchen Germany Tel.: +49 (0) 8131 5956-40147 Fax.: ?+49 (0) 8131 5956-99 Mail: ?EBaigar at thorlabs.com Web: ?www.thorlabs.com General Manager: Dr. Bruno Gross HRB No: 85345, M?nchen

3 years, 7 months

MOPPY.....

by organlists1＠sonic.net

Which is closer to being vintage, the sounds made, or the floppy disk drives themselves? Moppy + Star Wars Theme = Floppy Vader's Theme https://youtu.be/LdgzsF_O7oI Donald R. Resor Jr. T. W. & T. C. Svc. Co. http://hammondorganservice.com Hammond USA warranty service "Most people don't have a sense of humor. They think they do, but they don't." --Jonathan Winters

3 years, 7 months

LK201 emulator for PS-2 keyboard

by paulkoning＠comcast.net

Last year I created an LK201 keyboard emulator that uses a USB keyboard. More recently I extended that work to create a second one that uses a PS-2 keyboard instead. Partly because I had one and figured it would be fun to try. You can find both designs on Github at https://github.com/pkoning2/lk201emu . The "doc" directory describes both; in particular, file doc/kicad.md talks about the hardware design, with pointers to an OSHPark layout, a parts BOM, and assembly instructions. The new one is slightly larger than the old (2 by 2 inches, rather than 2 by 1.5). I like the audio implementation a bit better; perhaps I'll revise the USB version to use that same technique. Enjoy. Comments and feedback will be much appreciated, either by email or on this list or as "issues" on Github. paul

3 years, 7 months

Has anyone heard from Paxton Hoag ?

by aek＠bitsavers.org

Josh and I have been trying to contact him for a couple of years now. Has anyone been in contact with him?

3 years, 7 months

PDP-11 SPACEWAR running again!

by mattislind＠gmail.com

Today I finally got the SPACEWAR version for PDP-11/10 running again on my PDP-11/05 with AR11 board. I played a couple of rounds together with my daughter. She was better than me. Quite hard game IMHO. https://youtu.be/fTiHRAKjyho Bill Seiler and Larry Bryant wrote this version in 1974 and submitted it to DECUS. It was believed to have been lost to history. But Bill had saved the printouts from the PAL11 assembler. He sent me scans of these printouts as pdf files. I then transcribed it into source files and iterated several times in SimH to get a clean build and link. I got some help from people here doing OCR on some files. But the lines mostly confused the OCR process so a lot of errors was introduced. It turned out that it was easier to just transcribe the whole lot by hand than finding and correcting errors. The AR11 is somewhat different to the AD01 and AA11 that Bill and Larry used. AA11 has a 12 bit 2?s complement D/A while the AR11 is only 10 bits and not 2?s complement. I did some patches and eventually got everything right. I also connected a couple of analogue joysticks. The fire button is just short ciruiting the viper of the potentiometer to the 5V supply lead. The screen is a HP1332A vector screen. All the transcribed code, AR11 patches and build instructions are available on github. https://github.com/MattisLind/SPACEWAR It should be possible to adapt it to orher types of A/D and D/A hardware if anyone wishes to do so. However the gameplay might be harder when running on a faster PDP-11? Have fun! /Mattis

3 years, 7 months

Apple II PSU

by nospam212-cctalk＠yahoo.com

Anyone have any idea on how to open this particular Apple II PSU? It is a Astec AA 11040B and has like a rivet on each side in the middle. All the other supplies I've messed with just had screws along the bottom. Trying to remove the bottom of the casing so I can work on the supply itself. Link to a pic of it. Thanks for any help. http://www.trailingedge.com/images/A2PSU.jpg David Williams www.trailingedge.com

3 years, 7 months

DMC integral modem line card schematics

by paulkoning＠comcast.net

Does anyone have a DMC11 integral modem line card schematics set? I'm looking specifically for the part right next to the connector, i.e., the coax driver and coax receiver parts. I don't see it on Bitsavers. That does have a line unit maintenance manual which has a schematic of the digital parts (in other words, everything up to the point I actually need the most) but it omits the analog part, saying to find it on "print D16". The DMR11 print set does show a circuit for this, but it's very different from what the DMC manual describes and it has some aspects that don't make much sense, like a "sine generator" in the output stage. paul

3 years, 7 months

Restorations...

by lbickley＠bickleywest.com

Jim, I sent you an email to your jwsmail at jwsss.com mail account and haven't heard back from you, so thought I'd better try to reach you on cctalk! It's about potential restoration work needed in the LA area. Please get back to me privately. Sorry for the interruption of posting this to the cctalk list... Best, Lyle -- 73 NM6Y Bickley Consulting West https://bickleywest.com "Black holes are where God is dividing by zero"

3 years, 7 months

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test-drb May 2021