- cctalk - classiccmp.org

by Jim Bender

Does anybody here still use Massbus? Or have a Massbus system you’d like to run, but the idea of dealing with washing-machine disk drives is a bit less appealing these days? In what may classified as a momentary lapse of reason, I have taken up the old Living Computer Museum Massbus emulator project and am in the process of resurrecting / modernizing it. Current progress photo here: http://www.dmv.net/mbe/mbe1.jpg Why, you ask? "Has he gone insane?" are you thinking? I have three PDP-11/70s that I would like to get running again. Sure, I could cheat and hang a UNIBUS SCSI controller with a ZuluSCSI disk simulator, but where is the fun in that? Also, the 11/70 was designed and optimized around Massbus for primary storage, so it seems only fitting to use it that way. The original LCM emulator used a PC with a Mesa 5I22 FPGA card as the Massbus interface. The FPGA implemented the drive-side bus logic, while the PC software emulated the backing disk or tape image. A driver/receiver (“D/R”) board sat in the middle to translate the Massbus differential signals into logic levels suitable for the FPGA. It worked... Since Mesa 5I22 cards are now pretty much unobtainium, I went looking for a cleaner and more modern approach. The result is a redesigned D/R board that accepts a Terasic DE10-Nano directly. The DE10-Nano is a small Linux SBC with a Cyclone V FPGA onboard, so it can host the emulator software itself while the FPGA handles the Massbus interface duties that were previously done by the Xilinx FPGA on the Mesa card. Same general architecture, but much tidier. There is still work to do, but it is coming along nicely. The board in the photo is not yet fully populated, since I am doing incremental testing before committing the rest of the parts. As I have gone down this rabbit hole, naturally a few questions in the “why did they do THAT??” category have come up... paging @Rich Alderson ... If anyone here is still actively using Massbus, has experience with the original LCM project, or just has relevant war stories, comments, warnings, or encouragement, I would be glad to hear them. Cheers! Jim

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Re: Massbus emulation

by Mark Kahrs

At LSSM, we have 2 KS10s and 1 11/70. We have one of the LCM emulators connected to a KS10, but alas, both KS10 power supplies are now deceased, so we are working on replacements. The emulator seems to work fine, for as much as we've used it. Of course, the Massbus connectors are made of unobtanium and must be scrounged from elsewhere.

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VCF East 2026 Post Event Surveys

by Jeffrey Brace

VCF East was quite successful in many ways. Please take a few minutes by answering this anonymous survey: https://www.surveymonkey.com/r/97RMZSJ

1 day, 3 hours

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Ken and Roberta Williams at VCF East (virtually), Wall, NJ April 18, 11AM

by Jeffrey Brace

Ken and Roberta Williams of Sierra Online will appear virtually at VCF East 2026, Saturday, April 18 at 11AM. After a 10 minute introduction, they will take questions from the in-person audience. For tickets to VCF East: https://events.humanitix.com/vcfeast2026?c=cctalk For info: https://whova.com/web/GHMfP%40%40JlCnOF3xlEWLmBBm1POMpM3REEcBH%40BfF1SA%3D/ Take care! Jeff Brace VCF East Showrunner

2 weeks, 1 day

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Re: Kodak Diconix 150plus - looking for info

by Sunil Vadgama

Hello Sir, I have this printer with Parallel Centronics connection. How do I print something using modern pc? Thanks for information on power connection, great help. Thanks Sunil

2 weeks, 1 day

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Bill Mensch will talk at VCF East on April 18 at 5PM in Wall, NJ.

by Jeffrey Brace

Co-inventor of the MOS 6502 microprocessor. He will talk about what he did after leaving MOS Technology Corp. TICKETS: https://events.humanitix.com/vcfeast2026?c=cctalk INFO: https://whova.com/web/GHMfP%40%40JlCnOF3xlEWLmBBm1POMpM3REEcBH%40BfF1SA%3D/

2 weeks, 1 day

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M9301-YA.mac

by Roman Petrov

Dear Noel, Thank you very much for making the M9301-YA.mac file publicly available (https://www.classiccmp.org/pipermail/cctalk/2015-April/006241.html), but I can't download it... When I try to download it, I get the message: "You don't have permission to access /~jnc/tech/pdp11/M9301-YA.mac on this server." Could you please email me the M9301-YA.mac file archive? With best wishes Roman

2 weeks, 2 days

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Lee Felsenstein talk at VCF East on April 19 at 3PM in Wall, NJ

by Jeffrey Brace

Meet Lee Felsenstein will talk at VCF East on April 19 at 3PM in Wall, NJ. A central figure of the legendary Homebrew Computer Club. He is best known for The Osborne 1, The Sol-20, Community Memory. Don't miss the chance to hear from a pioneer who didn't just build the tools, but changed the rules. TICKETS: https://events.humanitix.com/vcfeast2026?c=cctalk INFO: https://whova.com/web/GHMfP%40%40JlCnOF3xlEWLmBBm1POMpM3REEcBH%40BfF1SA%3D/ Take care! Jeff Brace VCF East Showrunner

2 weeks, 2 days

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Tracy Kidder, Author of ‘The Soul of a New Machine,’ Dies at 80

by Christian Liendo

Tracy Kidder, Author of ‘The Soul of a New Machine,’ Dies at 80 A Pulitzer Prize-winning narrative journalist, he wrote deeply reported books that often focused on heroic goodness in people. https://www.nytimes.com/2026/03/25/books/tracy-kidder-dead.html?unlocked_ar…

2 weeks, 4 days

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George Goble passed away

by Christian Liendo

George Goble passed away https://www.legacy.com/us/obituaries/wlfi/name/george-goble-obituary?id=611… From Wikipedia: https://en.wikipedia.org/wiki/George_H._Goble George Harry Goble (December 11, 1952 – March 18, 2026) was an American scientist and academic, who was a staff member at the Purdue University Engineering Computer Network and a 1996 Ig Nobel Prize winner. Goble was commonly known as ghg, since he used that as a login id and signature in digital communications from the 1970s. He received his BS in Electrical Engineering at Purdue University. In 1981, he wired together the backplanes of two DEC VAX-11/780 systems and made the first multi-CPU Unix computer, preceding DEC's dual processor VAX-11/782.[1] The operating system was based on the 4.1 BSD kernel,[1]: 293 and the modifications thus eventually made it into the 4.3 BSD Unix release.[citation needed] At the beginning of the 4.3 BSD user manuals, Bill Joy wrote a special note of thanks to GHG for being courageous enough to put the multi-CPU kernel into a production environment before anyone else did.[2] (However, the frequent crashes for a while inspired the writing of many humorous text files by the Purdue University Electrical Engineering student body, such as "The VAX had a Blowout", to be sung to the tune of "London Bridge is Falling Down".) The development of the Dual-CPU Unix system was the subject of Goble's Master's thesis. Around this time, Goble, along with Bill Croft, also developed a networking protocol for Unix, referred to as pnet, which was used at Purdue at the time before being displaced by TCP/IP. Pnet allowed remote logins, and remote execution of commands, among other capabilities.[3] In the late 1980s, Goble started experimenting with refrigerants, due to increased danger and lower thermodynamic efficiency of the recently introduced R-134a compared to the older R-12 which was being phased out due to concerns about damage to the ozone layer, and the incompatibility of R-134a with the lubricating oil and other materials used in systems built for R-12. In 1987, he converted the beverage refrigerators in the Eta Kappa Nu lounge in the basement of the Purdue Electrical Engineering building to using a refrigerant of his own devising. This refrigerant is now recognized as R-406A by ASHRAE and is available commercially under the trade name AutoFrost. He later developed another refrigerant which is compatible with R134A lubricants, but which is superior in thermodynamic efficiency and lower system internal pressures called GHG-X8. In 1996, Goble was awarded the Ig Nobel Prize in Chemistry, for preparing a barbecue for cooking in less than 5 seconds by the use of a smoldering cigarette, charcoal and LOX (liquid oxygen).[4] This act attracted the attention of the West Lafayette, Indiana fire department, which warned him to never let them catch him in the possession of LOX near a barbecue fire ever again. Goble was also noted for driving a vehicle with the Indiana license plate UNIX, and also GHG-1 https://engineering.purdue.edu/ECE/Alums/OECE/2022/George-Goble

2 weeks, 6 days

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