My student, Zach, got the famous Whetstone floating-point benchmark running in FORTRAN IV on our PDP-12 (results had never been recorded for a '12 without an FPP). He also implemented the Dhrystone integer benchmark in PDP-8 assembly, which (as far as we know) has never been done before. You can read more about it here, and if you have a PDP-8 compatible machine (with or without EAE), you should be able to run his code to benchmark your system! Way to go, Zach! https://forum.vcfed.org/index.php?threads/pdp-8-and-pdp-12-and-dhrystone-and-whetstone.1253367/ #pdp12 #pdp #retrocomputing #umdpdp12 #pdp8

My student, Zach, has been working to debug why our bottom tape unit has been misbehaving. We are fairly certain that the issue is a short in the interface cable between the top and bottom units, because the problem appears on whatever unit is on the end of the daisy chain. Stay tuned. But in the process of monkeying with it, there was a period of time where they both worked just fine! #dec #pdp12 #pdp #retrocomputing #vintagecomputing #umdpdp12

Hi all, we did our annual PDP-12 demo in Dr. Ted Pedersen's architecture class on Tuesday, and it went really well.

In cleaning up / reorganizing after showing off our artifacts, I realized that we have something that I haven't seen on @bitsavers, but I maybe just didn't know where to look. It's a big poster of PDP-12 instructions -- it's kind of like the pocket reference in poster format. It is about 9.5x30 inches (24x76 cm). I scanned it in two pieces on the office machine and stitched it together with GIMP. I'll try to make a PDF version with OCR text. @bitsavers #vintagecomputing #retrocomputing #pdp12 #pdp #dec #umdpdp12

Our PDP-12 (#435) is able to read tapes (but not yet write them). This OS/8 tape is close to 50 years old and still reads well. Here we use the TYPE command to print a long listing stored on multiple tape blocks. LINC and DECtape was able to be used as random access storage (like a disk). The block numbers were written forwards and backwards on the tape so that they could be read regardless of the motor's direction!

In this video, we have a tape mounted on the top drive and have already booted. Zach requests to print the file to the (virtual) teletype, and the blocks of the file are read in sequence.

https://youtu.be/X_GP_L6hK6U

We got the #PDP12 working again! #RetroComputing #RCSRI

PDP-12 demo went great! #pdp12 #pdp #vintagecomputing #retrocomputing #umdpdp12

So my old friend @spacehobo wrote an implementation of Hellorld! for the PDP-12, and getting it to run was quite an adventure. How old of a friend? What's Hellorld!? How quite of an adventure was it it? Watch and learn -- you won't regret it.

https://youtu.be/zcP_Dfgvuo8

(Nick also did a "takeover" of our channel and produced this video, so it is well above our standard sub-standard quality!)

I may have just succeeded in making Usagi Electric's #Hellorld challenge work for the #pdp12. I'll have to wait to see if I can cajole @tastytronic to try this on actual germanium.

A week or two ago, we got Kaleidoscope to run on the PDP-12! We haven't found and repaired any broken flip chips. So, either all the "percussive maintenance" we've been doing in the process of testing flip chips has paid dividends, or -- more likely -- I tried to run it in 8-mode last time... it is a LINC program. Anyway, enjoy these GIFs. #umdpdp12 #pdp #pdp12 #dec #retrocomputing #vintagecomputing #minicomputer

Ever wondered how to turn your 1970s-era PDP-12 minicomputer into a manual musical instrument, kinda like a really crappy theremin? Well, wonder no further! In this video, I provide the source code and performance technique information necessary to do just that! https://www.youtube.com/watch?v=HHepkRo7yRI

My friend @spacehobo saw our PDP-12 wallpaper in the background of one of our videos and wanted a downloadable one, so here's two of them in 1080p. His interest has inspired me to make higher-res versions available in multiple DEC liveries. We also have a special PDP-12 version based on the nameplate at the top of our machine, but it's not ready for the limelight. Enjoy, and stay tuned!

Kyle and I are working to finish testing all the flip chips in the PDP-12 we can test with the FCT (without using an oscilloscope).

https://youtu.be/JWlRkoDxObQ

Forcefield was a performance art group from the late 90s / early 00s. (They had an installation in the 2002 Whitney Biennial and then immediately split up.)

They wanted a shot of one of their weird creatures interacting with an exotic computer for one of their short films, so I brought them into our museum and ran a little graphics program I had written on our #PDP12 for them. (I'm lying on the ground just out of the shot in this, reaching up to twiddle knobs.)

The nameplate on our PDP-12, found inside the case. #umdpdp12 #retrocomputing #vintagecomputer #pdp #pdp12 #dec

While @tastytronic is setting up the new more powerful #dec #flipchip tester (in its snazzy #pdp12 livery!), I went to re-watch the videos about the tester that the #umnpdp12 project uploaded to YouTube. The last one ended with a classic fix (CLEAN THE CONTACTS, LADS) while diagnosing the LINCTape, and they didn't even test the cards before making progress: https://youtu.be/aiHSRF_2bmk

I did a bit of digging into #LINCTape and #DECTape over the past couple years, and so here's a #VintageComputing thread with some of the backstory on these tape formats.

Spoiler: The answer is *always* MIT Lincoln Labs.