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).
#UmfPdp12 #pdp12 #pdp #dec #RetroComputing #VintageComputing #FlipChip
Special bonus: a picture of a double-wide M706 (rev. K) teletype receiver card under test.
#umdpdp12 #RetroComputing #VintageComputing #DEC #pdp #pdp12 #FlipChip
Finally, here's a glam shot of the FCT with an M617 installed. Thanks for joining me on today's project! Special thanks again to @neale and @ckape for the hardware donation, which saved this shoestring project close to $200.
Major thanks to Vince Slyngstad for producing Warren's design, making it RPi-compatible, and making a 3D-printed base -- not to mention selling me this kit pre-assembled -- this is a pretty sweet package and will go a long way towards helping us keep the our PDP-12 up and running for years to come.
If you're interested in learning more about our PDP-12, or donating to the fund supporting this project, please see https://umdpdp12.blogspot.com/ or check out our videos on YouTube: https://www.youtube.com/playlist?list=PLHnc49MScQBBIlVIirpZ1Zjdh91U5Q6-6
#umdpdp12 #RetroComputing #VintageComputing #DEC #pdp #pdp12 #FlipChip
Here's a video of the tester running a "fail stop" test -- testing the chip over and over again, stopping only on a failure.
#umdpdp12 #RetroComputing #VintageComputing #DEC #pdp #pdp12 #FlipChip
It works! Here's a picture of the fully assembled unit, with an M617 in and powered, and a successful test on the screen behind it.
#umdpdp12 #RetroComputing #VintageComputing #DEC #pdp #pdp12 #FlipChip
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.
We like retro-computing and we like open source standards that allow easy project sharing. Vintage DEC computer enthusiast [Jay Logue] combines both of these in his recent project on GitHub, where he shares several KiCad templates for making your own Flip-Chip modules. Although named after the semiconductor packaging technique we are familiar with today, DEC Flip-Chips were introduced in 1964 as a modular electronics packaging system. These were used in many of DEC's Programmable Data Processor (PDP) computers, beginning with the PDP-8 in 1965. DEC also had a Digital Laboratory Module family, which was a roll-your-own custom electronic system. The 1968 Digital Logic Handbook shows the available modules, and has the look and feel of the TTL Cookbook book which would come along six years later.
Flip-Chips came in a variety of sizes over the years: single-, double-, and quad-, and hex-height boards having standard- and extended-length. The PCB's have 18 gold-plated fingers on one edge, later extended to 36 fingers double-sided, which plug into a backplane. Interconnections were typically wire-wrapped. A single height board is 127 x 62 mm (5 x 2-7/16 inches) with a labeled extractor bracket on one end. [Jay]'s repository has templates for five of the most popular variations, and making other sizes should be straightforward using these templates as a starting point.
While we pack a lot more functionality in similarly-sized circuit boards these days, many systems still use a modular design not unlike the Flip-Chips from over 50 years ago. Do you have any recollections of using Flip-Chips, or are you using them today? Let us know in the comments below.
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