I have always been a fan of DEC Minicomputers.
Not because I have used them a lot (despite what the guys at work think I am a bit too young for that) but as a teenager in the 1980s playing with microcomputers I spent a lot of time dreaming about those machines in my collection of DEC product catalogs.
My father worked for the Physiology Department of the School of Medicine, University of Auckland from the early 1970's until he retired in 1995.
The first computer I ever saw was the PDP8e that he had at work. I don't recall any many of the specifics of the machine except that it was huge (what wasn't when you were under 10), had really cool blinking lights on the front panel and printed me a snoopy calendar when I visited on one of the department open days!
John P Quinn - Physiology Department, Medical School, University of Auckland circa 1975 with PDP8e
While I was studying at the University of Auckland in the late 1990's I visited the my father at work and spent a lot of time using the department machines while I was waiting for my ride home. Even in the 1990's the PDP8e was still operational and lived in a little "computer room".
From memory it had been expanded beyond what was shown in the photo. It still had the TU56 tape drive but I vaughly recall disk storage as well.... likely an RK05J and an LA36 DECWriter printing terminal. I am not sure what the machine did at that point in it's carreer having been replaced for many lab tasks with a mix of Apple II, BBC Micro and MDL S-100 Bus machines.
It was still a very impressive looking machine with the blinking lights and front panel switches. I wonder what happened to it?
Fast forward to 2012 and having completed the Z80 machine on prototype board I was looking for another construction project.
In 2003 Bob Armstrong's Spare Time Gizmos produced a PDP8 compatible single board kit computer (SBC6120) and companion front panel (FP6120). The kits had been out of production for many years but Bob had very generously published all the design files on his web site. If I would build a Z80 on prototype board surely I could build a PDP8. It didn't look too hard and someone else had been crazy enough to try (http://juliepalooza.8m.com/sl/pdp8e.htm). I even found a source for the HD6120 CPU.
I posted an enquiry on the Yahoo Groups SBC6120 group before I kicked off the process to see if anyone had comments on the practicality of building the machine this way.
The result was contact from a group member and a very generous opportunity to acquire an unbuilt kit. Not something I ever imagined possible.
I took my time working through the build process on the SBC6120 from October through December 2012.
Having one opportunity to build this kit I was determined to build it to the highest possible standard. That mean't ordering the original parts specified for the kit rather than trying to substitute parts from the junk box. Sometimes this was expensive, particularly "mechanical parts" like the IC sockets, reset switch and indicator LED's but the result was well worth it.
The following are a series of images showing the SBC6120 through the construction stages.....
SBC6120 PCB and partial parts kit as supplied by Spare Time Gizmos.
SBC6120 PCB populated with machined IC sockets, passive components and sockets.
Operation SBC6120 with Compact Flash Adaptor
Note: Indicator LED's and Stacking Header not installed.
SBC6120 with Compact Flash and 5V switching supply under test
SBC6120 showing J10 CPREQ jumper. Needs to be replaced for connection to FP6120