So a friend handed me  PIDP 8 and PIDP 11 kits to build for him today. - Page 1
Forum section: electronics / projects

author: Housedad
author_rank: Frequent Contributor
timestamp: May 09, 2019, 07:48:09 am
content: A very old friend who I have not seen for some time dropped by today. He lives about 400 miles away now so I don't get to see him much.He brought in a tote and said that he had a favor to ask. He had both a PDIP 8 and a PDIP 11 replica kits in there and asked if I would assemble them for him. He felt that his soldering skills and equipment was not up to the task.This is going to be fun. Just the kind of thing I love to do. Lots of through hole!! Seriously, I love to do this stuff.So I'm going to have a bit of fun for the next few days. Back in the day, in high school, we both were about the only kids in our school that bothered to use the PDP-8 that was in the math resource center. We were considered the nerds of the school. At college, we both used PDP-11's. This is going to be a trip down memory lane. playing with the software and flipping switches. Blinky lights at it's best.Here's a link to the site:https://obsolescence.wixsite.com/obsolescence

author: MarkF
author_rank: Super Contributor
timestamp: May 09, 2019, 08:45:28 am
content: Ah. The good old days.We used PDP-11/55s where I worked for many years.

author: rrinker
author_rank: Super Contributor
timestamp: May 09, 2019, 07:39:52 pm
content: I keep looking at those. In college, we had a DEC 20, but I didn't use that very much, the engineering stuff was almost all on the CDC Cyber 730 (upgraded while I was there to an 830). But in my first job post graduation, we bought a piece of equipment controlled by a PDP 11/23 which, with a lot of scrubbing and TLC, I was able to bring fully functional, and in the process learned a lot about RSX/11 which was the OS it was supplied with (the DEC at school had TOPS). Plus I got to use my FORTRAN programming skills to write programs for it. For a while I thought it would be fun to have something similar. Though the 11/23 did not have a full front panel like other models of the 11 series. ANd of course the PDP 8 is a classic as well - I first saw one when they took us to tour the vocational program for school, there was a computer science program of sorts and they had a PDP 8. And I found in the library we used to go to, a pair of PDP 8 manuals, which I checked out and read through several times. All a bunch of nostalgia, perhaps pone of these days I will get one of those PIDPs.

author: westfw
author_rank: Super Contributor
timestamp: May 10, 2019, 06:39:40 am
content: DEC20s were wonderful beasts. "full mainframe" (50-100 users) rather than a minicomputer, and an entirely different architecture than PDP8 or PDP11. I spent the first six years or so of my career doing "systems programming" on DEC20s.Alas, I haven't been very interested in setting up any of the emulators that are available. :-(

author: Housedad
author_rank: Frequent Contributor
timestamp: May 10, 2019, 10:37:19 pm
content: It sure was a long time ago. The PDP8 was high school 1973 through 1976.

author: tocsa120ls
author_rank: Regular Contributor
timestamp: June 22, 2019, 05:56:43 pm
content: Snagged one of the June 5th batch. I have to say this kit is pretty comprehensive.My only complaint would be that using a threaded nut as a spacer is a bad idea. I had to pull the board once, and of course that nut got caught and I turned 2 out of 5 hex spacers back out of the fascia.The other one is the software, specifically the Blinkenbone library they built for it. I have a few Orange Pi's lying around (w. Armbian) and thought about using one to drive the PiDP. Forget it. After 4 hours of trying and recompiling the Blinkenbone software multiple times it would still timeout on the OPi's GPIO. In the end I needed some air anyway so I went and picked up a RasPi.None of these are real problems - the nut is really a 'meh' problem if you have some threadlocker, and it is stated in the description that it only works on Raspbian with a Raspberry Pi.I ordered a bunch of panel-mount cables to patch the Pi's connectors out to the backplate. Also mounted two extra IC sockets for the MAX232 expansion. I plan on using an USB-to-serial converter like a FT232RL... trouble is they have 4 knockouts for serial and 4 for USB... so I probably will design a small panel that has a hub like a USB2504 or a TUSB2046 and the FTDI chip on it.(Or I could invoke my inner Woz and look for a chip that has at least 2 functions built in, instead of using 3 chips in line)

author: IanB
author_rank: Super Contributor
timestamp: June 22, 2019, 06:25:01 pm
content: I've seen a video of someone assembling one of these PiDP-11's.However, when I worked with real PDP-11 computers they had serial ports you could plug terminals like VT100's into and they ran operating systems like RSX-11 or RT-11.If you can't do something similar with a PiDP-11 I'm not sure it would hold the interest for very long. In the video I watched someone was playing around entering a blinking light program through the switches on the front panel, which gave many viewers the impression this was how those computers were actually programmed!

author: tocsa120ls
author_rank: Regular Contributor
timestamp: June 22, 2019, 06:36:46 pm
content: It has both RSX-11 and RT-11 (and SysV and others too) but to connect up a real terminal you have to add hardware.I plan to do it so everything fits in the box and it will be level correct RS232 but if you have an usb-serial converter just try plugging it up, it should work. Also if you log in to the RasPi with ssh you can use screen -x to connect to the emulator like this and you can use it.Default screen is the smaller one, RSX11 is the longer.

author: chris_leyson
author_rank: Super Contributor
timestamp: June 22, 2019, 06:41:32 pm
content: Got to play with a PDP8 40 years ago. You would key in a few instructions using the operators monitor panel to probably jump to a boot loader and then load the program from punched tape.

author: Kjelt
author_rank: Super Contributor
timestamp: June 22, 2019, 08:18:44 pm
content: Quote from: Housedad on May 10, 2019, 10:37:19 pmAh I envy you. In our highschool begin 80's there were still no computers at all