DEC Legacy 2021 – Windermere, 9th-10th October

After a long wait we finally got to do the next DEC Legacy this weekend. It was started in 2010 and is run on a semi-regular basis and it is something I look forward to every year. There were fewer people this year as some people could only attend remotely, but it was great to see many familiar faces.

MicroVAX II with VT220, Teletype and VAXstation 3520

As usual, the first thing I saw was Matt’s van:

Matt brought a PDP 11/84 which was of course the star of the show:

I decided to bring less stuff this time because I always bring too much. So I kept it to the following:

  • A MicroVAX II with a VT220 terminal.
  • A Teletype Model 33 ASR connected to SIMH running TOPS-20.
  • A VAXstation 3520, configured as a 3540.
  • A DEC 2000 Model 300 (aka Jensen).
  • The David Gesswein MFM emulator.

I first got the VAXstation 3520 going. I have installed PHIGS and ran the demo program. Craig showed me some of the DEC Windows example programs. It was interesting to see how the ICO program really slowed down when the PLAID program was also run and made a bit bigger. It was an amazing contrast to see the same ICO program running on the Jensen, where it ran massively faster.

Later I ran my user mode DECnet router on my laptop while Matt run a SIMH VAX router on his laptop and we networked from my VAXstation to his PDP 11/84 running RSX. Matt has a program written in Coral that draws fractals using ReGIS. We ran it from a DECterm session on my machine and it displayed perfectly. Sadly I didn’t get a picture of this. To get to this point we had to get around the fact that the machine didn’t seem to see the network. On Matt’s suggestion I toggled the thinwire/AUI selector switch and that seemed to do the trick.

I ran the TOPS-20 emulation on my laptop and connected it to Teletype using reverse Telnet via a DECserver 90M and a Westermo Current Loop converter. We ran some simple programs in BASIC-PLUS-2.

My MicroVAX II would not start up. I found that the RD54 was not spinning up. I tried various taps on it to make it go but nothing worked. Craig suggested twisting it in a circular motion and this did the trick. After that the MicroVAX II ran nicely.

Bob brought an RD54 to give me. He said it has RSX on it so I brought along the David Gesswein MFM emulator in order to image the disk first. The disk seemed to work first time and we imaged it. I will try the disk in a PDP 11/73 I have at home.

Chris and his Dad spent a lot of time with Jensen trying to find out why his wasn’t working by comparing it with mine, which does work. Mine wouldn’t start at first, it seems the disk was not spinning up. Again Craig worked his magic and got it spinning. In the end it seems Chris’s machine had a combination of bad RAM and bad SCSI cable. We didn’t get it fully working, but I think they know how to get it working now. I learned from Chris’s Dad that the Jensen is called that because one of the managers responsible for it was mad on cars and had a Jensen!

The event was livestreamed, I think the links are here:

Stream from Day One
Stream from Day Two

Thank you Mark for organising this year after year and for arranging for some interesting talks. I am looking forward to seeing more people in person next year and maybe I will be able to bring my PDP 11/24.

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