Since DEUNA works, I more or less constantly have one or more boards running 2.11BSD. One of these has only been down twice since November 2 – the first time after three months when I accidentally touched the power switch while cleaning, and the other time last week when a transformer exploded across the street […]

DEUNA works!

Terasic's de0 board with Digilent's pmodnic100 attached

I already posted that I was working on it, so it should not be a very big surprise. DEUNA now works. At least, it works good enough for 2.11BSD – and very stable as well. I’ve even written a new web server for 2.11 – well, you’ve […]

PDP2011 has been to VCF

Jack Rubin sent me this picture of his DE0 board running RT11 in front of a real PDP11/70. Taken during the VCF East 8.0, which took place last weekend. It’s something of a classic ‘old meets new’ picture – there being something like 40 years of age difference in it. Would have liked to be […]

Fixes and Nexys3

Since the last post I’ve been fixing some more bugs in the new serial controller. The most obvious difference is that it’s speed is configurable now. Less obvious, but equally if not more important, is that the stability is much improved, especially in the rx channel. At the time of the last post, however, a […]

TCP/IP on 2.11BSD

After finding the bug in the MMU details of the JSR instruction, now almost three weeks ago, I thought to spend a lot of time just playing with 2.11BSD and not actively doing any development.

Well, that almost worked. At least, it did until I realized that it would be really great to be able […]

Finding the final bug

Since the 11-11-11 announcement of the project, nothing much happened for quite a while. Or so it probably seems.

Actually, I’ve worked on-and-off (mostly off, to be honest) on the minor, but still very annoying bug in 2.11 BSD – I mean the bug that crashed the C compiler when doing a kernel build.

I […]


I have added a couple of ready to go bitstreams to the download page, for the DE0, DE1, and Nexys-2 1200 boards.

The DE0 image is an 11/45 with an embedded terminal added into the FPGA; just connect a VGA screen and a PS2 keyboard. It has both an RL or RK controller; select which […]

Website is up!


Thanks for stopping by. Information about PDP2011, my VHDL PDP-11 project is in the Pages menu to the left. What you’re looking at now is just a sort of blog that I’ve started today, it will become my diary of updates to the PDP2011 project.

I’m still working to add content to the site, […]