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, […]