Finally, I’ve managed to find the time to finish up the new boot code, test everything, generate new bitstreams for the download page, and update the site.
There are now two different sets of boot roms to choose from. The sources in m9312l46.mac and m9312h46.mac are the – now almost unchanged – DEC M9312 boot […]
Last November, Scott Swazey asked why I made my own boot loader instead of using the original M9312 code.
I knew that the sources for M9312 were available, and I did have a look at them a long time ago. At that point, I was not sure I would ever get the CPU running, let […]
Over the last months, I had a couple of occurrences of the problem where 2.11BSD would loose it’s network connection, reporting that there were no transmit buffers available on the DEUNA. All in all, I’ve seen this problem three or four times over the last year, but maybe ten times in the last month or […]
A couple of weeks ago someone mentioned that there were some FPGA related articles in the December issue of Circuit Cellar. So I checked it, and one of the articles pointed me to the built-in logic analyzers that the leading tool chains now all seem to have. At least, the Circuit Cellar article is about […]
Last week Al Kossow posted some new sources for XXDP tests on Bitsavers. Included are the sources for the MMU tests for 11/34. I tried to run those, and was surprised by a list of error messages… Turns out, there were a number of issues left in my MMU implementation, that none of the other […]
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 […]
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 […]
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 […]
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 […]
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 […]