Somewhat…successful! So much easier SSHing from main Linux desktop. Can type this post and/or browse the Internet while lengthy sudo apt-get upgrade is running.
After reviewing the docs, in my haste to see some PiDP-11 screen output, I never did the download and install all the PDP-11 various operating systems step. And I think I got an error on the sudo ln -sv libreadline.so.8 libreadline.so.7, although I looked and it appeared that the link was there.
Anywho, After the PiDP-11 software install…I rebooted. I check the screen via the HDMI connection, and it appeared to reboot. However the screen turned black and the cursor was sitting at the top left corner. After a long time (~10min) a mouse pointer appeared on the screen. The pointer would move very slow as if it the CPU was struggling. At this point I attempted to SSH into the Pi, which was also slow. After several minutes it finally accepted the password. but it I hit ENTER it just sat there. After another long time I…
Finally got this on a SSH session…
Going back to the Pi using the HDMI connector…the screen was still black. All these wait times were way beyond what a rational person would assume the install was successful. It was only because I had SSHed into the Pi and would occupy myself doing other things on my main desktop computer, that I continued to wait. I was never able to do the PiDP-11 escape by the CTRL-A d command. I finally was able open another SSH terminal and do a sudo shutdown now.
Some thoughts. It seems to me that the B+ is too underpowered for this. Although one PiDP-11 group member says he runs this same Pi with 8 users. Even the Zero is more powerful than my B+. According to what I read, the B+ has a 700MHz CPU and the Zero has a 1 GHz CPU. Both have 1 core. Model 2 and up have 4 cores. If the CPU is struggling…perhaps using the heat sink that came with my Pi (but I never installed) would help.