Raspberry Pi PiDP8 Emulator rev 2015
||by Bill Degnan
- 01/10/2017 13:06
The directions suggest two options for setting up your Raspberry Pi OS. I went with option 2, and built a current Debian Linux (Jessie), rather than the pre-configured but older OS Pi SD card ISO (option 1). I followed the directions to install PiDP8 software. Later I also installed Deeper Thought 2 so I could switch back and forth between the two emulators. Both simH and Deeper Thought work on the PiDP8 but never at the same time! The switches have different meanings and will crash if run at the same time.
TIP: First get your Pi networked from the startx GUI (easiest), THEN install the PiDP8 simH emulator. The system should boot into the emulator upon boot even without the front panel attached.
I found having the system boot into simH was nice, but only if I had a keyboard and monitor attached. As a set and forget lightshow the original PDP 8i program called "Deep Thought" is better. Sure enough a few people have already made versions that work on the PiDP. I downloaded Deeper Thought II from the GIT repository and installed it to be the default boot option on my PiDP. Deeper Thought II allows a person to turn off their PiDP-8 by using the front panel switches, slick!
2015 Version Build Instructions:
Deeper Thought 2 (a light show demo)
I used an interior satin base paint for the colored switches, a nut brown color suggested on Oscar's web site.
How to switch from PiDP8 to Deeper Thought:
To jump into the PiDP8 simH that uses the front panel, from a "deeper is currently running" system:
$ sudo systemctl stop deeper
set switches to the version of PiDP8 you want (i.e. from far left 101 111 if you want OS/8...)
$ sudo systemctl start pidp8
$ sudo ./pdp.sh
When you reboot (i.e you intend to go back into deeper thought) be sure to set Sing Step and Sing Inst UP and start and stop UP.
NEVER reboot with both Deeper and PiDP8 enabled or the system will crash and you'll have to rebuild the SD card. There is a diference between start/stop a process vs. enable/disable! Read up on this.
You can check the status of either
$ sudo systemctl status pidp8
$ sudo systemctl status deeper
The command to disable deeper (or pidp8) from loading on boot:
$ sudo systemctl disable deeper
(or disable pidp8)
Here is a Tweet I made as I was working, not quite done:
||by Bill Degnan
- 08/18/2017 16:47
I continue to perfect my PiDP8i setup. At present I have the box booting into OS/8 if one has an HDMI cable/monitor plugged in, by default. One can also have a serial terminal connected, but useterm.sh needs to be run first, to restart the screen so the serial terminal can use OS/8. I fixed a problem with the SSH server, allowing me to access the box remotely. Lastly I updated the RK05 image because ADVENT was not compiled correctly and will not load. I believe the image I got from Oscar's site had issues. Notes to self:
1. Log in using the pi user. The system will attempt to start simh but it will bomb with "There is no screen to be resumed" error. Ignore. Run the following script to
resets screen and dumps directly into OS/8
Wait 10 seconds
CTRL+E to exit to
I also created a shell script to turn off the PiDP and run Deeper Thought. When the system is restarted it reverts back to the PiDP8 systemctrl default.