The PiDP8 has one really neat feature; by setting the first left three white switches, you can control which of 8 boot scripts are used to start the SimH session running the PDP8/I emulation on the Pi.

Oscar provided 8 scripts, from 0.script to 7.script. According to the description file, 5.script is blank. It actually contains assembly instructions for ??? but I just saved that file as 5.script.save, then created a new 5.script which automatically boots the PiDP8 into MULTOS8 maintenance mode if the switches are set to octal 5 = 101.

Here’s my new 5.script:

reset
set cpu 32k
set cpu noidle
att rk0 ../imagefiles/multos8/rsh.rk05
att rk1 ../imagefiles/multos8/multos8.rk05
boot rk1

If you created a running MULTOS/8 system based on my last blog post, you can name the RKA0: disk pack you create to anything you want. I chose rsh.rk05, but any name will do. The .rk05 extension is not mandatory, but appropriate to keep things straight.