Nothing technical on my part. I just copied and ran this. From these instructions. FOCAL-69 from paper tape image. Still…as a fan of DEC…cool to see this.
$ pdp8
PDP-8 simulator V3.8-1
sim> load focal69.bin
sim> run 200
_TYPE “HELLO, WORLD”
HELLO, WORLD*
As mentioned from those instructions, several software kits available to run on the PDP-8 and documentation for these can be found on the Simulator Documentation page.
There are also other OSs for the PDP-10 and PDP-11.