@RObC had a cunning plan, to write a useful ROM to run on a Master which implements efficient sound and video updates from code running on an ARM-based second processor - a Raspberry Pi in this case, running the PiTubeDirect firmware to implement Acorn’s original second processor interface. @RObC has another cunning plan, a hardware board sitting in the Master (or Beeb) to upgrade the video to a colourful palette. With these two plans in place, it’s possible to run C code and to port Doom. The nice thing being that this is all as it could have been back in the day, if only a larger and faster ARM second processor had been available. And if Doom had existed then.
Here’s a thread on exactly how to do it:
Guide to running RobC’s Doom implementation on Master/PiTubeDirect with SD card interface
Here’s the development thread:
Had a very quick look at SDL Doom last night and I really do think that this would be a quick route to getting Doom up and running on the Pi co-pro…
Here’s the first light video:
It seems you don’t need a Master - a Beeb will do:
Here’s a demo of the VideoNuLA upgrade board: