Hah, neat to see the 32016 mentioned, I still have a pre-production series sample of that chip somewhere in storage.
Super cool this, I'm almost tempted to score a Master or a Model-B on ebay or mp to replicate this but there just isn't time enough in the day to get sucked into retro computing. Extra points if they ever manage to port the basic to the native Pi including inline assembly, that would be a pretty neat environment to develop stuff for the Pi in.