Heh. Unfortunately that demo only runs on 12" "CRTC" PETs. ;^) (Mine's a nine-inch, which lacks a programmable video circuit. No hardware special effects are possible beyond flicking between character sets.)
I just got it to recognize all 32k of RAM today. If I can nail a small video corruption issue and get a storage device working I'll be frighteningly close to have fixed the silly thing.