Ah, yes, there was an article here a year back about the original Furby using that same configuration. The article actually had the annotated 6502 source code.

Ah, yes, there was an article here a year back about the original Furby using that same configuration. The article actually had the annotated 6502 source code. https://news.ycombinator.com/item?id=17751599 https://news.ycombinator.com/item?id=17751599