great! I was waiting for that since forever!!!!
If I'd have known you needed to know, I would've been able to tell you that there were games that need ROM in $f0:8000 since forever

There's a few different sets of boards that behave in a specific manner that results in the impossibility of universal mappings. Whatever route you go, moving away from the binary blob as the sole source of information used to map a game is "very very good"...