pemdawg wrote:
Would this be possible? If the two games are unchanged beyond the game select menu, couldn't one feasibly insert data for different NROM games into it?
That's possible, but doesn't really save you much. You'll still need to both draw new menu items and modify the games to return control to the menu on power-up (The version of SMB in this multicart 'MHROM' differs in the 2nd through 9th bytes from the non-multicart version)—otherwise the SMB-replacement stands a 50% chance of running instead of the menu. You might consider starting with something like mapper 41 (Caltron 6-in-1) instead.