So I finally got my SMB working on my unisystem! Awesome game. Found some quirks that i'm not sure if it's a problem with my rom version or what.
1. On a two player game, mario and luigi controls are reversed. P1 side is luigi, P2 is Mario
2. When you pop a in to continue, you don't continue, it starts you back at world 1-1 no score but I still have the coins i died with.
3. High scores that are built in when i start are REALLY high. 221,000?! Those are the factory scores?
Other than that, the game is great!