2/3 of the multitap games I analyzed share the same code…
I didn’t understand why until I added ‘Multitap – Sample IO program’ rom to my list of to-analyze-game.
I think they use a code shared by Sega, but what is fun is that they used it like this…including mouse detection / reading code 😉
The code is a little complex, because of the protocol to communicate with the MultiTap.
The EA4Way is far easier to handle !