I know this is an old thread, but I believe I have both versions of the Indy cart.
I have the TTL mainboard, but both carts work. They have different ROM numbers though.
If I wanted to convert one of the carts to Marble Madness, would it be better to convert the TTL or LSI cart, and has anyone done this before?
It would be nice to document the different main boards, and their compatibility with various carts, and what's needed to convert between them successfully. Some of that has already been discussed here.
That said, if anyone has a working MM cart, I have a working Indy cart if anyone wants to trade.
Thanks!