[Alex] collects retro gaming consoles. One day while playing a SNES title, his save games got wiped when he powered off the system. It turned out that the battery inside the game cartridge got disconnected somehow, and it got him thinking. He decided he wanted to find a way to back up his save games from the cartridges for safe keeping.
While cart readers exist, he says that they are hard to find nowadays, so he decided to construct his own using an Arduino. SNES cartridges are relatively complex, so he opted to focus on Gameboy cartridges for the time being. Before attempting to back up save games, he first chose to learn how to communicate with the cartridges in general, by reading the ROM.
He breaks the cartridges down in detail, discussing how they are constructed as well as how they can be addressed and read using the Arduino. He was ultimately successful, and offers up code as well as schematics on his site for any of you interested in doing the same. We imagine that save game reading (and perhaps editing) will likely happen in the near future.
Check out the video below to see his cart reader in action.