This was an electronics project I built using a Teensy++ 2.0 microcontroller. I bought a gameboy cartridge header and soldered breakout pins for it onto a protoboard. I connected this up to my microcontroller on a breadboard and wrote my own firmware for it in C that was able to dump carts and saved games. At the end I was able to upload a saved game from the internet with all 151 pokemon onto my physical pokemon blue gameboy cart.