If you are looking at a physical cartridge to dump your own ROM, you can identify the version by the "punch code" (a small number stamped into the back label): Two digits only (e.g., 00 or 19 ). 1.1: Two digits followed by "A" (e.g., 19A ). 1.2: Two digits followed by "B" (e.g., 19B ). Modern Usage and Compatibility