 The GB Xchanger plugs into a computer in order to copy the games, which can later transfer the game(s) back through the copier to a blank flash cartridge.Early copiers for the Game Boy Advance, Game Boy Advance SP and Game Boy Micro, like the Flash Advance Xtreme are similar to those used for the original Game Boy, as they are external copiers that use parallel ports to communicate with personal computers.The copiers eventually made use of USB with products like first generation XG-Flash carts, which also used external copiers, but benefited from faster write speeds than its parallel port predecessors.