For the 6-character codes, whenever the address referenced by the Game Genie code is accessed, a specific data byte is returned. Both these types of codes translate into a 15-bit address in the game ROM (from 0x8000 to 0xFFFF for the 6502-based NES) and a data byte. There are two varieties of Game Genie codes – 6-character codes and 8-character codes. There is, of course, a rhyme and reason behind the Genie and put together a great walkthrough of how the Game Genie works.
To someone who doesn’t yet know where the 1-up is in the first level of Super Mario Bros., the Game Genie seems magical. Those of us old enough to remember blowing into cartridges will probably remember the Game Genie – a device that plugs in to an NES, SNES, Sega Genesis, or Game Boy that gives the player extra lives, items, changes the difficulty, or otherwise modifies the gameplay.
