I am very confused... I own a 1985 Nintendo and I just learned from the internet that in the game, genie codes can be used. How can I enter these codes in the game?
Thanks you very much if you can help me,
Lizzie177

You are probably thinking of game genie codes. Game genie plugged into the nes like a game then you put the game into the game genie and when you turned it on a code screen came up and you would put in the code. The game genie was just basically a hacking device that would override the games(mario in this case) original coding on the cartride and let you have special abilities in the game.