GameShark and cheat code books don't exist anymore But back than they sold out fast GameStop had GameShark disc and cheat code books local grocery stores sold books to especially gamepro one of the top gamer magazine books back than use to get them in the mail because of the GameStop membership GameShark had everything infinite health infinite ammo you can go through and destroy every level especially playing resident evil ,medal gear solid mortal Kombat, street fighter and whole lot more cheat code books had simple codes using controller button combination up up down down left right square circle x triangle it depends on what game you where playing