In addition to the court challenge, Atari Games said Monday that it had replicated the game cassette's computer chip that Nintendo has used to ensure that only Nintendo-made games are played on its machines. Atari Games likened its achievement to developing "the functional equivalent of a key that unlocks the lockout system." The first games that Atari will market on its "clone" cassettes are Pac-Man, Gauntlet and RBI Baseball.