Transfer Pak

The Transfer Pak is an accessory for the Nintendo 64. It plugs into the slot of the N64 Controller and has a slot for Game Boy and Game Boy Color games to be inserted. This device allows for data to be exchanged between the Game Boy and N64 games. Notable Mario games that use this device are Mario Golf (Nintendo 64) with Mario Golf (Game Boy Color), Mario Tennis (Nintendo 64) with Mario Tennis (Game Boy Color), and Mario Artist: Paint Studio with the Japanese Game Boy Camera. The Transfer Pak allows for specific characters to be unlocked in Mario Golf and Mario Tennis while Mario Artist: Paint Studio allows saved snapshots to be imported or use the camera directly to take new snapshots. The Transfer Pak is the predecessor of the Nintendo GameCube Game Boy Advance Cable.

Trivia

 * Mario Artist: Paint Studio is the only Nintendo 64DD game to use the Transfer Pak; by using the Game Boy Camera.