Pac-Man makes a cameo in Tron.
I remember people mentioning the Pacman cameo, but I only heard the sound effects from the game, but not the actual appearance. I guess some people in Disney were fans of the game. It is kind of ironic that the Tron game would share space in arcades with Pac-Man later on.
They mention the Pac-Man thing in the Nostalgia Chick review of Tron.