Namco Pac-Land

The Namco Pac-Land was an 8-bit arcade game system board which was first used by Namco in 1984; the second and fifth games to run on it, Dragon Buster and Sky Kid, are modified to support vertical scrolling, and the third and fourth games to run on it, Metro-Cross and Baraduke (also known as Alien Sector), are modified to support a 2048-color palette. Baraduke was also the only game from Namco to use their programmable sound generators for speech.

...
Wikipedia