In response to Bretts question about machine compatibility here is a list of machines this board will drop straight into:

1977 to 1985

Bally MPU AS-2517-17

Freedom, Night Rider, Evel Knievel, Eight Ball
Power Play, Mata Hari, Strikes and Spares
Black Jack.

Bally MPU AS-2517-35

Lost World, Six Million Dollar Man, Playboy, Voltan
Supersonic, Star Trek, Paragon, Harlem Globetrotters
Dolly Parton, Kiss, Future Spa, Space Invaders
Nitro Groundshaker, Silverball Mania, Rolling Stones
Mystic, Hotdoggin', Viking, Skateball, Frontier
Xenon, Flash Gordon, Eight Ball Deluxe, Fireball II
Embryon, Fathom, Medusa, Centaur, Elektra, Vector
Spectrum, Speakeasy, Rapid Fire

Bally MPU AS-2518-133

Granny and the Gators, Mr & Mrs Pacman, Baby Pacman
Eight Ball Deluxe Limited Edition, BMX, Centaur II
Goldball, Grand Slam, Midnight Marauders, X's & O's
Kings of Steel, Black Pyramid, Spy Hunter
Eight Ball Deluxe Classic, Fireball Classic, Cybernaut

Stern MPU-100

Pinball, Stingray, Stars, Memory Lane, Lectronamo
Wildfyre, Nugent, Dracula, Hot Hand, Magic
Cosmic Princess (kit)

A further development at Stern resulted in the "-200" board. This Stern MPU used 2 X 5101 RAM so I am unsure about the compatibility
with the Homepin kit MPU? This requires more investigation and I welcome feedback on this.

Stern MPU-200

Meteor, Galaxy, Ali, Big Game, Seawitch, Cheetah, Quicksilver
Stargazer, Nineball, Iron Maiden, Viper, Dragonfist, Flight 2000
Free Fall, Lightning, Split Second, Catacomb, Orbitor One