Oishii Puzzle Ha Irimasenka
Ojanko Yakata 2bankan (Japan)
Olympic Gold (German) (Nova) (MPU4) (set 2)
Ojousan (Japan 871204)
Olympic Gold (Bellfruit) (set 2, UK, 10GBP Jackpot, Protocol) (Scorpion 2/3)
Olympic Gold (Bellfruit) (set 1, UK, Protocol) (Scorpion 2/3)
Oh! Paipee (Japan 890227)
Old Timer (Barcrest) (Dutch, alt 'JPM Classic' sound roms) (DOT1.1)
Old Timer (Barcrest) (Dutch) (MPU4) (DOT1.1)
Olivetti L1 M40
Olympic Gold (German) (Nova) (MPU4) (set 1)
Olivetti L1 M20
Okeah-240
Oigas (bootleg)
Oh My God! (Japan)
Oinori-daimyoujin Matsuri
Ollie King (GDX-0007)
Ojanko High School (Japan)
Oh! Bakyuuun (Japan, OB1/VER.A)
Olympic Gold (Bellfruit) (set 2, UK, 10GBP Jackpot) (Scorpion 2/3)
Consolas
