Sega Research & Development #1 was founded as the first development division within Sega in 1984.
A special team within Sega R&D1 named Studio 128 was founded in 1986.
Sega R&D1 was split into Sega AM1 and Sega AM3 in 1990. Also that year, Studio 128, then named Sega R&D8, became Sega AM2,