Master System:Master System Mods Wiki
The Sega Master System is an 8-bit console from the third generation of video game consoles. Originally released on October 20, 1985 as the Sega Mark III — the third revision of the SG-1000 — the Sega Master System was later released in North America (September 1986) and Europe (June 1987). It offers backwards compatibility with the full SG-1000 library on Sega Mark III and Japanese Master System units. A later revision, the Master System II, was released in 1990 in North America and 1991 in Europe, Australia, and Asia.