Sega Mark III

The original 1985 Japanese model, third in the SG-1000 line and the hardware basis of the Master System.

The Mark III launched in Japan on October 20, 1985 for ¥15,000 as the third version of the SG-1000 line. It was built by the same team as the SG-1000, including Hideki Sato and Masami Ishikawa. According to Sato, the redesign happened because the Texas Instruments TMS9918A graphics chip could not handle the games Sega wanted to make, so an in-house chip was designed around the System 2 arcade board.

It measures 318 × 145 × 52 mm and, with few exceptions, its hardware is identical to the Master System's. It plays SG-1000 and SC-3000 cartridges as well as cards; its first dedicated games, Teddy Boy Blues and Hang-On, came out on cards on launch day. The FM sound chip was optional, and the 3D glasses needed an extra converter. Despite being more powerful than the Famicom, it was not a success.