Sega Corporation personal computers: SC-3000 (1983), TeraDrive (1991) and Amstrad Mega PC (1993).
The SC-3000 (Sega Computer 3000) is the first computer to be designed and manufactured by Sega. It was first released in July of 1983 in Japan, and serves as the home computer equivalent of the SG-1000 cartridge-based video game console. The SC-3000 is an 8-bit home computer almost identical in nature to the SG-1000, but with a built-in keyboard and support for more hardware expansions.
The TeraDrive is an IBM PC compatible system with an integrated Mega Drive, developed by Sega and manufactured by IBM in 1991. The TeraDrive allowed for Mega Drive games to be played the same time as the PC section is being used, as it is possible for the Mega Drive and PC hardware to interact with each other.
The Mega PC is a computer manufactured and released by Amstrad in 1993 under license from Sega. It was similar but unrelated to the Sega TeraDrive. It is a standard Amstrad PC with Sega Mega Drive hardware bundled inside; the system was wired to share the dual-sync monitor and speakers with the Mega Drive on a separate circuit board.