Sega Master System / Mark III / Game Gear
The Sega Master System was a game console released in 1985 in Japan, as the Sega Mark III, 1986 in the US, 1987 in Europe, and 1989 in Brazil. Being an mid-1980s Console, the Master System mainly competed with the Nintendo Entertainment System, and the Atari 2600 and 7800.
The Sega Master System was released in 1985, as the Sega Mark III, to compete with the Nintendo Famicom(The NES in other regions).
The Sega Mark III and Master System had a Z80 CPU running at 3.58MHz.