The Nintendo Game Boy was a handheld video game console, introduced by Nintendo in 1989 (reaching Europe in 1990).
It competed with other handheld devices such as the Sega Game Gear, Atari Lynx and the NEC TurboExpress that offered colour screens compared to the original Game Boy’s monochrome display. Despite this, the Game Boy outsold them all. This was partly due to the popularity of the puzzle game Tetris that came bundled with the Game Boy.
A smaller, lighter variant, the Game Boy Pocket was released in 1996, and in Japan a variant called the Game Boy Light was introduced in 1998, that included a backlit (but still monochrome) screen.
The Game Boy was superseded by the Game Boy Color in 1998, and was discontinued in 1999. Cartridges (called ‘Game Paks’ by Nintendo) for the original Game Boy could be used in the Game Boy Color.
Some Game Paks contain a small battery to allow game data to be saved. A notch on the top of the cartridge allowed the power switch to lock the cartridge in place while the unit was switched on. Cartridges designed specifically for the Game Boy Color lacked this notch so they could not be used in the original Game Boy.
When the Game Boy Color was introduced, a third type of cartridge was introduced that could be used in the Game Boy, but would also play in colour on the Game Boy Colour. These cartridges (known as dual-mode or class B) were usually black and the same shape as Game Boy cartridges.