The GameBoy is a hand-held game console developed and manufactured by Nintendo and was first released in 1989. It uses a 4 grey scale LCD display and a modified Z80 CPU. The sound card has 2 pulse wave channels, the first with an additional sliding effect, a 32 byte Freewave PCM channel and a noise channel. The speaker is mono but stereo is available through headphones. ROM cartridges varied in size from 256kbit to 8Mbit. The GameBoy remains the most successful hand-held console in history and came originally bundled with the famous Tetris puzzle game.