to create its own chip that would unlock the NES. Tengen announced that they were going to release their own cartridges in December 1988. When Tengen launched the unlicensed versions of its games, Nintendo immediately sued Tengen for copyright and patent infringement. This began a series of lawsuits between the companies which would not be settled until 1994. Tengen faced another court challenge with Nintendo in 1989 in copyright controversy over the two companies' NES versions of Tetris. Tengen lost this suit as well, and was forced to recall what was estimated to be hundreds and thousands of unsold cartridges of its version of Tetris (having sold only about 50,000 copies). Tengen went on to produce games for other systems, including the Sega Genesis, Master System, Game Gear, and TurboGrafx-16, and a few more, as well as publish a localized Sega CD title. The company also licensed games for home computers such as the Amiga and the Atari ST, most of which were published by British company Domark. It was best known for its ports of popular Atari arcade games, including Klax, Hard Drivin', STUN Runner, and Paperboy, although they published many other titles as well. In 1994, with the lawsuit against Nintendo settled and after Time Warner reacquired a controlling stake in Atari Games, Tengen was consolidated into Time Warner Interactive. NES games Tengen manufactured both licensed and unlicensed versions of three of their NES games (R.B.I. Baseball, Gauntlet, and Pac-Man). The cartridges for their unlicensed games did not come in the gray, semi-square shape that licensed NES games came in; instead, they are rounded and matte-black, and resemble the original Atari cartridges. Licensed and unlicensed R.B.I. Baseball (released June 1988; reskinned version of Pro Yakyū Family Stadium by Namco) Gauntlet (released July 1988) Pac-Man (released October 1988; based on Namco's 1984 Famicom port) Unlicensed only Tetris: The Soviet Mind Game (released May 1989) Super Sprint (released July 1989; licensed version released in Japan by Altron) Rolling Thunder (released October 1989; released as a licensed game by Namco in Japan) Road Runner (released November 1989) Vindicators (released November 1989) After Burner (released December 1989; not related to the version released by Sunsoft in Japan which was titled After Burner II) Alien Syndrome (released December 1989; released as a licensed game by Sunsoft in Japan) Shinobi (released December 1989) Toobin' (released December 1989) Fantasy Zone (not related to the version