A Division of
Atari Games which was formed in the late
eighties to develop games for various home game
consoles, Tengen reached a bit of infamy when, after releasing four "legal"
NES titles, they developed a work-around for
Nintendo's lock-out chip, cancelled their developement contract with N, and began manufacturing unlicensed NES games on their own.
As you can imagine, Microsof... er -- Nintendo -- didn't like this very much. The typical lawsuits ensued.