was released in late 1977. While designing the VCS in 1976, the engineering team from Atari Grass Valley Research Center (originally Cyan Engineering) said the system would have a three-year lifespan before becoming obsolete. They started planning for a console that would be ready to replace it around 1979.

Because of decisions made while designing the VCS, it could not be expanded into a backwards-compatible home computer. Atari developed essentially