Expansion Module No. 1 allows all cartridges compatible with the Atari 2600 VCS to be played on ColecoVision console. When the Expansion Module is plugged into the Expansion Module Interface, the widest possible library of video game cartridges can be played on the ColecoVision system.
Alternatively, existing Atari owners can purchase the ColecoVision videogame system and still make use of their existing software library. Game play can be controlled using ColecoVision game controllers which plug into the Expansion Module No. 1.