The Atari 2600 or Atari Video Computer System (VCS) is a video game console released in September 1977. The 2600 runs a MOS Technology 6507 CPU and uses ROM cartridges for storing games.
kenney3295, they are around but they are getting harder to find. You do want to check places like this one. Otherwise I'd check mouser.com or digikey.com as well as many other places for a DB9 connector. Take the measurements from yours and see if you can match it up.