Editing Intellivision (section)

===Entertainment Computer System (ECS)===
{{Main|Entertainment Computer System}}
[[File:Intellivision ECS module.jpg|thumb|Entertainment Computer System with Keyboard and Power Supply]]
In mid-1981, Mattel's upper management was becoming concerned that the Keyboard Component group would never be able to produce a sellable product. As a result, Design and Development set up a competing engineering team whose stated mission was to produce an inexpensive add-on called the "Basic Development System", or BDS, to be sold as an educational device to introduce kids to the concepts of computer programming.

The rival BDS engineering group eventually came up with a much less expensive alternative. Originally dubbed the "Lucky", from LUCKI: Low User-Cost Keyboard Interface, it lacked many of the sophisticated features envisioned for the original Keyboard Component. Gone, for example, was the 16K (8MB max) of RAM, the secondary CPU, and high resolution text; instead, the ECS offered a mere 2KB RAM expansion, a built-in BASIC that was marginally functional, plus a much-simplified cassette and printer interface. Ultimately, this fulfilled the original promise of turning the Intellivision into a computer, making it possible to write programs and store them to tape as well as interfacing with a printer. It even offered, via an additional sound chip ([[General Instrument AY-3-8910|AY-3-8917]]) inside the ECS module and an optional 49-key music synthesizer keyboard, the possibility of turning the Intellivision into a multi-voice synthesizer which could be used to play or learn music.

In the fall of 1982, the LUCKI, now renamed the Entertainment Computer System (ECS), was presented at the annual sales meeting, officially ending the ill-fated keyboard component project. A new advertising campaign was aired in time for the 1982 Christmas season, and the ECS itself was shown to the public at the January 1983 [[Consumer Electronics Show]] (CES) in Las Vegas. However, it would not see release until late December as the ''Intellivision Computer Module''.<ref name="B&S2024_264">{{cite book |last1=Boellstorff |first1=Tom |title=Intellivision: How a Videogame System Battled Atari and Almost Bankrupted Barbie |last2=Soderman |first2=Braxton |date=2024 |publisher=MIT Press |isbn=9780262380553 |page=264}}</ref>

Prior to release, an internal shake-up at the top levels of Mattel Electronics' management had caused the company's focus to shift away from hardware add-ons in favor of software, and the ECS received very little in terms of furthering the marketing push. Further hardware developments, including a planned Program Expander that would have added another 16K of RAM and a more intricate, fully featured Extended-BASIC to the system, were halted. In the end, six games were released for the ECS; a few more were completed but not released.

The ECS Computer Module also offered four player game-play with the optional addition of two extra hand controllers. Four player games were in development when Mattel Electronics closed in 1984. ''World Cup Soccer'' was later completed and released in 1985 by Dextel in Europe and then INTV Corporation in North America. The documentation does not mention it but when the ECS Computer Adapter is used, ''World Cup Soccer'' can be played with one to four players, or two players cooperatively against the computer.