Coleco Telstar

The story of the Telstar systems began in 1976. "Telstar", one of the first systems to use the General Instruments AY-3-8500 chip, played only three games (tennis, hockey, handball) with three difficulty levels. It was a huge success with more than a million sold. There was even a variant sold by Montgomery-Ward as the Telstar "Video World Of Sports". A Variation of the Telstar systems based around a newer AY-3-8510 game chip soon surfaced in 1978. It was called the Telstar Colortron. The system offered 4 games, but the picture was in color. Sound was not unpleasant like on most of the other systems, since it came from a little piezzo beeper which produces a very discrete sound.
The game selection is done using a push-button rather than a switch (easier to use and more robust). Curiously, the system requires two 9V batteries: one for the "video" (the games), and one for the "sound" (maybe the internal circuitry of the piezzo beeper
FACT: Telstar video game systems were sold "not fully assembled". The systems themselves were electronically ready to play, but the users had to put the knobs, and stick the decorative stickers on the plastic case. So far, only Coleco is known to have released their systems this way