[NonNefarious]

The Atari computers (except the 400) had S-video from the very beginning, and the JVC-made Commodore 1702 is a great match for them because it has separate luma & chroma inputs.

Interestingly, LaserDisc players, the best consumer video medium until the late '90s, mostly didn't have S-video outputs because the luma & chroma signals were mixed on the disc; providing a separate output for each wouldn't have gained you anything.

[nicole_express]

I believe the Atari 8-bit computers' CTIA/GTIA chips generate their video output through pins in much the same way as the TIA, with digital luminance and a color output, so it makes sense that S-Video (or I guess I should say "some sort of separated luminance/chrominance", since the S-Video standard didn't exist yet) would be the way to go for a higher-quality picture there.