The Apple ][ colour controller

January 4, 2018

Comment from E-mail

I was reading slashdot.org today and I saw someone had posted this comment. Is this true? > “Actually, the Apple ][ color controller was an accident! They didn’t know it was generating colour until one day they connected it to a colour monitor, rather than a Black&White one, and to their surpise, it was colour…so Woz had to reverse engineer his system to figure out how to control it’s colour capabilities.”

Woz

That is so so untrue. I dreamed up the method of using pixels on a color TV screen, based on an exact multiple of the color subcarrier frequency, while constructing a [hardware] game for Atari around 1974. I based my [monochrome] 1975 Apple I design on this frequency, intending to add color ability to it later. When I got down to adding the color, I came up with so many circuit optimizations that I designed the Apple ][ instead.

I used such a simple, patented, scheme to generate color that the circuitry doesn’t show any direct evidence. It’s as though you’d have the same number of chips to generate the video, even without color. But you’d have a tough time explaining a chip or two that gated the color subcarrier frequency during part of the horizontal blanking. It can’t be passed off as an accident. Not to mention that you could never even ‘see’ color on a TV without this subcarrier reference.