TIA 1A - TELEVISION INTERFACE ADAPTOR (MODEL 1A)
10. Color Phase Shifter
This portion of the chip (shown in figure 3) produces a
reference color output (color burst) during horizontal
blank and then during the unblanked portion of the line it
produces a color output shifted in phase with respect to
the color burst. The amount of phase shift determines the
color and is selected by the four color code lines from the
Color-lum multiplexer. Binary code 0 selects no color.
Code 1 selects gold (same phase as color burst). Codes 2
(0010) through 15 (1111) shift the phase from zero through
almost 360 degrees allowing selection of 15 total colors
around the television color wheel.