Pacman Board Theory

Pacman Video Circuitry
Theory of Operations

(c) Mark Spaeth 1999

After searching the net for info while fixing a stack of dead pacman boards, I couldn't find any documentation on the video circuitry. This document is an attempt to rectify the problem. Since pacman uses a rotated monitor, the term horizontal will refer to things that appear on the vertical axis and vice-versa, so that the description will match the labeling on the schematics (not just to confuse you).