nonlinear waves in cellular automaton

Cellular automaton that mimics oscillating reactions like Belousov-Zhabotinsky one in excitable medium
http://www.ibiblio.org/e-notes/webgl/webgl.htm
One 9kb script shows spiral and random waves ~20fps on HD 4650 in the 512x512 window. If you have any questions or suggestions I’d like to get them.