Structure in asynchronous cellular automata

Abstract The properties of synchronous cellular automata are compared with two types of cellular automata which iterate asynchronously either at random or with clocks of slightly different periods. It is shown that some of the apparent self-organization of cellular automata is an artifact of the synchronization of the clocks. The structure which does exist in asynchronous cellular automata is compared with that found in the synchronous case and some apparently new forms of self-organization which appear are studied.