Global Control in Polymorphic Cellular Automata

The notion of locality is fundamental for cellular automata. However, introducing a kind of global information to some or even all the cells can significantly increase the effectiveness of computation. We used a two-value discrete global signal which allowed the cells to change the local transition function during computation. On the basis of the signal we could generate new patters in a simple 1D cellular automaton and accelerate selfreplication of Byl's loop in a 2D cellular automaton (the speedup obtained is 48%). In the case of 1D automaton we demonstrated that the overhead introduced with the global control can be relatively small if the implementation is performed using polymorphic gates controlled by the level of power supply voltage.