HAL's Automata 
Universal Cellular AutomataHAL's solutions are expressed in the form of a universal cellular automata 'designed' to solve the specified problem.While in principle HAL should be able to design for virtually any possible system of this type, there are currently some constraints on which models may actually be embedded on the surfaces of HAL's cells. In particular, the automata must currently be uniform, and rotationally symmetrical. We currently use a 5 bitper site system, consisting of 1 bit of RAM (a flipflop) and a four bit, 16state lookup table whose entries correspond to different Boolean logic gates. The use of boolean gates corresponds to the target FPGAbased hardware. Boolean gates are a temporary measure  we are particularly interested in reversible cellular automata, believing these to be of fundamental importance to the future of computation. We have developed several two and threedimensional models which we believe are amongst the most suitable potential target substrates. These are linked to from our Billiard Ball Machine pages.
