Hostetter's on Switch and the Domino Network

One domino is designated as the on switch when it is knocked over. The programm computes whether a given number is a prime or not. One inputs that number by placing a stretch of exactly that many dominoes at a specified position for tripping the on switch. Elsewhere in the network, a particular domino will deliver the output of the computation. It will fall only if a devisor is found indicating that the input was not prime. Flurries of motion begin to sweep back and forth across the network. All 600 forty one of the inport dominoes soon fall as the computation reads its input and snaps back up.