The Hodgepodge Machine Here is a really strange cellular automaton from the pages of Scientific American that seems to simulate the waves that occur during some chemical reactions. By controlling the automaton parameters you can determine the type of patterns produced, the rate of pattern evolution and the intensity of any reaction waves produced after evolution. To me it is another toy for making endless 'hippie' designs. The Hodgepodge Machine, as it was called by its creators Martin Gerhardt and Heike Schuster, simulates the reactions that take place in exitable chemical mediums, two or more compounds that can dissociate and recombine in the presence of a catalyst. If the chemical states of the reactants have different colors, wavelike structures can be seen that propagate along simple or intricate frontiers in endless pursuit of an elusive equilibrium, as stated in the August 1988 Scientific American. Hodgepodge uses a 80 by 96 grid of cells with each cell having a large number of possible states, up to 255. The states are reduced to a four color image in graphics mode 7. The automaton starts off in a random state using four variables to control production of new generations. These are: NS Number of cell states K1 Constant 1 (infect) K2 Constant 2 (ill) G Rate of infection. A cell is termed healthy if state 0 and ill if in the maximum state, NS. Any state between healthy and ill are varying degrees of infection. Three rules are applied to each cell depending on if it is healthy, infected or ill. The future state of a cell is affected by its eight surrounding cells. All future states are computed before going to the next generation. A = number of surr. infected cells B = number of surr. ill cells S = sum of surr. cell states If healthy then newstate=[A/K1]+[B/K2] If infected then newstate=[S/A]+G If ill then newstate=0 The  brackets mean round down, 2.75 comes out 2. This happens anyways in machine code. Basically the K1 and K2 variables control the behaviour of healthy cells in state 0 and if surrounded by healthy cells stays healthy. G controls the infected cells and the infection rate is accelerated by surrounding sick cells. Finally any cell that makes in to the final state of ill becomes healthy in the next generation. Main Menu... N Change number of cell states 1 Change constant one 2 Change constant two G Change rate of infection S Initialize with random start C Continue with current states These selections are shown in a text window along with the current values and the cycle number. During the generation process press ESC to get back to menu.