EDIT: Forever A Troll from the Minecraft Forums posted this usefull list: pTransistor - Tristate buffer(functioning like an AND gate) ipTransistor - Inverted tristate buffer(functioning like an IMPLIES gate) pPulser - Clock generator. cTransistor - 2-to-1 multiplexer. pcoPulser - Clock generator(with an inverted output as well). 4ppPulser - Quadruple clock generator. pBMemory - A very crappy punched card reader. PBM Array - A VERY EPIC punched card reader!