A boiler fuel distribution control system in which a boiler fuel demand signal is employed to regulate the rate of grinding of the fuel within predetermined limits of air supply so the grinding of the fuel material is accomplished at a desired mill grinding speed and within a fluid bed differential pressure across the grinding mill to maintain a supply of fuel adequate to keep up the desired boiler operation. It is also a system in which stand alone isolated control computer accessories can be temporarily manually adjusted to the control system until a replacement is available.