Abstract: A speed regulator digital speed controller for rotating machinery is comprised of a single-chip microcontroller operating in conjunction with a multiple counter/time peripheral, and is programmed in a high level language. Pulses are generated by a digital speed sensor at a rate too low to give the required speed resolution; these pulses are counted and a preset number toggles a binary gate signal. Two clock counters both having an input connected to a high reference frequency oscillator are gated alternately and accumulate a count depending on the length of the gated on interval. These speed related counts are read during alternating gated off intervals into the microcontroller where the speed error is calculated in real time to a high degree of accuracy and resolution. The speed of an electric motor and a steam turbine, for instance, are regulated.