Abstract: A positioning system is provided in which command and feedback signals are processed to develop an analog error signal for application to a servo drive to position a controlled element. The command signals are in the form of pulses each of which corresponds to a certain incremental distance of movement. The feedback signals are developed from phase shifts of a low frequency resolver signal, such phase shifts being proportional to movement of the element. Such feedback signals are applied to a resolver digitizer circuit which develops a train of resolver pulses in response to the phase shift represented by each feedback signal. Each such resolver pulse corresponds to the same incremental distance of movement as a command pulse and both the resolver pulses and the command pulses are applied to a comparator and error signal circuit in which any cumulative error in either direction is stored as a digital number and is converted to an analog error signal of the proper polarity.