Abstract: A motor control system for use in maintaining substantially constant linear speed of a web moving between a supply and a takeup reel such as in a reel driven magnetic tape transport. The rotational periods of the reels are measured to provide representative signals which are summed and compared with a reference to yield an error signal for control of takeup reel motor driving voltage such that the error voltage tends to become zero, resulting in substantially constant linear web speed. In alternative embodiment, the period representative signals are each non-linearly processed prior to summing to enhance the accuracy of web speed control. In further embodiment, the rotational frequencies of the web reels are measured to provide representative signals which are each non-linearly processed and then summed and from which summed signal is derived a resulting error voltage for web speed control.

Abstract: For use with a magnetic data recording having one or more data tracks and a clock track, a decoding system for providing strobe pulses derived from the clock track in intended phase relationship with the decoded data. A measure of the clock pulse period is continuously derived from the clock track and processed in association with information derived from the data track to produce the intended strobe pulses.