A method for controlling a tape motor using a microcontroller for feeding tape in correspondence to printing of an indeterminate length of printing on the tape by a print drum utilizes a sensor for indicating a tape condition which changes in accordance with the engagement of a printing portion of the print drum with the tape. An optical sensor and slotted disk provide signals indicative of the rotation of a motor shaft of the tape motor. At least first and second counters are provided for counting signal pulses from said optical sensor corresponding to the passage of slots during rotation of the motor. From these counts and the indication of printing by the print drum, the micro controller can develop the timing of control signals for controlling the motor in correspondence to the length of printing on the tape.