A self powered lock is powered by a manually driven generator. The data input to the lock is entered by rotating the dial and stopping and waiting a predetermined amount of time when a desired number is displayed on the lock display. The drive of the power generator, a stepper motor, is through a unidirectional clutch, such that the generator is only driven when the dial is rotated in a selected direction and remains stationary when the dial is rotated in the opposite direction. The data input, including entry of the combination, to the lock is provided by a stepper motor which generates a train of electrical pulses. The electrical pulses are used by the electronic controls of the lock to control the electronic controls including entering the combination. The data input pulses are generated by a stepper motor driven to act as a generator. The data input generator is similarly driven through a unidirectional clutch and is driven only when the dial is being rotated in a direction opposite the direction in which the power generator is driven. Accordingly, only the power generator or the data input generator is driven at any one time, depending upon the direction of rotation of the dial. A third unidirectional clutch is used to grasp the shaft of the data input stepper motor, preventing the reverse rotation of the rotor when the dial of the lock is rotated to generate operating power.