A drum-in-hat disc brake assembly has a disc service brake and a drum-in-hat parking and emergency brake, and includes a backing plate, a pair of parking and emergency brake shoes secured to the backing plate, and a parking and emergency brake actuator. The positioner is moved in the radial direction of the disk by the motor through gear train. The selected differential data store is copied into temporary storage media, where the copying is not delayed after receiving the first request to await receipt of more requests.