Power saving system for rotating disk data storage apparatus

摘要

A flexible magnetic disk drive is disclosed which has a stepper motor coupled to a data transducer via a steel belt motion translating mechanism for moving the transducer from track to track on the rotating disk in response to stepping pulses and a stepping direction signal from an external host system. In order to save power, the stepper motor is held deenergized while the disk drive motor is out of rotation, with the consequent possibility that the transducer may be displaced from the required track position on the disk while the stepper motor is held deenergized. Therefore, in order to always memorize the latest of the successive destination tracks commanded by the host system, a forward/backward counter is provided which counts the external stepping pulses in either direction depending upon the binary state of the external stepping direction signal. After the disk drive motor is set into rotation, stepping pulses and an stepping direction signal are generated internally for causing the stepper motor to automatically reposition the transducer on the memorized latest destination track.