Magnetic disk unit and method for controlling the same

Abstract

In an idle state, servo information from all sectors is not used, but the servo information from every other sector or from every three or more sectors is used so that head positioning can be performed with only a minimum amount of servo information. The power to the electric circuitry of a write or read system and a servo system, which is not needed in the idle state, is interrupted, from the arrival of the selected servo information to the arrival of the next selected servo information, by a power control signal generated in accordance with the timing of the sectors. The power consumption can be reduced by the amount corresponding to turning off the circuitry not needed, plus the amount needed for computing for position control.