Abstract: An axial gap motor for use in a disk drive includes a rotatable magnet rotor and fixed first and second windings closely spaced from the rotor. The rotor and windings are disposed coaxially about a rotatable spindle to which the rotor is mounted. Current supplied to one winding actuates the rotor to rotate in a run mode. Current supplied to the other winding positions the rotor for maximum torque for starting the motor, and enables the sensing of the speed of the rotating rotor.

Abstract: A portable computer having an associated disk drive includes a voltage multiplier coupled between a microprocessor and a head positioning actuator that operates in two modes. In a moderate performance mode, the dual mode actuator operates with the power supplied by a storage battery or by a commercial power source with the voltage multiplier turned off. In a high performance mode, the voltage multiplier under control of the microprocessor boosts the voltage supplied to the actuator so that more power is made available for fast head positioning and job execution with an improvement in computer performance.