To solve the problems that the countermeasure for vibration and noise is required every time when the change of hardware is effected such as the change of an electrical circuit including a motor and others or of a structural part, and that the change of an upper limit value of the rotation speed of the disk is not allowed at the user's side even though the noise at the time of high speed rotation is unpleasant to the user.
The arrangement is made so that the upper limit value of the rotation speed of the disk is changeable by the software in accordance with the user's own judgement. Thus, the rotation apeed is set to the speed such as not to make the user feel uncomfortable, and the additional countermeasure for the vibration or noise is no more required even though the design change of the hardware is effected in the disk device.
YAMAHANA MASATSUGU
KANBE SHINICHI
