Disc drive unit and method and system for controlling the same

A disc drive control method in which a command for disc rotation is sent to the disc drive mechanism upon receipt of a 'drive-ON' signal, a timing operation is started in response to receipt of a 'drive-OFF' signal, and a command for stoppage of the disc rotation is sent to the disc drive mechanism if there is no further 'drive-ON' signal received within a predetermined time interval. A disc drive control system comprises devices for effecting the steps of the disc drive control method. A disc drive unit employable in the disc drive control method and system comprises a disc drive mechanism for producing rotational movement of a disc and a disc drive control device for controlling rotation of the disc by means of the disc drive mechanism. The disc drive control method and/or system may also be applied to an information processing system which comprises at least a processor and a flexible disc drive unit.