A disk drive for writing and reading data to and from a disk contained in a cartridge which is inserted through an opening into the disk drive comprises a motor ring rotatably mounted in the disk drive and a spindle motor for rotating the disk. The spindle motor is mounted in the motor ring such that rotation of the motor ring moves the spindle motor into and out of engagement with the hub of the disk cartridge. A position transducer provides an output signal indicative of the rotational position of the motor ring. A load/eject motor controls the rotation of the motor ring in response to the output signal from the position transducer.