Abstract: A disk drive in a multi-disk storage system has a spindle synchronizer and a spindle controller that are microprocessor-based. The spindle synchronizer has a counter used to track the phase of a master phase reference signal that is distributed to all the disk drives in the storage system. The counter may also optionally be used to generate the master reference signal. The spindle synchronizer also has programmable registers and a comparator that are used to generate a spindle reference signal having a programmable phase offset relative to the master reference signal, and a register used to sample the phase of the master reference once per revolution of its associated spindle. The spindle controller contains a counter used to measure the actual rotational period of the associated spindle. The spindle phase error is used in a phase correction algorithm that controls a reference voltage supplied to a motor spin controller.