There is provided a technique for controlling drive of a voice coil motor which
can select, with priority for effective reduction, any one of heat generation and
EMI noise which are presumed to induce a read/write error and for simultaneously
realizing the positioning control of magnetic head with higher accuracy during
the tracking operation and the high speed access with shortening of the seek operation
period. The magnetic disc storage apparatus introducing this technique is provided
with a mode to drive with linear control a coil of the voice coil motor from both
terminals and a mode to drive one terminal of coil with linear control and the
other terminal with pulse width control. Thereby, the coil is driven in the drive
mode of linear control during the tracking operation, while one terminal of coil
is driven with linear control and the other terminal with pulse width control during
the seek operation.