Motor turns a mechanical
screw which "steps" a drive's actuator-arm,
one-track-at-a-time to the specified read/write
position. You can hear a soft "buzz" or "beep" each time
the motor turns the screw, on-off, on-off... moving the
actuator-arm's read/write head track to track. A motor
that has known detent positions where the rotor will
stop with the proper control in some cases. The
digitally controlled motor moves the head positioner
from track to track in small, step-like motions.
Stepper Motor