Abstract: A disk drive comprising a first rotatable spindle for rotating removable flexible disks having magnetic surfaces for recording and retrieval of information and a motor for driving the spindle has an increased storage capacity by the addition of a second spindle driven by the motor in a direction opposite to the first spindle. The information storage capacity of the drive is further improved by increasing the track density of the disks while minimizing track seeking error of the magnetic read/write head associated with the disk. A stepper motor and lead screw are coupled to the magnetic read/write heads for radially positioning the heads to selected tracks of the received disks. The lead screw has a V-groove comprised of an alternating ramps and transition zones. As the lead screw rotates, a head carriage assembly having attached the first and second magnetic read/write heads is positioned radially by the transition zones while the ramps function to compensate for angular error of the stepper motor.