Abstract: A shock resistant hard disk drive system employs a plurality of magnetic disks for recording data, a plurality of magnetic heads for performing input/output operation on the magnetic disks, with at least one of the magnetic heads being used as a servo head, a head-positioning mechanism for controlling the movement of the magnetic heads, a servo control mechanism or servo loop for opposing shifts in the location of the servo head, detecting device for detecting and measuring certain accelerations applied to the system, and filtering device for filtering the output of said detecting device and for providing the signal to the head-positioning mechanism. The detecting device detects and measures the magnitude of internal or external accelerations or shocks applied to the system, and provides the necessary signals to counter such accelerations.

Abstract: A "floppy" disc digital magnetic storage apparatus or subsystem includes a number of interrelated features permitting greatly increased data storage and good access time, while using relatively inexpensive parts. The features contributing to the greatly increased storage capacity include arrangements for providing one hundred tracks per inch, and for holding tolerances so that the position of the magnetic head in the radial direction is maintained within the required value of plus or minus 1.7 thousandths of an inch.

Abstract: A printed circuit motor is constructed with the printed circuit windings stationary, and therefore constituting the stator of the motor. The stator is mounted at the end of a heavy hollow supporting frame member. The rotor is mounted on the end of a shaft which is journaled within the hollow frame member, and the rotor extends outwardly in close proximity to the stator and around the outer periphery of the stator and back toward the hollow supporting member, with a permanent magnet assembly on one side of the printed circuit stator and the magnetic return path on the other side of it. The permanent magnet assembly and the magnetic return path are rigidly coupled so that no relative motion occurs between them. Electrical connections to the winding turns of the stator are brought out from the periphery of the stator close to its surface through an additional printed circuit board, and along the outer surface of the hollow frame member to pass the inner edge of the permanent magnet rotor.