Abstract: An external storage system is connected to a host system. A controller unit interposed between disk drives and the host system has a large capacity buffer memory with a battery providing non-volatile storage, a plurality of host interfaces and a plurality of drive interfaces. All the accesses made to the disk drives from the host system are realized via the buffer memory which allows a high-speed access. Read/write processing performed for the buffer memory by the host system is executed asynchronously with read/write processing performed between the buffer memory and the disk drives. The drive interface and the host interface area released during a period in which operation of the disk drive is waited for and recoupled upon data transfer.

Abstract: A housing for an information recording and reproducing apparatus is adapted for increased storage capacity and an increased operating speed by placing a relatively larger number of relatively smaller magnetic disks each having a relatively smaller mass and a relatively smaller recording and reproducing surface in an enclosure and housing the enclosure for a relatively larger magnetic disc in a box-like frame. A shock absorbing device is disposed between the enclosure and the box-like frame to absorb shock. A circuit assembly for controlling the operation of recording and reproducing is disposed outside the enclosure and between the frame and the enclosure.

Abstract: A motor for a disc drive unit is spatially separated from an enclosure housing the magnetic disks and read-write heads. The disks are mounted on a hub that is fixed to a shaft extending through the hub, having bearings at either end of the shaft. One end of the shaft extends outside of the enclosure, the rotor of the motor is fixed to this end of the shaft and is concentric therewith. The rotor has a rotor housing that is cup-shaped, with an opening facing away from the interior of the enclosure. Inwardly of the rotor housing is a stator mounted on a supporting member. The supporting member is detachably mounted to the enclosure for easy access to the stator. Further, a circuit board having control elements for the motor, including a Hall element mounted thereon, is provided on the supporting member for easy access to the circuit board.

Abstract: A method of first erasing the full width of a recording track using an erase core before recording data into a flexible disk and then writing the new data into the erased area using a read/write core, and an apparatus for effecting the same are disclosed. The erasure by the erase core is done in an AC manner. A gap pattern used to form a gap area is written by the read/write core into a portion of the erased area where no valid data has been written.

Abstract: First and second magnetic heads, or magnetic head sliders containing these heads, which are brought into contact with a magnetic disc on its both sides so as to record and reproduce information signals, are respectively supported by first and second swing arms. The first and second swing arms are respectively supported by first and second elastic bodies. The swing arms are respectively provided with first and second adjusting screws for adjusting the movable range of the swing arms. The first adjusting screw operates to adjust the pressure of a first spring supported by the first arm and the position of the first magnetic head. The second adjusting screw operates to locate the associated second magnetic head to a position which is adjusted to the thus-adjusted position of the first magnetic head.

Abstract: In a disk unit having a rotating mechanism to rotate the disk by pinching the disk at both sides, and a loading mechanism to bring a read-write head into contact with the disk, a method for driving the disk includes the steps in which, at the time of recording and reproduction, the rotating mechanism and the loading mechanism are actuated simultaneously, and when the recording and reproduction are completed, the rotating mechanism is stopped simultaneously with release of the loading mechanism, or after the lapse of a predetermined time from the release.