Abstract: A magnetic disk drive has a housing for a 3.5 inch form factor and disk media of a diameter for a 2.5 inch form factor. The smaller disk media rotate at a high speed while consuming low electric lower and generating less heat while providing for quick access speeds. Usually, when the magnetic disk media are rotated at a higher speed, the electric power consumption and heat generation are increased because of the load increase. This problem is avoided with the use of cooling fins placed about the periphery of the disk media. Further, the smaller size disk media enable a decrease in torque loss during on-load rotation with the media, and a decrease of electric current to the spindle motor during rotation.

Abstract: A magnetic disk drive that shape coefficient is 3.5 inches are provided, which is designed as rotating magnetic media in a high speed in order to consume a low electric power, to generate a less heat, and to access more quickly.

Abstract: A magnetic disk drive that shape coefficient is 3.5 inches are provided, which is designed as rotating magnetic media in a high speed in order to consume a low electric power, to generate a less heat, and to access more quickly.

Abstract: A magnetic disk drive that shape coefficient is 3.5 inches are provided, which is designed as rotating magnetic media in a high speed in order to consume a low electric power, to generate a less heat, and to access more quickly.

Abstract: A magnetic disc apparatus has a large recording density of 120 megabits per square inch or more, and defines a relationship among a pole thickness (Pt) of thin-film magnetic heads disposed in the magnetic disc apparatus, and a saturation flux density (Bs) of cores of the heads and a recording wavelength (.lambda.) for the thin film magnetic discs have a coercivity of 1800 Oe or more, wherein a levitation space between the head and the disc is 0.15 .mu.m or less.

Abstract: The write data is entered from the upper unit into a nonvolatile cache provided in a controller inside of each disk unit through a channel adaptor, a cache shared by each disk, and a disk adaptor. The data from the cache is compressed by the data compressing and restoring device and is written in the disk. At a time, the management information for compressed data is written in the cache and the disk as well. In case of breaking the management information of the cache when a failure takes place in the cache memory, the management information is written for each disk. Hence, the breakage does not have an adverse effect on the other disks. If the management information of the cache is broken, the management information given into the disk may be replaced with the broken information.

Abstract: A semiconductor storage device transfers data with an information processing device and includes a non-volatile semiconductor memory in which data is electrically re-writable, a volatile semiconductor memory connected to the non-volatile memory and temporarily storing data of the non-volatile semiconductor memory, and a CPU connected to the volatile semiconductor memory and the non-volatile semiconductor memory. The CPU controls the transfer of data among the non-volatile memory, the volatile memory and the CPU. The CPU also transfers data with the information processing device in accordance with a fixed-length form for data. When an access from the CPU to the volatile semiconductor makes a miss hit (i.e., misses), the CPU accesses the non-volatile semiconductor memory. When a failure is generated in the non-volatile semiconductor memory or when a predicted service life of the non-volatile semiconductor memory is elapsed, the non-volatile semiconductor memory can be substituted by an alternate memory.

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 semiconductor storage device is connected to at least one magnetic storage device. The input and output of data is made between the semiconductor storage device and an information processing device.

Abstract: A magnetic disk apparatus includes a base coupled to a supporting frame by means of a damping member so that the vibration caused by the operation of the internal actuator subsides. The damping member may include an adhesive resilient material disposed between the base and the supporting frame.

Abstract: The write data is entered from the upper unit into a nonvolatile cache provided in a controller inside of each disk unit through a channel adaptor, a cache shared by each disk, and a disk adaptor. The data from the cache is compressed by the data compressing and restoring device and is written in the disk. At a time, the management information for compressed data is written in the cache and the disk as well. In case of breaking the management information of the cache when a failure takes place in the cache memory, the management information is written for each disk. Hence, the breakage does not have an adverse effect on the other disks. If the management information of the cache is broken, the management information given into the disk may be replaced with the broken information.

Abstract: A magnetic head for reading from and/or writing to a magnetic information storage medium has a substrate on which a plurality of thin films are formed in sequence. The films provide a magnetic circuit having a magnetic gap, a bottom pole piece and a top pole piece overlying said bottom pole piece. The top pole piece is formed as a tip portion adjoining the magnetic gap and a rear portion which makes magnetic contact with the tip portion. The rear portion is formed in the sequence after the tip portion. To ensure accurate thickness and width of the tip portion, a non-magnetic protective film is formed on the tip portion after the tip portion is formed and before the rear portion is formed.

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 magnetic head disk apparatus has a housing with one thicknesswise end providing the front side and the other thicknesswise end providing the rear side of the apparatus. The apparatus further has a plurality of head disk assemblies each including at least one combination of a magnetic head and a magnetic disk. The head disk assemblies are arranged in a plurality of rows not only in heightwise and breadthwise directions but also in the thicknesswise direction of the housing. With this arrangement, it is possible to accommodate a multiplicity of head disk assemblies with a high space factor in the housing.

Abstract: An electronic apparatus, such as a disk apparatus, has a plurality of electronic units such as magnetic head-disk units and at least one power source unit for supplying power to the electronic units. The arrangement of the electronic apparatus is such that, on a frame of the apparatus, the plurality of electronic units are vertically arranged in such a manner as to form a first arrangement system, while the at least one power source unit is arranged in such a manner as to form a second arrangement system above the first arrangement system. The apparatus has an air flow passage for causing cooling air to flow from a lower portion of the electronic apparatus to the inside thereof, pass through the first arrangement system, thereby pass through the second arrangement system, and then be discharged to the outside of the apparatus.

Abstract: Because of increase in data recording density on a magnetic disk in recent years, a minute defect which posed no problem in the past exerts adverse influence upon the recording and reproducing characteristics. An object of the present invention is to provide a method and an apparatus for detecting minute defects on a magnetic disk. In order to achieve this object, the present invention was made on the basis of the recognition that a large defect on the magnetic disk largely decreases the amplitude of the reproduced signal and shifts its phase, whereas a small defect does not decrease the amplitude of the reproduced signal so largely but causes a phase shift. Therefore, defects on the magnetic disk are detected by monitoring the amplitude decrease and phase shift of the reproduced signal.

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: 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.

Abstract: A magnetic disc unit capable of improving the throughput by minimizing the seek time for the magnetic head. The magnetic disc unit is operative to respond to a cylinder address instructed by the host unit to move the magnetic head to the corresponding cylinder position on the magnetic disc comprises a cylinder address/position assignment selecting circuit for changing the address instructed by the host unit into a new address so as to desirably change cylinder address/position assignments. A head location controlling circuit is responsive to the new address to move the magnetic head to a cylinder position corresponding to the new address. In one mode, the cylinder address/position assignment selecting circuit performs renewal of cylinder addresses such that the magnetic head passes along the magnetic disc through all of the cylinder positions designated by cylinder addresses by making a return trip between inner and outer circumferences of the magnetic disc.