摘要:
A method for registering a defect map within a hard disk drive is disclosed. A hard disk drive includes a recording disk, a head assembly, and a controller. Multiple sectors are formed on the recording disk, and the head assembly includes a head for reading/writing data from/to the recording disk. The controller, which controls the head assembly to read/write data from/to the recording disk, includes a defect sector positional information holding device and a sector identification device. The defect sector positional information holding device holds positional information of a defect sector disabled to read/write data therefrom/thereto the recording disk. The positional information includes the number of the defect sectors continued in a circumferential direction and in a radial direction of the recording disk. The sector identification device refers to the positional information of the defect sector so as to identify a target sector from/in which data is to be read/written when a read/write command is received from a host computer.
摘要:
A disk drive has an error recovery procedure with a plurality of ERP steps. An unused capacity of an alternate area on a disk for reassigning data is determined. While executing the error recovery procedure, an execution condition for reassigning data is changed based unused capacity of the alternate area. Data is reassigned to the alternate area in response to the execution condition. This prevents the early loss of the alternate area.
摘要:
Cobalt-containing iron oxide magnetic particles having a high coercive force and a small surface electrical resistance which are useful as a recording element for a magnetic recording medium, and a method for the preparation of the same comprising reducing acicular .gamma.-Fe.sub.2 O.sub.3 particles in a reducing gas or liquid until the iron oxide reaches an intermediate oxidation state between .gamma.-Fe.sub.2 O.sub.3 and Fe.sub.3 O.sub.4, dispersing the resulting iron oxide particles into an aqueous solution containing a cobalt salt and optionally a ferrous salt and an alkali of one equivalent or more to the metal salt(s), and heating the mixture at a temperature of higher than room temperature up to a boiling point of the mixture under an atmospheric condition such that the divalent iron is substantially not oxidized. The cobalt is thereby predominantly incorporated into the most outer layer of the acicular iron oxide particles.
摘要翻译:可用作磁记录介质的记录元件的具有高矫顽力和小表面电阻的含钴氧化铁磁性颗粒及其制备方法包括还原针状γ-Fe2O3颗粒的还原性 气体或液体,直到氧化铁在γ-Fe 2 O 3与Fe 3 O 4之间达到中间氧化态,将得到的氧化铁颗粒分散到含有钴盐和任选的亚铁盐和一当量或更多的碱金属盐的水溶液中 并在大气条件下在高于室温的温度下将该混合物加热到混合物的沸点,使得二价铁基本上不被氧化。 因此,钴主要并入针状氧化铁颗粒的最外层。
摘要:
A hard disk drive (HDD) according to an embodiment of the present invention uses three primary defect map (PDM) formats: a single-sector entry format; a multi-sector entry format; and a two-dimensional sector entry format. Methods of registering defective sectors in each such format are illustrated. Defects can be appropriately registered in a limited RAM capacity by selecting an appropriate format according to states of the defects on a magnetic disk.
摘要:
Embodiments in accordance with the present invention increase the reliability of a data storage device, and to reduce the circuit size. According to one embodiment of the present invention, a hard disk drive (HDD) executes not only error correction processing of data to be written to a magnetic disk, but also error correction processing of data stored in the DRAM. In the HDD according to this embodiment, one SRAM is shared by both kinds of error correction processing. As a result of executing the error correction processing of the data stored in the DRAM, the reliability of the HDD is improved. In addition, by using the same SRAM for the two kinds of error correction processing that differ from each other, it is possible to suppress the increase in circuit size.
摘要:
Embodiments in accordance with the present invention prevent abnormal action of the actuator of a disk drive. According to an embodiment of the invention, in the process of startup (power on reset (POR)), a hard disk drive (HDD) checks whether an arm electronics (AE) port table stored in an EEPROM agrees with the ports of an AE to which head device portions are actually connected before it starts the rotation of a magnetic disk to move the actuator onto a user data area. Thus, even if an HDA and a reused circuit board do not agree at the manufacture of the HDD, the abnormal action of the actuator can be prevented.
摘要:
An Error Recover Procedure (ERP) is disclosed which, during execution of the ERP, while self-diagnosing the cause of error, dynamically changes the error recovery steps of the ERP. An appropriate ERP is selected and executed according to the detected error status.
摘要:
A magnetic recording medium which comprises a first magnetic layer on a base and a second magnetic layer thereon, the first magnetic layer containing magnetic particles having an average particle length (long axis diameter) of 0.4 to 0.7 .mu., the second magnetic layer containing magnetic particles having an average particle length (long axis diameter) of 0.25 to 0.35 .mu., the coercive force of which being 370 to 460 oersteds, and the ratio of coercive force of the upper or second layer to that of the lower or first magnetic layer being 1.05/l to 1.5/l. The magnetic recording medium has excellent sensitivity and frequency characteristics at entire frequency bands with less noise.
摘要:
Embodiments of the invention provide a disk drive capable of preventing the deterioration of performance. In one embodiment, a disk drive includes a disk medium; a head capable of performing a read/write operation for accessing the disk medium to read information from and to write information to the disk medium; a head controller for controlling the position of the head so that the head describes a substantially spiral trajectory relative to the disk medium; and a controller capable of controlling the head controller, of performing a read/write operation for reading or writing information with reference to an identifier table associating sector identifiers identifying sectors on a specified track with logical block addresses, and of creating an identifier table for a track to be accessed next during the read/write operation.
摘要:
A HDD defragments itself while idle or in self-test when a defragmentation count exceeds a threshold. Also, the HDD combines G-list entries when a discontinuity count and a G-list entry density are both over a threshold.