Abstract: An access control method controls access to a storage medium in a storage apparatus, by obtaining key data valid information which indicates whether or not a key data is valid, and enciphering data to be recorded in the storage medium using the key data only when the key data valid information is turned ON.

Abstract: A storage apparatus is capable of using a storage medium having at least a first region for storing therein data and a second region for storing therein both use permission discrimination information indicative of permission of a predetermined access operation and use limit information with respect to the storage medium.

Abstract: In a disk drive, a read-ahead operation is prevented from being aborted due to an interrupt such as an error, to prevent the operation of a host device from stopping and to enhance reliability. The disk drive is connected to a host computer, the host device, via an interface, and performs read ahead after reading data in accordance with a data read command received from the host computer. When a read-ahead abort prevention function is provided at the host computer side, if the read ahead is interrupted by detecting an error at the disk drive side during the read ahead, the host device, after receiving an error report, causes the disk drive to resume the read ahead from the address at which the read ahead was interrupted. On the other hand, when the read-ahead abort prevention function is provided at the disk drive side, the disk drive, upon detecting an error, retries the read ahead from the address at which the error occurred.

Abstract: There is disclosed an information reproducing apparatus and an information recording apparatus in which information transfer is possible by an information amount unit different from a sector unit, so that a burden on a host apparatus is lightened, waste of transfer time is avoided, and information protection level is raised. In a magnetooptic disk drive 10 which serves as both the information reproducing apparatus and the information recording apparatus, non-sector unit information is designated as reproducing information, information for the integer number of sectors including the non-sector unit information is reproduced from a magnetooptic disk 20, and only the non-sector unit information is outputted to a host computer 30.

Abstract: A storage device has access protection functions, enabling the resolution of problems occurring when, despite the fact that the actual access restriction state has changed, this change is not correctly transmitted to the host device (information processing device). The access control method of a storage device performs driving at least for reading of storage media by means of a host device control system, in which said control system is notified of the replacement of said storage media when the access permission state of said storage media has changed, without the physical removal of said storage media from said storage device.

Abstract: An accessible count information which is the number of accessible times for recording medium is recorded on an additional recording dedicated area in the recording medium. Each time the recording medium is accessed, the accessible count information is subtracted and the value of remaining accessible count information is recorded in a non-recorded portion of the dedicated area. In this case, the access to the recording medium is controlled based on the minimum value of the accessible count information recorded in the dedicated area.

Abstract: An accessible count information which is the number of accessible times for recording medium is recorded on an additional recording dedicated area in the recording medium. Each time the recording medium is accessed, the accessible count information is subtracted and the value of remaining accessible count information is recorded in a non-recorded portion of the dedicated area. In this case, the access to the recording medium is controlled based on the minimum value of the accessible count information recorded in the dedicated area.

Abstract: An access control method controls access to a storage medium in a storage apparatus, by obtaining key data valid information which indicates whether or not a key data is valid, and enciphering data to be recorded in the storage medium using the key data only when the key data valid information is turned ON.

Abstract: In a disk drive, a read-ahead operation is prevented from being aborted due to an interrupt such as an error, to prevent the operation of a host device from stopping and to enhance reliability. The disk drive is connected to a host computer, the host device, via an interface, and performs read ahead after reading data in accordance with a data read command received from the host computer. When a read-ahead abort prevention function is provided at the host computer side, if the read ahead is interrupted by detecting an error at the disk drive side during the read ahead, the host device, after receiving an error report, causes the disk drive to resume the read ahead from the address at which the read ahead was interrupted. On the other hand, when the read-ahead abort prevention function is provided at the disk drive side, the disk drive, upon detecting an error, retries the read ahead from the address at which the error occurred.

Abstract: A storage device has access protection functions, enabling the resolution of problems occurring when, despite the fact that the actual access restriction state has changed, this change is not correctly transmitted to the host device (information processing device). The access control method of a storage device performs driving at least for reading of storage media by means of a host device control system, in which said control system is notified of the replacement of said storage media when the access permission state of said storage media has changed, without the physical removal of said storage media from said storage device.

Abstract: There is disclosed an information reproducing apparatus and an information recording apparatus in which information transfer is possible by an information amount unit different from a sector unit, so that a burden on a host apparatus is lightened, waste of transfer time is avoided, and information protection level is raised. In a magnetooptic disk drive 10 which serves as both the information reproducing apparatus and the information recording apparatus, non-sector unit information is designated as reproducing information, information for the integer number of sectors including the non-sector unit information is reproduced from a magnetooptic disk 20, and only the non-sector unit information is outputted to a host computer 30.

Abstract: A storage apparatus is capable of using a storage medium having at least a first region for storing therein data and a second region for storing therein both use permission discrimination information indicative of permission of a predetermined access operation and use limit information with respect to the storage medium.