Device for reading and writing tape recording medium, accessing method therefor, and recording medium
AssigneeSony Corporation
InventorMasaki Yamada
Life of this patent
Estimating the term…
Abstract
A device for reading and writing data to a tape recording medium divides a magnetic tape into a plurality of partitions. At boundaries between the partitions, optional device areas (ODAs) are formed in which the tape is loaded and unloaded. In each of data areas excluding the ODAs, values of record counts, each indicating the number of recording data, are recorded in a memory in cassette (MIC) in the magnetic tape. When a current position in a predetermined partition is obtained by a host computer, cumulative values of the record count value in each partition are computed. Based on the cumulative values, the current position is computed and output to the host computer.
Claims9
A device for managing reading and writing of data to a magnetic tape, comprising:
- dividing means for dividing a single magnetic tape into a plurality of partitions so that non-recording areas, for use in loading and unloading the magnetic tape to and from the device and in which data is not written, are provided between adjacent partitions;
- first detection means for detecting a number of predetermined data units in each of the plurality of partitions;
- second detection means for detecting cumulative values, starting from a head partition of the plurality of partitions closest to a head end of the magnetic tape, of the number of predetermined data units detected by said first detection means;
- and
- arithmetic operation means for performing an arithmetic operation to determine an access position on the magnetic tape based on the number of predetermined data units from a starting point of a partition to which the access position belongs up to the access position and on a sum of the cumulative values detected by said second detection means up to a partition immediately before the partition of the plurality of partitions to which the access position belongs.
An accessing method for managing a device for reading and writing data to a magnetic tape, said method comprising the steps of:
- dividing a single magnetic tape into a plurality of partitions so that non-recording areas, for use in loading and unloading the magnetic tape to and from the device and in which data is not written, are provided between adjacent partitions;
- detecting a number of predetermined data units in each of the plurality of partitions;
- detecting cumulative values of the detected number of data units starting from a head partition of the plurality of partitions closest to a head end of the magnetic tape;
- and
- performing an arithmetic operation to determine an access position on the magnetic tape based on the number of predetermined data units from a starting point of a partition to which the access position belongs up to the access position and on a sum of the cumulative values detected in the step of detecting cumulative values up to a partition immediately before the partition of the plurality of partitions to which the access position belongs.
A medium having recorded thereon a program for managing reading and writing of data to a magnetic tape, said program comprising:
- a dividing step of dividing a single magnetic tape into a plurality of partitions so that non-recording areas, for use in loading and unloading the magnetic tape to and from a device and in which data is not written, are provided between adjacent partitions;
- a first detection step of detecting a number of predetermined data units in each of the plurality of partitions;
- a second detection step of detecting cumulative values, starting from a head partition of the plurality of partitions closest to a head end of the magnetic tape, of the number of predetermined data units detected in said first detection step;
- and
- an arithmetic operation step of performing an arithmetic operation to determine an access position on the magnetic tape based on the number of predetermined data units from a starting point of a partition to which the access position belongs up to the access position and on a sum of the cumulative values detected in said second detection step up to a partition immediately before the partition of the plurality of partitions to which the access position belongs.
Dependencies are inferred from the claim text.