International Business Machines Corporation

U.S. Philips Corporation

Judson A McDowell

Glen Alan Jaquette

John Edward Kulakowski

Rodney Jerome Means

Leonard George Jesionowski

Arturo Avila Mojica

David E Call

Lawrence D Tipton

John E Bish

Brian Gerard Goodman

Karl Arnold Belser

Kurt A Rubin

Johannus Leopoldus Bakx

Ernest William Devore

David A Yeary

Paulus G Weijenbergh

Alfred W Blanco

Provided is a method, system, and program for storing data in a storage medium. A layout of a storage medium including a first and second user data sections is provided, wherein the first user data section comprises a faster access storage space than the second user data section. A determination is made of a first set of data to be accessed with less delay than a second set of data. The first set of data is written to the first user data section and the second set of data is written to the second user data section.

Method, system, program, and storage cartridge for storing data in a storage medium

A tamper-resistant Hard-WORM data storage system and a magneto-optical storage disk therefor is disclosed. The disk has a plurality of sectors thereon containing one or more uniquely formatted fields to provide an indication that the disk is a Write-Once Read Many (WORM) disk. A motor is provided in the storage system for rotating the disk at an operational rotational speed and a laser read/write (R/W) head unit is provided for reading and writing information in the sectors. A read/write (R/W) control unit within the storage system controls read and write operations on the disk in response to commands from an external data processing device, such as a computer. The R/W control unit is adapted to decode the one or more uniquely formatted fields in order to read and correctly interpret information contained therein. In an additional aspect of the disclosure, the R/W control unit disables erase operations in sectors containing uniquely formatted fields but allows such operations in sectors that do not contain such fields in order to permit calibration testing and the maintenance of media defect lists, first available sector lists and the like.

Low cost tamper-resistant method for write-once read many (WORM) storage

The present invention provides efficient management of calibration and spare sectors on a banded optical write-once, read-many (WORM) disk. A portion of each band on the disk includes a user data area and a reserved area. Sectors in the reserved area are usable either as spare sectors, replacing defective sectors in the user area, or as calibration sectors, for use when the laser write-power level is calibrated. Sectors preferably are used for sparing from one end of the reserved area while sectors are used for calibration from the opposite end. A common overflow reserved area can also be provided for use if all of the sectors in one or more primary reserved areas associated with any of the bands have been exhausted.

Spare and calibration sector management for optical WORM media

The present invention provides a method and an apparatus to accurately and consistently distinguish blank sectors from written sectors on optical media despite drive and media variations. A readback envelope threshold is established each time optical media is mounted into an optical drive. In one embodiment, the gain of readback amplifiers are set to a first level, the optical head seeks to and reads a sector or set of sectors on the optical disk known to have information recorded thereon and a first readback envelope generated. The gain of the readback preamplifier is then set to a second level, the optical head seeks to and reads another sector or set of sectors known to have information recorded thereon and a second readback envelope generated. The readback threshold is calculated from the amplitudes of the first and second envelopes. Once the threshold has been calculated for a disk, the drive can scan for a blank sector by comparing the amplitude of the sector's readback envelope with the threshold: if the amplitude is less than the threshold, and no other written format feature is readily indicated the sector can be classified as being blank and it is safe to write to the sector.

Calibration of readback threshold in an optical storage device to

The present invention provides a method and an apparatus to accurately and consistently distinguish blank sectors from written sectors on optical media despite drive and media variations. A readback envelope threshold is established each time optical media is mounted into an optical drive. In one embodiment, the gain of readback amplifiers are set to a first level, the optical head seeks to and reads a sector or set of sectors on the optical disk known to have information recorded thereon and a first readback envelope generated. The gain off the readback preamplifier is then set to a second level, the optical head seeks to and reads another sector or set of sectors known to have information recorded thereon and a second readback envelope generated. The readback threshold is calculated from the amplitudes of the first and second envelopes. Once the threshold has been calculated for a disk, the drive can scan for a blank sector by comparing the amplitude of the sector's readback envelope with the threshold: if the amplitude is less than the threshold and no other written format feature is readily indicated, the sector can be classified as being blank and it is safe to write to the sector.

Calibration of readback threshold in an optical storage device

A record carrier having essentially circular tracks concentrically located around a point of rotation. The record carrier is divided into circular zones each having m tracks, where m is an integer. Each track within a zone is subdivided into n sectors, where n is an integer which is constant per zone and which increases as the zone is more remote from the point of rotation. Each sector including a header portion and a data portion. The header portions in the radial direction in each zone are in line. In each zone the condition of m*n=j*k is satisfied, where is j an integer greater than or equal to 2 and is constant for each zone, and k is an integer.

Zoned record carrier

Data-storing disks, preferably each disk having a single spiral track, have addressable tracks that are independent of the length of disk or spiral track revolutions. Each revolution may contain a non-integral number of addressable tracks and sectors. An optical disk is used to describe the invention. The circumferential location of the tracks and sectors precess circumferentially. A plurality of radially disposed revolution bands each contain a fixed number of the revolutions an increasing number of the addressable tracks in the radially outer more ones of the bands. It is preferred that the number of bands be 2.sup.n, where n is an integer. Each band is divided into a plurality of revolution groups, each group having a fixed number of revolutions. Each group in a band has a like number of the addressable tracks. A so-called anchor sector has one end anchored to a reference circumferential position on the disk. Each revolution group begins with an anchor sector, all other sectors in the group are positioned circumferentially with respect to the anchor sector. Addressable track seeking, alternate embodiments and fabrication of a disk are described.

Fortmat for data-storing disk media wherein addressable track angular

Error control procedures are described for an optical disk recorder. High and low criteria for each of a plurality of machine operations or functions of an optical disk recorder are described. Such functions include erasing a sector, writing data, and reading data. Each function has two sub parts, reading a sector ID and performing the function in a data field. The high and low criteria for reading the sector ID and for performing the function in the data field, are different. The high and low criteria for a ROM portion of the optical disk are different from that provided for magnetooptic portion.

Optical disk device using high and low data-sensing criteria plus device

With high density reel-to-reel tape drives, slight perturbations in the tape path can cause instantaneous speed variations in the tape which can alter the recording density of data on the tape over a very short interval. This condition can be detected by measuring changes in recording intervals on a plurality of data tracks. Whenever all of the tracks indicate an unacceptable change in the recording interval an unacceptable speed variation has been encountered.

Detection of instantaneous speed variations in a tape drive

Each data record portion on a record member includes preamble signals for synchronizing recording apparatus with respect to data signals recorded in juxtaposition to the preamble signals. A plurality of beginning of data indicators are interleaved in the synchronizing signals for providing a plurality of independent but coacting beginning of data location pointers. Enhanced apparatus includes means responsive to any one of the location pointers to ensure a reliable start of data indication.

Growing community of inventors

Tucson, AZ, United States of America

Judson A McDowell