International Business Machines Corporation

David C Graves

James Lee Lentz

Pamela Ruth Nylander-Hill

Alex Chliwnyj

Scott Milton Fry

Paul Y Hu

Richard C Schneider

Will A Wright

Douglas W Johnson

Volker W Zimmermann

John James Gniewek

Dale A Christiansen

Guillermo S Robles

Wayne T Comeaux

James Alfred Jackmond

Loyal Keith Whitted

Donald Charles Acosta

Kenneth Dean Cummings

Habib M Torab

Donald Ernest Lockett

An automatic cartridge feeder includes a magazine slot that receives a cartridge magazine and includes a priority slot that directly receives single cartridges. The automatic cartridge feeder can receive a cartridge through the priority slot regardless of the condition of the cartridge magazine. In an automatic mode, cartridges are taken sequentially from the magazine and are processed. Any cartridge placed in the priority slot by an operator will be processed immediately after any in-progress cartridge processing. In an accumulate mode, cartridges are received through the priority slot for processing and are returned in sequence to an empty cartridge magazine.

Automatic cartridge feeder with priority slot

A cartridge magazine with interfaces to automatic cartridge feeder devices. On one side, the magazine has an open interface that provides unencumbered access by a robotic picker that accesses cartridges for a library. The magazine is accessible on another side by a transport mechanism of an automatic cartridge feeder (ACF). The transport carries a cartridge from the magazine to a drive unit where the data stored on the cartridge is read or new data is written. The interface to the ACF includes a handle member for placing the magazine into the feeder. The magazine is mounted by loading it into the feeder and pushing the handle inward allowing a plunger on the ACF to engage a groove on the handle member that locks the magazine into place. Locking the magazine in place activates a sensor, thereby enabling the operation of the feeder. The interface securely engages the ACF so that the magazine cannot be accidentally dislodged from it. The magazine may be released from the feeder by pulling the handle forward, thereby activating the sensor which sends a signal to disable operation of the feeder. Pulling the handle forward also unlocks the magazine for easy removal. The handle may be extended for ease of carrying the magazine.

Data cartridge magazine with interface to automatic cartridge accessing

A magnetic tape has three evenly spaced-apart longitudinally-extending servo track areas. Four equal-sized longitudinally-extending data track areas are disposed between said servo track areas and between longitudinal edges of the tape and one of said longitudinally-extending data track areas. For track following, all servo track areas are simultaneously sensed for producing one head positioning signal. Data tracks are arranged into four groups of tracks, one-half of the data tracks in each group are concurrently accessed. The data tracks on the tape are arranged in clusters. Each cluster has one track from each of the groups of tracks. Two laterally-adjacent track clusters constitute four data track wraps for serpentine scanning of data tracks. The concurrent track accessing respectively occurs in first and second halves of a data track wrap (there is a number of wraps equal to one half the number of track clusters). Each servo area indicates two lateral positions of the tape to the head. The lateral spacing between the lateral positions is equal to about a data track width. This arrangement makes the servo areas field writable. The magnetic head has a number of data write and read gaps equal to the number of clusters. A set of four servo gaps are interposed between four groups of write and read gaps and positioned to simultaneously sense all three servo track areas.

Servo and data format for magnetic tape having plural spaced-apart servo

A magnetic tape drive simultaneously senses on a magnetic tape three evenly spaced-apart servo track areas for servoing a multi-track magnetic head to follow a concurrent set of data tracks on the magnetic tape. The data tracks are arranged into a plurality of track groups. Each track group has a first and second subgroup of data tracks. The first subgroup of tracks are scanned in a first relative motion of the magnetic tape and magnetic head as a forward direction (tape is being spooled from a supply tape reel). The second subgroup of tracks are scanned in a second relative motion of the magnetic tape and magnetic head that is opposite in direction to the first relative direction and is a forward direction of scanning. While writing data in any one of the plural track groups, a servo dropout affecting most of the servo track areas is detected and indicated as a servo error. Writing is aborted. The relative position of the magnetic tape and head is detected at both longitudinal ends of the servo dropout. A servo dropout block (SDB), a tape control block, is written at each longitudinal end of the servo dropout only in the group of tracks in which data are being written. The tape space between the two SDBs is termed a limited portion of the tape in which no recording is permitted.

Detecting a servo error on a magnetic tape and identifying extent and

A system uses prevent and detect mechanisms to enable rewritable data storage media to be operated as a written-once-only media. A physical indication of the media casing serves as an indicator of the write-once-only status of the media. A watermark is magnetically recorded on the media at the factory with a portion of the mark detectable by the system and a portion only detectable by returning to an inspection station for verification. This protects against a complete erasure of all data from the media. A segment write status indication serves to indicate the write-once-only status of each segment of the written data. A portion of the written region, such as the preamble or control field of each segment, contains a status mark written randomly within the area as a status indication that the data was written once or multiple times within that segment. Three status mark areas in each segment write status region provides the minimum space overhead for achieving the desired degree of protection against overwrite or a pattern repetition.

Rewritable media protectable as written-once-only media and system and

An adaptive equalization circuit for magnetic recording channels which derives an error signal to change the equalizer compensation value from the timing of random signal data and provides continuous feedback compensation.

Adaptive equalization circuit for magnetic recording channels utilizing

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Tucson, AZ, United States of America

David C Graves