Abstract: Disclosed is a digital edge processor frequency control for estimating the center frequency of a recorded signal having a known format, such as data recorded on a CLV optical disk or on magnetic tape. The read channel includes a sampling detector which samples the recorded signal at a known rate to provide edge position signals (PAT) indicating the location of recorded pulse edges. An edge pattern identifier detects whether the edge signals of the recording signal match a predetermined element of the known format. Examples of predetermined elements include a pulse of a known length and whose edges are spaced a known distance, a predetermined pulse pattern, or a pulse or pattern at a known location. An interval counter is coupled to the pattern identifier for measuring the interval length between the edges of the matching pulse or pattern in units of the sample length.

Abstract: Disclosed is a compliant edge guiding and following system for recording tape. Two tape bearings are provided which define a tape path, each having a bearing surface for supporting lengthwise travel of the recording tape along the tape path. A movable tape head is positioned in the tape path between the tape bearings. The movable tape head includes a track following servo for moving the head laterally to follow lateral movement of the recording tape and maintain alignment therewith. A set of compliant tape edge guides are positioned at opposite edges of the tape path. The compliant tape edge guides of the set are a matched pair and are spaced apart laterally a distance substantially equal to the nominal width of the recording tape and positioned substantially equidistant from the centerline of the tape path. Separate sets may be positioned in the lengthwise direction on each side of, and each set closely spaced from, the movable tape head.

Abstract: In an optical data storage device for storing data on a removable optical disk in a continuous sequence of sectors or blocks, the input data buffer may be subject to under-run. An under-run detector is disclosed which is responsive to the buffered data comprising less than a sector of data for indicating an under-run, and a padding provider is disclosed which is responsive to the under-run indication for providing padding characters for formatting into sectors. The sectors may be provided with headers indicating the sectors as padding. A reading device for reading the data sectors and providing the data to a host detects padding and prevents the padding data from transmission to the host.

Abstract: A bonding opening exposing conductors through a cover of a multiconductor flat cable or electrical component to allow direct bonding thereof is described. The multiconductor flat cable or electrical component having a base layer with conductors disposed thereon and a flat cover having an opening provided therein at a bonding site, preferably by die cutting. The flat cover with the opening is laminated to the base layer, overlaying the conductors, so that the conductors are mechanically stabilized by the base layer while being exposed through the bonding opening. The shape of the multiconductor flat cable or electrical component of the present invention may be highly varied. In one embodiment, the flat multiconductor electrical component circumferentially extends around a central area, for example, totally encompassing in IC chip which may be connected to the conductors thereof at a bonding site.

Abstract: Disclosed is a combined pass through and load/unload system for automated data storage libraries. Separate portals open into each of the libraries. A pivoting robot supports a housing which is capable of supporting at least one removable multi-cartridge magazine, and pivots about a pivot axis. An actuator withdraws or extends the housing toward or away from the pivot axis. A pass through controller operates the pivoting robot to position the housing at a portal and operates the actuator to extend the housing into the portal so that the library may load and/or unload the data storage media into or out of the removable magazine(s) in the housing. The controller then operates the actuator and robot to withdraw the housing out of the portal. The controller may position the housing at the bulk load/unload position so an operator may unload and/or load magazines from the housing. The controller may position the housing at the portal of the other library to allow the transfer of media thereto.

Abstract: A data storage system is described which allows data storage devices with different characteristics, such as differing data rates and transfer speeds, to be connected, and intermixed, along a single data and communication link. The data storage system comprises a storage controller, a first data storage device, a second data storage device, and a data and communication link coupled therebetween. The storage controller transfers data to and from the first data storage device using data locations within the data and communication link to transfer a data byte, a parity location to transfer the associated parity bit, and a communication signal location to transfer a data clocking signal. The storage controller further transfers data to and from the second data storage device using the data locations to transfer a data byte and the parity location to transfer a data clocking, or a data strobe, signal.

Abstract: Disclosed is a mounting structure for mounting a horizontal insertion loading data storage drive in a data storage library having downwardly inclined shelves. A bracket mounts the data storage drive, and support bars are mounted in parallel in the data storage library and support the bracket on each side at a downwardly inclined angle. Thus, the horizontal insertion loading data storage drive is mounted at the downwardly inclined angle to receive data storage media from a robot accessor at the angle of the downwardly inclined shelves. The mounting structure support bars are parallel slides which slidably support the bracket at the downwardly inclined angle. A ratchet bar is mounted in the library at the downwardly inclined angle, and has a plurality of ratchet holes in the downwardly inclined direction. A latch is mounted on the bracket for engaging the ratchet holes of the ratchet bar to support the bracket and data storage drive against sliding on the support bar slides.

Abstract: A virtual data storage system provides a method and apparatus for premigrating host-originated data files initially stored in a cache storage to selected storage volumes within a storage subsystem. A premigration list includes an entry for each cache data file eligible to be premigrated, or copied, to the storage subsystem. Each entry includes a data file identifier, a cache storage location, and a premigration delay criterion. The purpose of the premigration delay criterion is to ensure that the data files are written to the storage subsystem in a timely manner, but to also allow the host processing system to subsequently re-access data files written to the virtual data storage system without interference and delay from the premigration process. The cache data files are not premigrated until the corresponding premigration delay criterion has elapsed, or exceeded a predetermined threshold.

Abstract: Disclosed are a method and processor external to an automated data storage library for partitioning the data storage library into multiple virtual libraries for access by a plurality of hosts, each host having a host port, the data storage library having a plurality of data storage drives, a plurality of storage slots, a library controller, the library controller identifying each of the data storage drives and the storage slots, a library port coupled to the library controller, and at least one accessing robot controlled by the library controller, comprising the steps of, at a node intermediate the library port and host ports, inquiring of the host ports to identify the number of host ports; inquiring, via the library port, of the library controller to determine the data storage drive identifiers and the total number of the storage slots; identifying by employing the data storage drive identifiers, the data storage drives associated with each host port; and sequentially creating virtual libraries, assigning t

Abstract: A low profile tape cartridge has a reel which rotates within an outer protective shell. The reel has flanges which define a slot containing a roll of magnetic tape. The shell only surrounds the reel along its circumference and the flat upper and lower surfaces of the flanges are exposed. When assembled, the reel and shell have axial thicknesses which are substantially equal. The shell moves between locked and unlocked positions for engaging and disengaging the reel. The cartridge uses and fits within a shell retainer for creating uniform spacing around the reel when the shell is in the unlocked position. The tape is accessed by loading a cartridge into the retainer in a tape drive. The tape drive unlocks the shell to rotate the reel and extract the tape. After use, the tape is retracted onto the reel and the cartridge is then returned to the locked position.

Abstract: A storage and retrieval library has a column of storage cells including at least some side-by-side storage cells. A media accessor with a picker gripper for accessing media in one side of the side-by-side cells is rotatable about a pivot to an opposed position for accessing media in the other side of the side-by-side cells. For multi-sized media, a column may have storage cells extending the full width of the column for holding a large sized media, and a second type of smaller cells arranged side-by-side, each for holding a small sized media. A media picker has a first gripper for accessing large sized media from the full width cells, and a second gripper for accessing small sized media from one side of the side-by-side cells. The media picker is rotatable about a pivot to an opposed position for the second gripper for accessing small sized media from the other side of the side-by-side cells.

Abstract: A device controller is described within a data storage system for pre-fetching device work information from multiple data storage devices, and accumulating the device work information to immediately respond to a subsequent device poll command from a storage controller. The device controller includes a device receiver to receive the device poll command, a device transmitter to transmit a response to the device poll command, a device information register for storing the pre-fetched device work information for each data storage device, and a sequencer for periodically pre-fetching the device work information from each data storage device. The sequencer pre-fetches such information by verifying that no device subsystem command from the storage controller is pending in the device receiver, then issuing a background poll command to a selected device to query the device for its device work information, and storing the device work information in the device information register.

Abstract: Disclosed are an automated data storage library and a method for operating the library. The library includes two pickers arranged on a common guideway; a plurality of media storage slots arranged in a plurality of regions alongside the guideway; a plurality of read/write stations arranged in regions alongside the guideway. Commands are received for jobs to move media amongst the storage slots and the read/write stations, and a controller queues the received commands and allocates the queued commands to the pickers and in an order of jobs which will allow the pickers to independently access and move the media so as to avoid interference in the same region, or in regions which are behind the other picker. The media storage slots may be arranged in row sets and regions alongside the guideway, each row set including one or more storage slots and each region including one or more columns, with the regions narrower than the pickers.

Abstract: Disclosed is an automated data storage library for storing and retrieving data storage media in a plurality of storage slots, for a host processor. At least one drive unit is coupled to the host processor for reading and/or writing data on the data storage media. A library manager includes a stored table for identifying the data storage media stored in the storage slots, the stored table indicating artificial scaling of the data storage capacity of selected data storage media to selected values less than the actual data storage capacity thereof. The stored table also stores indicators of attributes of the library with respect to ones of the data storage media, such as indicating that the drive unit is to communicate at the drive/host interface in a specific protocol.

Abstract: A fan venturi blockage detector for a DC electric fan and an associated method are disclosed employing a current detector for measuring the input current to the DC electric fan, and a processor connected to the current detector. The processor stores the measured input current value for the minimum input current to the fan under normal operating conditions, and sets a minimum current threshold at a value less than the normal operating condition measured current. The processor compares subsequent measured input current values with the minimum current threshold value, and provides an error signal upon the subsequent measured input current having a value equal to or less than the minimum current threshold value.

Abstract: Disclosed is a memory array system, such as a DRAM, for the temporary storage of data. ECC check symbols for insuring the correctness of the data are written to a different segment of the memory array from the data. The data is formatted into blocks of length (l), directly related to the standard sized access width of the memory array, and gap blocks of length (l) are inserted into the data stream for subsequent substitution of headers. The data and associated headers may have appended check symbols calculated with a Reed-Solomon generator polynomial. The data blocks are written into memory partitions with an exact alignment of blocks with partition boundaries, so that no gap block spans a partition boundary. ECC encoding logic calculates the ECC check symbols, employing an identical Reed-Solomon generator polynomial for each partition. The headers with the associated CRC are subsequently substituted for the gap blocks.

Abstract: Disclosed are a method and apparatus for switching between lossless data compression modes, and the switching indicated by at least one multibit mode switch character. The binary format input data is received and a FIFO determination of the compression efficiency of the input data under each mode is made on an ongoing basis. The ongoing basis may be for each compressed code word or more. A FIFO comparison of the compression efficiencies under each mode are made, and the modes for compressing the input data are switched only upon the comparison, or accumulated comparisons, indicating the compression efficiency of the present mode is less than the compression efficiency of the other mode by a threshold value, the threshold value directly related to the number of bits in the multibit mode switch character.

Abstract: An automated library is disclosed for storing and retrieving data storage cartridges having a plurality of rotatable stacks, all rotatable about parallel axes, each stack being multi-faced and preferably rectangular. A column of cells for storing data cartridges is provided in each of at least two of the faces of the rectangular stacks, and the columns of cells are aligned parallel to the axis of the associated stack. At least one read/write drive is provided for reading and/or writing the data storage cartridges, and preferably a read/write drive is provided at the base of each rotatable stack. A picker is rotatable about an axis parallel to the axes of the rotatable stacks, for accessing the data storage cartridges stored in the cells, and for transporting the cartridges between the cells and a read/write drive. Servo systems rotate the rotatable stacks and the rotatable picker into mutually facing positions for accessing the cells of columns of the stacks with the rotatable picker.

Abstract: Disclosed is an error tolerant binary encoded synchronization mark concatenated with a known pattern, such as a VFO pattern, comprising an encoded pattern of a fixed plurality of bits, the encoded synchronization pattern being at maximum Hamming distance from the concatenated known pattern for the number of bits in the fixed plurality of bits. The error tolerant synchronization mark may also be concatenated with the VFO pattern seen in reverse, and the synchronization pattern additionally is at maximum Hamming distance from the concatenated known VFO pattern seen in reverse.

Abstract: The invention is a positive peak level comparator for generating a positive peak pulse when a TES (Tracking Error Signal) is higher than a predetermined positive level, a negative peak level comparator for generating a negative peak pulse when the TES is lower than a predetermined negative level, and a logic circuit for generating an output pulse when said positive peak pulse and said negative peak pulse have been alternately input thereto. The arrangement prevents the TES from being miscounted even if the TES is distrubed due to the occurrence of, for example, a noise at a level close to either said predetermined positive level or said predetermined negative level and either said peak pulse or said negative pulse is successively generated.