Abstract: Example color resources are generated. A first luminosity amount of a greyscale color in a greyscale color space is determined. The greyscale color corresponds with a transformation of a source color in a first color space converted to the greyscale color. The source color corresponding with a depletion color in a second color space, and the depletion color has a second luminosity amount. A target color in a color resource is generated via adjusting a black channel amount in the depletion color to match the second luminosity amount with the first luminosity amount. The target color to correspond with the source color in the color resource.

Abstract: There is disclosed a method and apparatus for mapping between logical and physical addresses in a solid state data storage device, particularly but not exclusively a magnetic random access solid state data storage device, in which a list of mappings between ranges of logical addresses and ranges of physical addresses are stored in a data table, the mappings being operated on to look up a physical address from a logical address and vice versa, and being operated on by a data processor, to amend the data mappings by introduction of new ranges of logical and physical addresses, upon ranges of individual physical memory elements becoming defective.

Abstract: A network layer bridge includes: plurality of ports for connection to different network segments, a first port and a second port for connection to respective first and second network segments; a memory for storing network layer addresses for nodes with corresponding port identifiers and data link layer addresses, and data link layer addresses of more than one type; and a unit for discovering corresponding port identifier and data link layer address for a network layer address. The bridge forwards a message from a first node to a second node when corresponding port identifiers and data link level addresses for both first and second nodes are stored in the memory; the message being addressed with the network layer address of the second node, and the network layer bridge directing the message through the corresponding port to the corresponding data link level address for the second node.

Abstract: Requests to send data from a first host within a network of hosts are monitored against a record of destination hosts who have been sent data in accordance with a predetermined policy. Destination host identities not the record are stored in a buffer. The buffer size is monitored to establish whether requests from the first host are pursuant to viral activity therein.

Abstract: A tape drive method and apparatus is disclosed wherein payload data is sent from a host computer device to a tape drive data storage device in data block sizes which are specified by the host computer, for example in the case of a tape drive presenting a CD-ROM image, in 2 kbyte blocks, whereas the tape drive writes to tape media in an optimal block size required to keep the tape media streaming across the tape heads, for example 8 kbyte blocks. Conversion between block size is achieved by buffering incoming payload data in a buffer, and by reading or writing to the tape media in the optimum block size.

Abstract: A sequence of data blocks written onto a medium of a data storage system includes first and subsequent appended data blocks having an append point code for identifying the first appended data block location. For data blocks having a running block number or frame number, the block or frame number of the first appended data block is stored as the append point code. The appended point code identifies the most recently append point location and aids in processes, such as tracking calibration, data integrity confirmation and track positioning.

Abstract: A method of determining a value for a function that is particularly useful for mapping values from one color space to another includes a series of steps, as follows. The method is applicable to n-dimensional spaces, but is particularly described for three dimensions. The first step is to establish a three dimensional lattice, the function having values at the lattice points. The next step is to record values of the function for a subset of the lattice points, the lattice points of the subset known value lattice points. These known value lattice points from a sparse lattice (preferably the sparse lattice points ate regularly spaced along orthogonal axes). A values of the function for a given lattice point is established by returning a weighted average of the values of one or more of four known value lattice points defining a tetrahedron touching or enclosing the given lattice point.

Abstract: A data reader is arranged to read data comprising user data and non-user data written across at least two channels of a data-holding medium, the data being arranged into a plurality of data items each containing user data and non-user data, with the non-user data holding information relating to the user data, including a header with information relating to the user data and header error detection information, and data items written across the channels at the same time being identified as a set of data items.

Abstract: A data reader is arranged to read data comprising user data 30 and non-user data 32, 34 written across at least two channels of a data-holding medium 10, said data being arranged into a plurality of data items 26 each containing user data and non-user data, with said non-user data holding information relating to said user data, said data reader having a read head 12 for reading a respective said channel of said data-holding medium 10 to generate a data signal 14 comprising said data items, and processing circuitry 250 arranged to receive and process said data signals to identify a set CCPset1 of said data items written at the same time onto different said channels. Identifying a set of data items written at the same time gives rise to the possibility of correcting header information for the data items in a set.

Abstract: An on-board computer system is accessible by means of a plurality of on-board computer workstations. Data files can be used on this system by transferring them from a personal computer to the on-board computer system and then enabling access to the data files in accordance with identification information inputted to the on-board computer system.

Abstract: A method of encoding a digital data stream for writing to a digital storage (DDS) format tape data storage medium comprises writing a byte stream to a preamble region, immediately preceding a user data region. The byte stream has a power spectrum substantially similar to a power spectrum of the user data region. An automatic gain control circuit responds to the preamble data stream in a substantially similar fashion to its response to the user data stream.

Abstract: A tape is associated with a semiconductor memory storing the end position of the last data of a data set recorded on the tape. The end location is stored in the memory before the last data are written to the tape. In a further operation mode, data identifying the location of one or plural successfully written data sets which have already been written to the tape are stored in the memory while user data are written to the tape.

Abstract: In a wireless network containing battery powered stations, one station is designated as a control point (CP). Each of the remaining stations has two operating modes: an active mode in which it receives and transmits messages, and an inactive or sleep mode which incurs reduced power consumption. The Control Point periodically transmits a beacon signal, and each station switches to its active mode to receive at least some of these beacon signals. A beacon signal may indicate that data is available for transmission to a particular station (from another station), in which case that particular station then broadcasts a message to indicate that it is awake and can receive messages.

Abstract: When a person first enters an unfamiliar work space, it is useful for that person to know what devices are present in the space and often the person will spend the first few minutes looking around, effectively carrying out an inventory of the devices present. In order to simplify this process the devices are arranged to announce their existence by sound in response to a prompt, such as a handclap. To avoid the announcements being made all at once in an unintelligible manner, the devices interact with each other to order their announcements so that each device announcement is, at least in due course, made uninterrupted by announcements from other devices. Typically, this interaction involves the devices using a collision-detection and back-off protocol applied to the announcements themselves.

Abstract: A headless computer entity has a license key data stored on a raw disk sector separate from a system disk and a data disk. The license key data control the available data storage capacity within the headless computer entity, and protect the computer entity from unauthorized upgrade to a higher product specification. The license key data are encrypted and protected from hacking via software updates introduced on an external data carrier, such as a CD ROM.

Abstract: A method for recovering user data from a host device stored on a data storage medium where a said data may become corrupted during a read operation comprises: performing a read operation to read at least one encoded data fragment of said plurality of encoded data fragments from said data storage medium; storing status data indicating whether said at least one data fragment was correctly read; writing said read at least one data fragment to a buffer memory; attempting to decode said at least one encoded data fragment in said buffer memory wherein if said attempted decoding is unsuccessful then said method further comprises the steps of: re-reading incorrectly read encoded data fragments from said data storage medium; and attempting to decode said encoded data fragments located in said buffer memory.

Abstract: In a digital data storage system providing two or more levels of interleaved Reed-Solomon error correction coding together with a track checksum, the track checksum is calculated according to an algorithm which has no correlation with the Reed-Solomon codeword generation rules. This allows miscorrections at the C2 correction level to be determined reliably thereby enhancing the correction rate. Also disclosed is a system which uses the enhanced ability to identify C2 miscorrections, to mark C2 miscorrections to the third level of error correction thereby allowing double error correct at the third level.

Abstract: Diagnostic data in a sequential access Small Computer System Interface device is accessed by a first logical unit. A second logical unit is configurable to control a mode of operation of the first logical unit. The first unit Provides normal and/or backup functions while the second unit provides diagnostic/status functions or the second unit activates the first unit to be online or offline, depending on the first unit being commanded to perform the diagnostic function.

Abstract: From a set of possible switching states and responsive to a sequence of measurements, a corresponding sequence of switching states is determined for a system having a plurality of dynamic models, associates each model with a switching state such that a model is selected when its associated switching state is true. A state transition record is determined, based on the measurement sequence. The sequence of switching states is determined by backtracking through the state transition record. Alternatively, the switching state model is decoupled from the dynamic system model. The decoupled switching state model is transformed into a hidden Markov model (HMM) switching state model, while the decoupled dynamic system model is transformed into a time-varying dynamic system model. A solution to the dynamic system model is estimated using a Kalman filter.