Abstract: A data reader is arranged to read data from a data-holding medium, said data being arranged into a plurality of data items each containing user data and non-user data, with said non-user data including one or more synchronisation fields. The data reader has a read head for reading a channel of said data-holding medium to generate a data signal comprising said data items, and processing circuitry arranged to receive and process said data signals to detect synchronisation fields, including qualifying the detection of the synchronisation fields to tolerate one or more errors in those synchronisation fields. This means that the synchronisation fields can be detected more reliably, so that more of the user data is recovered.

Abstract: A linear tape data storage device comprises a read head and a write head; a tape transport mechanism for transporting the linear tape data storage medium across the read head and the write head, the device being operated according to a predefined tape format; a DRAM buffer memory for storing data received during a write or a read operation; and error protection means configured to protect said data from soft errors generated by said buffer memory wherein the protection means comprises means for checking parity generated within the tape format itself. In the preferred embodiment the tape format used is the Linear Tape Open (LTO) format.

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, including write pass number information, and data items written across the said channels at the same time being identified as a set of data items, said data reader holding a current write pass number and having a read head 12 for reading a respective said channel of said data-holding medium 10 to generate a data signal comprising said data items, and processing circuitry 258, 280 arranged to receive and process said data signals of a set of data items, including processing said write pass number information of each of said data items in said set, and causing updating of said current write pass number held by said data reader on the basis of the write pass number information of said dat

Abstract: There is disclosed a method of accurately locating an append point along a length of linear tape data storage medium, comprising entering a search mode searching for an absolute code word quad set number, and having found the absolute code word quad set number, entering an interrupt mode for control of tape transport, followed by a write mode to write data at a data set containing the absolute code word quad set number.

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: A linear tape data storage device comprises a read head and a write head; a tape transport mechanism for transporting the linear tape data storage medium across the read head and the write head, the device being operated according to a predefined tape format; a DRAM buffer memory for storing data received during a write or a read operation; and error protection means configured to protect said data from soft errors generated by said buffer memory wherein the protection means comprises means for checking parity generated within the tape format itself. In the preferred embodiment the tape format used is the Linear Tape Open (LTO) format.

Abstract: A data reader is arranged to read data from a data-holding medium, said data being arranged into a plurality of data items each containing user data and non-user data, with said non-user data including one or more synchronisation fields. The data reader has a read head for reading a channel of said data-holding medium to generate a data signal comprising said data items, and processing circuitry arranged to receive and process said data signals to detect synchronisation fields, including qualifying the detection of the synchronisation fields to tolerate one or more errors in those synchronisation fields. This means that the synchronisation fields can be detected more reliably, so that more of the user data is recovered.

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: 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, including write pass number information, and data items written across the said channels at the same time being identified as a set of data items, said data reader holding a current write pass number and having a read head 12 for reading a respective said channel of said data-holding medium 10 to generate a data signal comprising said data items, and processing circuitry 258, 280 arranged to receive and process said data signals of a set of data items, including processing said write pass number information of each of said data items in said set, and causing updating of said current write pass number held by said data reader on the basis of the write pass number information of said dat

Abstract: There is disclosed a method of accurately locating an append point along a length of linear tape data storage medium, comprising entering a search mode searching for an absolute code word quad set number, and having found the absolute code word quad set number, entering an interrupt mode for control of tape transport, followed by a write mode to write data at a data set containing the absolute code word quad set number.