Abstract: In a tape drive, or other storage device, used for storing computer data, both record data and record structure information such as file marks are encoded with codewords to form an encoded data stream. Of the fixed number of possible fixed-length codewords, one codeword is assigned as a root sequence for one or more longer codewords. Thus, detection of the root sequence during decoding of an encoded data stream triggers the reading of a fixed number of further bits. The further bits represent file marks and any other defined information. In the tape drive (800), the tape drive interface (810) receives record data and file mark commands. The formatter (820) encodes the record data as fixed length codewords.

Abstract: In a tape drive used for storing computer data, both record boundary data and data separation commands, such as Write File Mark commands, are encoded with codewords to form a continuous, encoded data stream. In such a tape drive, a tape drive interface receives the record data and data separation commands and, transmits the record data to a tape drive formatter to encode the record data into a continuous encoded data stream and signals the formatter when data separation commands are received. In response to signals from the tape drive interface, the formatter generates control codewords and embeds them into the continuous encoded data stream, and the data stream is stored in a buffer.