Generating appendable points in encoded data

摘要

In a tape drive (800), a host interface (810) receives from a host computer host data to be compressed and stored to tape. The host interface (810) and also receives commands to create appendable points in the resulting compressed data stream. A data formatter (820) formats the received host data by encoding the data as codewords to form the compressed data stream, and co-operates with the host interface (810) by inserting into the compressed data stream special flush codewords at the requested appendable points. The formatter is also provided with the ability to insert flush codewords at positions determined by the host interface (810) itself. The codeword that follows a flush codeword is located at a pre-determined position relative to and after the flush codeword. Thus, appendable points are locatable by their respective flush codewords in the compressed data stream.