Partial reverse concatenation for data storage devices using composite codes

A tape drive, comprising:

• a magnetic head;
• a controller in communication with the magnetic head;
• drive motors configured to move a tape over the magnetic head;
• guides configured to guide the tape across the tape head;
• and
• logic integrated with a processor, executable by the processor, or integrated with and executable by the processor, the logic being configured to cause the processor to:
• receive, by the processor, a data stream comprising data sets;
• encode, by the processor, the data sets using a C2 encoding scheme to produce C2-encoded data sets;
• assign, by the processor, the data sets to K data tracks, where K is at least 8;
• divide, by the processor, each of the C2-encoded data sets into a plurality of subunits;
• add, by the processor, a header to each subunit of the C2-encoded data sets after encoding the data sets using the C2 encoding scheme;
• in K parallel processing channels, each associated with a unique one of the data tracks, for processing the respective data sets assigned to the data track associated with the particular processing channel:
• encode in each channel, by the processor, the headers of the headerized data sets with a first modulation encoding scheme after adding the header to each of the C2-encoded data sets;
• encode in each channel, by the processor, data portions of the headerized data sets with a second modulation encoding scheme after adding the headers to each of the C2-encoded data sets;
• encode in each channel, by the processor, the data portions of the modulation-encoded data sets using a C1 encoding scheme after encoding the data portions of the headerized data sets with the second modulation encoding scheme;
• and
• combine in each channel, by the processor, a C1-encoded data portions with the modulation-encoded headers of the data sets;
• and
• write, by the magnetic head, combined C1- and C2-encoded data sets to K simultaneously-written data tracks of a magnetic tape,
• wherein the data sets are encoded using the C2 encoding scheme before any portion of the data sets are encoded using any of:
• the first modulation encoding scheme, the second modulation encoding scheme, and the C1 encoding scheme.