Example apparatus and methods provide a log structured block device for a hard disk drive (HDD). Data that is to be stored on an HDD is serialized and written as a series of data blocks using a sequential write. Information about where individual data blocks were supposed to be written (e.g., actual address, neighboring data blocks), where data blocks were actually written, and how often data blocks are accessed is maintained. During garbage collection, data blocks that are being accessed with similar frequencies may be relocated together, with the most frequently accessed (e.g., hottest) data blocks migrating to the outer cylinders of the disk and the least frequently accessed (e.g., coldest) data blocks migrating to the inner cylinders. Blocks stored in the same temperature regions that were intended to be located together when written may be repositioned to facilitate sequential reads.

Method and apparatus for enhancing write current switching efficiencies during data write operations in a data storage device. In some embodiments, write data are described in the form a sequence of symbols of nT length where T is a channel clock rate and n is an integer over a selected range. Bi-directional write currents are applied to a write element to record the sequence of symbols to a storage medium. The write currents are switched between a first rail current and a second rail current for alternating symbols. The write currents are further transitioned to an intermediate current value for at least one channel clock period immediately preceding a next occurrence of a symbol boundary between an adjacent pair of symbols in the sequence.

A code converting unit encodes input text data based on an code assignment table stored in a storage device that defines a conversion rule for encoding text data, wherein; the code assignment table being generated by assigning a part of character strings assigned to a 1-byte region of a first code assignment table to a 2-byte region of the code assignment table, and by assigning one or more codes each having two or more bytes to at least a part of character strings assigned to the 2-byte region of the code assignment table.

An object is to reduce the amount of data to be transmitted while ensuring tactile reproducibility. A decoding device according to the present technology includes: a first decoding unit that decodes first encoded data obtained by encoding a first signal section with a first bit rate, the first signal section being a part of a touch signal section which is a signal section indicating a touch state with an object in a tactile signal, the first signal section being a signal section including a boundary between the touch state and a non-touch state with the object; and a second decoding unit that decodes second encoded data obtained by encoding a second signal section with a bit rate lower than the first bit rate, the second signal section being a signal section except for the first signal section in the touch signal section.

A code converting unit encodes input text data based on an code assignment table stored in a storage device that defines a conversion rule for encoding text data, wherein; the code assignment table being generated by assigning a part of character strings assigned to a 1-byte region of a first code assignment table to a 2-byte region of the code assignment table, and by assigning one or more codes each having two or more bytes to at least a part of character strings assigned to the 2-byte region of the code assignment table.

In one embodiment, a method includes writing data to a storage medium, via a write channel, by applying a partial reverse concatenated modulation code to the data prior to storing encoded data to the storage medium. The applying the partial reverse concatenated modulation code to the data includes application of a C2 encoding scheme to the data to produce C2-encoded data prior to application of one or more modulation encoding schemes to the C2-encoded data to produce modulated data, followed by application of a C1 encoding scheme to the modulated data subsequent to the application of the one or more modulation encoding schemes to produce the encoded data.

Circuits that are matched to balanced codes may recover transmitted information in a noise resilient and power efficient manner. Circuit components for processing a balanced code may include one or more of: matched amplification of the signals representing the balanced code, matched equalization and/or filtering on the signals representing the balanced code, matched non-linear filtering on the signaling representing the balanced code to detect the presence of particular symbols and matched latching of the signals representing the balanced code. Such matched circuits and circuit components may be achieved at least in part by incorporating suitable common circuit nodes and/or a single energy source into circuit topologies.

In one embodiment, a data storage system includes a write channel for writing data to a storage medium, the write channel configured to utilize a partial reverse concatenated modulation code. The write channel includes logic adapted for encoding data sets using a C2 encoding scheme, logic adapted for adding a header to each subunit of the data sets, logic adapted for encoding the headers of the data sets with a first modulation encoding scheme, logic adapted for encoding data portions of the data sets with a second modulation encoding scheme, logic adapted for encoding portions of the one or more C2-encoded data sets using a C1 encoding scheme, logic adapted for combining the C1-encoded portions with the modulation-encoded headers of the C2-encoded data sets using a multiplexer, and logic adapted for writing the one or more combined C1 - and C2-encoded data sets to data tracks.

A code converting unit encodes input text data based on an code assignment table stored in a storage device that defines a conversion rule for encoding text data, wherein; the code assignment table being generated by assigning a part of character strings assigned to a 1-byte region of a first code assignment table to a 2-byte region of the code assignment table, and by assigning one or more codes each having two or more bytes to at least a part of character strings assigned to the 2-byte region of the code assignment table.

An object is to reduce the amount of data to be transmitted while ensuring tactile reproducibility. A decoding device according to the present technology includes: a first decoding unit that decodes first encoded data obtained by encoding a first signal section with a first bit rate, the first signal section being a part of a touch signal section which is a signal section indicating a touch state with an object in a tactile signal, the first signal section being a signal section including a boundary between the touch state and a non-touch state with the object; and a second decoding unit that decodes second encoded data obtained by encoding a second signal section with a bit rate lower than the first bit rate, the second signal section being a signal section except for the first signal section in the touch signal section.