Data compression for recording on a record medium

• US 5,097,261 A
• Filed: 11/19/1990
• Issued: 03/17/1992
• Est. Priority Date: 11/22/1989
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Langdon, Glen G. Jr., Miller, Robert W., MacLean, Neil H. Jr., Patel, Mayank R.
• Primary Examiner(s): Williams, Howard L.
• Application Number:
  US07/615,665
• Time in Patent Office: 484 Days
• Field of Search: 341/51, 341/60, 341/55, 341/87, 341/95, 341/106, 341/107
• US Class Current: 341/51
• CPC Class Codes: G11B 20/00007 Time or data compression or expansion audio compression based on psychoacoustics G10L19/00; data processing for reproducing audio data at different playback speeds G10L21/04; video compression H04N19/00; data compression per se H03M7/30
• CPC Class Codes: H03M 7/4006 Conversion to or from arithmetic code
• CPC Class Codes: H04N 21/236 Assembling of a multiplex stream, e.g. transport stream, by combining a video stream with other content or additional data, e.g. inserting a URL [Uniform Resource Locator] into a video stream, multiplexing software data into a video stream; Remultiplexing of multiplex streams; Insertion of stuffing bits into the multiplex stream, e.g. to obtain a constant bit-rate; Assembling of a packetised elementary stream multiplexing of data packets for data networks, e.g. RTP/UDP H04L65/00
• CPC Class Codes: H04N 21/434 Disassembling of a multiplex stream, e.g. demultiplexing audio and video streams, extraction of additional data from a video stream; Remultiplexing of multiplex streams; Extraction or processing of SI; Disassembling of packetised elementary stream demultiplexing of data packets for data networks, e.g. RTP/UDP H04L65/00

Abstract

A tape drive system includes a compaction scheme whereby the data to be stored on the media is encoded and formatted to take less space along the tape length. The data to be written to tape is placed into equal byte lengths or sets. The sets of data are directed to a plurality of encoders in turn and compacted through an Arithmetic Binary Coding program having two statistic tables per encoder to allow format compatibility with a higher throughput compaction scheme. The compacted sets are sequenced and formed into packets. Then the packets are autoblocked to delineate the packets while providing a single Inter Block Gap per autoblock length and written on the tape. On read, the data is retrieved from the tape and deblocked to separate the packets. Each packet is separated into compacted sets of data. The compacted sets are directed to a plurality of decoders in turn and decompacted. The decompacted sets are to resequenced to place the data into the same state as originally transmitted.

Claims

1. A compaction system for use in compressing a stream of data from a host processing unit for storage onto a recording media comprising:

a first demultiplexer/multiplexer unit accepting the stream of data and separating the stream of data into sets of data of equal length, except for a remainder;

a plurality of encoders, each accepting one set of data in sequential order from said first demultiplexer/multiplexer unit, with each processing its set into a compressed set of data;

means for adding an identifying signal to each compressed set of data;

a second demultiplexer/multiplexer unit accepting the compressed sets of data from each of said plurality of encoders and for combining and resequencing the compressed sets into their original sequence as received by said first demultiplexer/multiplexer unit;

an autoblocking unit accepting the sequenced compressed sets of data to create a block of data from a plurality of the compressed sets and to add one data signal identifying a plurality of the blocks of compressed sets; and

a write formatter accepting the blocks of compressed sets of data for storage onto the recording media.

2. A compaction system as defined by claim 1, further decompressing compressed data and further including a plurality of decoders and a read data unit and wherein:

said read data unit retrieves the blocks of compressed sets of data from storage on the recording media;

said autoblocking unit accepting the blocks of compressed sets of data from the read data unit and removing the added data signals from the compressed sets of data;

said second demultiplexer/multiplexer unit accepting the compressed sets of data from said autoblocking unit and dividing the compressed sets into individual sets according to its identifying signal;

each of said plurality of decoders accepting one compressed set of data in sequential order and processing the set into a decompressed set of data;

said first demultiplexer/multiplexer unit accepting the decompressed sets from each decoder and reassembling the decompressed sets into the original sequence of the sets in the stream of data for transmission to the host processing unit.

3. A compaction system for use in compressing a stream of data from a host processing unit for storage onto a recording media comprising:

means, including a first demultiplexer/multiplexer unit, for creating sets of data of equal length and a remainder, if required, from the stream of data received from the host;

means including a plurality of encoders for compacting the sets of equal length data with each encoder in sequence handling a set of data and processing the set into a compressed set of data;

means, including a second demultiplexer/multiplexer unit, for resequencing the compressed sets of data from said compacting means;

means for autoblocking the resequenced compressed sets to add one data signal identifying a block of data formed by said autoblocking means from a plurality of the compressed sets;

means for transferring the block of data for writing onto the media.

4. A compaction system as defined by claim 3, further including a plurality of decoders and a read data unit and wherein:

said read data unit retrieves the blocks of compressed sets of data from storage on the recording media;

said autoblocking means accepts the blocks of compressed sets of data from the read data unit and deblocks and removes the added data signals from the compressed sets of data;

said second demultiplexer/multiplexer unit accepting the compressed sets of data from said autoblocking unit and dividing the compressed sets into individual sets according to its identifying signal;

each of said plurality of decoders accepting one compressed set of data in sequential order and processing the set into a decompressed set of data;

said first demultiplexer/multiplexer unit accepting the decompressed sets from each decoder and reassembling the decompressed sets into the original sequence of the sets in the stream of data for transmission to the host processing unit.

5. A compaction system for use in compressing a stream of data from a host processing unit for storage onto a recording media comprising:

demultiplexing means for creating sets of data of equal length and a remainder from the stream of data received from the host;

four encoding means for encoding the data sets into compressed sets of data, each of said encoding means accepting one set from the sequence of the plurality of sets from said demultiplexing means;

each of said encoding means including two statistic tables, one accessed by its associated encoding means in sequence, such that all eight statistic tables are accessed in sequence, once for every eighth set, to create an eight statistic table format for the encoding process;

multiplexing means for combining the compressed sets from said form encoding means to resequence the compressed sets of data into its original sequence before compression;

autoblocking means for accepting the resequenced compressed sets of data for creating a block of data from a plurality of the compressed sets and for adding one data signal identifying a plurality of the blocks of compressed sets;

means for writing the blocks of compressed data onto the recording media;

means for retrieving the blocks of compressed data from the recording media at the request of the host processing unit; and

four decoding means for decoding compressed sets of data into its original set of data each of said decoding means including two statistic tables, one accessed by its associated decoding means in sequence, such that all eight statistic tables are accessed in sequence, once for every eighth set, to permit decoding using the eight statistic table format used for the encoding process;

wherein said autoblocking means unblocks the blocks of compressed data into the compressed sets of data before blocking;

wherein said multiplexing means acts as a demultiplexing means for separation of the compressed sets of data into individual sets for decoding by said decoding means in sequence; and

wherein said demultiplexing means acts as a multiplexing means for resequencing the decompressed packets of data from said form of decoding means for use by the requesting host processing unit.

6. A compaction system for use in compressing a stream of data for storage comprising a compaction unit and an autoblocking unit;

said compaction unit including separating means for separating the stream of data into sets of data of equal length, except for a remainder and including a plurality of encoders, each accepting one set of data in sequential order with each processing its set into a compressed set of data and means for adding an identifying signal to each compressed set of data, and further including combining means for accepting the compressed sets of data from each of said plurality of encoders and for combining and resequencing the compressed sets into their original sequence as received;

said autoblocking unit accepting the sequenced compressed sets of data to create a block of data from a plurality of the compressed sets and to add one data signal identifying a plurality of the blocks of compressed sets; and

storage means connected to receive the compressed sets of data as placed into blocks of data and identified by said autoblocking unit for storing the blocks of data.

7. A compaction system as defined by claim 6 further including a plurality of decoders for decompressing compressed data and wherein:

said autoblocking unit receiving the blocks of compressed sets of data from said storage means and removing the added data signals from the compressed sets of data and further separating the blocks of data into the compressed sets of data;

said combining means adapted to separate the compressed sets of data into individual compressed sets;

each of said plurality of decoders accepting one compressed set of data from said combining means in sequential order and processing the set into a decompressed set of data;

said separating means accepting the decompressed sets from each decoder and adapted to reassemble the decompressed sets into the original sequence of the sets in the stream of data.

8. A compaction system as defined in claim 7 wherein said plurality of encoders and decoders are each four in number.

9. A compaction system as defined in claim 8 wherein a modulo eight count is set for sequencing the sets of data for compression and decompression by said encoders and decoders, with the four encoders and decoders receiving every fourth set of data and repeating as necessary until all of the sets of data and any remainder of data is compressed and decompressed as needed.

10. A compaction system as defined in claim 9 wherein the sets of data compacted by one encoder of the four encoders is decompacted by one decoder, companion to the one encoder, of the four decoders.

11. A compaction system for use in compressing a stream of data for storage comprising:

means for creating sets of data of equal length and a remainder, if required, from the stream of data received;

means including a plurality of encoders for compacting the sets of equal length data with each encoder in sequence handling a set of data and processing the set into a compressed set of data;

means for resequencing the compressed sets of data from said compacting means;

means for autoblocking the resequenced compressed sets to add one data signal identifying each block of data formed by said autoblocking means from a plurality of the compressed sets;

storage means connected to receive the blocks of data and the identifying signal for storage.

12. A compaction system for use in compressing a stream of data for storage comprising:

demultiplexing means for creating sets of data of equal length and a remainder from the stream of data;

four encoding means for encoding the data sets into compressed sets of data, each of said encoding means accepting one set and every fourth set thereafter from the sequence of the plurality of sets from said demultiplexing means and operating under a modulo eight sequence;

each of said encoding means including two statistic tables, one accessed by its associated encoding means in sequence, such that all eight statistic tables are accessed in sequence, once for every eight set under the modulo eight sequence, to create an eight statistic table format for the encoding process;

multiplexing means for combining the compressed sets from said four encoding means to resequence the compressed sets of data into its original sequence before compression;

autoblocking means for accepting the resequenced compressed sets of data for creating at least one block of data from a plurality of the compressed sets and for adding one data signal identifying each of the blocks of compressed sets; and

storage means connected to receive the blocks of compressed data for storage;

means for retrieving the blocks of compressed data from said storage means for transmittal to said autoblocking means; and

four decoding means for decoding compressed sets of data into its original set of data each of said decoding means including two statistic tables, one accessed by its associated decoding means in sequence, such that all eight statistic tables are accessed in sequence, once for every eight set under the modulo eight sequence, to permit decoding using the eight statistic table format used for the encoding process;

wherein said autoblocking means unblocks the blocks of compressed data received from said storage means into the compressed sets of data before blocking;

wherein said multiplexing means acts as a demultiplexing means for separation of the compressed sets of data into individual sets for decoding by said decoding means in sequence; and

wherein said demultiplexing means acts as a multiplexing means for resequencing the decompressed packets of data from said decoding means.

13. A compaction system as defined in claim 12 wherein the sets of data compacted by one encoding means of the four encoding means is decompacted by one decoding means, companion to the one encoding means, of the four decoding means.

14. A control unit connected to receive data and commands from a central processing unit for storing the data in a storage means, said control unit comprising adaptors for the transmission of data and commands to and from the central processing unit under command control of the central processing unit, a command unit to process the command controls, a compaction system for compressing the data, and a format control;

said compaction system including a compaction unit and an autoblocking unit;

said compaction unit including separating means for separating the stream of data into sets of data of equal length, except for a remainder, and a plurality of encoders, each accepting one set of data in sequential order with each processing its set into a compressed set of data, and further including means for adding an identifying signal to each compressed set of data, and combining means for accepting the compressed sets of data from each of said plurality of encoders and for combining and resequencing the compressed sets into their original sequence as received by said compaction unit;

said autoblocking unit accepting the sequenced compressed sets of data to create a block of data from a plurality of the compressed sets and to add one data signal identifying a plurality of the blocks of compressed sets;

said format control accepting the blocks of compressed sets of data from said autoblocking unit and for writing the compressed data into said storage means;

said command unit activating said compaction system, said format control and the storage means to process the data flow from the adaptors through said compaction system and said format control to write the blocks of compressed data into the storage means for storage therein.

15. A control unit as defined in claim 14 wherein said compaction unit further includes a plurality of decoders and wherein:

said format control under control of said command unit received the blocks of compressed data from the storage means as requested by the central processing unit;

said autoblocking unit deblocking the blocks of compressed sets of data from said format control and removing the added data signals from the compressed sets of data;

said combining means accepting the compressed sets of data from said autoblocking unit and further adapted to divide the compressed sets into individual sets according to its identifying signal;

each of said plurality of decoders accepting one compressed set of data in sequential order and processing the set into a decompressed set of data;

said separating means accepting the decompressed sets from each decoder and adapted for reassembling the decompressed sets into the original sequence of the sets in the stream of data;

said adaptors receiving a read command from the central processing unit and said command unit responsive thereto to activate said storage means to retrieve the stored blocks of compressed data, the blocks of compressed data being directed to said format control for processing.

16. A control unit as defined in claim 15 wherein said plurality of encoders and decoders are each four in number.

17. A control unit as defined in claim 16 wherein a modulo eight count is set for sequencing the sets of data for compression and decompression by said encoders and decoders, with the four encoders and decoders receiving every fourth set of data and repeating as necessary until all of the sets of data and any remainder of data is compressed and decompressed as needed.

18. A control unit as defined in claim 17 wherein the sets of data decompacted by one encoder of the four encoders is decompacted by one decoder, companion to the one encoded, of the four decoders.

19. A control unit as defined in claim 15 further including means controlled by said command unit for bypassing said compaction unit when compaction is not required on the data received by said adaptors.

20. A data processing system for compressing data from a central processing unit for storage on a media comprising:

a control unit including adaptors for the transmission of data and commands to and from the central processing unit under command control of the central processing unit, a command unit to process the command controls, a compaction system for compressing the data, and a format control; and

a device including a drive for transporting the media past a transducer, a motion control under control of said command unit for controlling said drive, and a data control to activate the transducer to write data onto the media and to retrieve data from the media as the drive transports the media;

said compaction system including a compaction unit and an autoblocking unit;

said compaction unit including separating means for separating the stream of data into sets of data of equal length, except for a remainder, and a plurality of encoders, each accepting one set of data in sequential order with each processing its set into a compressed set of data, and further including means for adding an identifying signal to each compressed set of data, and combining means for accepting the compressed sets of data from each of said plurality of encoders and for combining and resequencing the compressed sets into their original sequence as received by said compaction unit;

said autoblocking unit accepting the sequenced compressed sets of data to create a block of data from a plurality of the compressed sets and to add one data signal identifying a plurality of the blocks of compressed sets;

said format control accepting the blocks of compressed sets of data from said autoblocking unit and transmitting the compressed sets of data to said data control for writing the compressed data onto the media under control of said command unit;

said command unit activating said motion control to control said drive and activating said compaction system and said format control to process the write data flow from the channel adaptors through said compaction system, said format control and said data control to write the blocks of compressed data onto the media for storage thereon.

21. A data processing system as defined in claim 20 wherein said compaction unit further includes a plurality of decoders and wherein:

said autoblocking unit deblocking the blocks of compressed sets of data received from the read data unit and removing the added data signals from the blocks of compressed sets of data;

said combining means accepting the compressed sets of data from said autoblocking unit and further adapted to divide the compressed sets into individual sets according to its identifying signal;

each of said plurality of decoders accepting one compressed set of data in sequential order and processing the set into a decompressed set of data;

said separating means adapted for accepting the decompressed sets from each decoder and reassembling the decompressed sets into the original sequence of the sets in the stream of data for transmission to said adaptors;

said adaptors receiving a read command from the central processing unit and said command unit responsive thereto to activate said motion control of said device to transport the media past the transducer to read the compressed data from the media, the compressed data being directed to said data control and said format control for processing and to said autoblocking unit of said compaction system for decompression.

22. A compaction system as defined in claim 21 wherein said plurality of encoder and decoders are each four in number.

23. A compaction system as defined in claim 22 wherein a modulo eight count is set for sequencing the sets of data for compression and decompression by said encoders and decoders receiving every fourth set of data and repeating as necessary until all of the sets of data and any remainder of data is compressed and decompressed as needed.

24. A compaction system as defined in claim 23 wherein the sets of data compacted by one encoder of the four encoders is decompacted by one decoder, companion to the one encoder, of the four decoders.

25. A data processing system as defined in claim 20 wherein said media is a magnetic tape media.

26. A data processing system as defined in claim 25 wherein said magnetic tape media is stored on a reel in a cartridge and said drive is adapted to remove the media from the cartridge by a threading mechanism which directs the media to a take-up reel past said transducer under control of said motion control, and includes drive motors to rotate the cartridge reel and the take-up reel, with both drive motors being controlled by said motion control as signalled by the tachometers connected to each drive motor and the tape tension device.

27. A data processing system for compressing data from a central processing unit for storage on a media comprising:

a control unit including channel for the transmission of data to and from the central processing unit under command control of the central processing unit, a command unit to process the command controls, a compaction system for compressing the data, and a format control; and

a device including a drive for transporting the media past a transducer, a motion control under control of said command unit for controlling said drive, and a data control to activate the transducer to write data onto the media and to retrieve data from the media as the drive transports the media;

said compaction system including a first demultiplexer/multiplexer unit accepting the stream of data and separating the stream of data into sets of data of equal length, except for a remainder;

a plurality of encoders, each accepting one set of data in sequential order from said first demultiplexer/multiplexer unit, with each processing its set into a compressed set of data;

means for adding an identifying signal to each compressed set of data;

a second demultiplexer/multiplexer unit accepting the compressed sets of data from each of said plurality of encoders and for combining and resequencing the compressed sets into their original sequence as received by said first demultiplexer/multiplexer unit;

an autoblocking unit accepting the sequenced compressed sets of data to create a block of data from a plurality of the compressed sets and to add one data signal identifying a plurality of the blocks of compressed sets;

said format control accepting the blocks of compressed sets of data from said autoblocking unit and transmitting the compressed sets of data to said data control for writing the compressed data into the media under control of said command unit;

said command unit activating said motion control to control said drive and activating said compaction system and said format control to process the write data flow from the channel adaptors through said compaction systems, said format control and said data control to write the compressed data onto the media for storage thereon.

28. A data processing system as defined in claim 27 wherein said compaction system further includes a plurality of decoders and wherein:

said autoblocking unit accepting the blocks of compressed sets of data from the read data unit and removing the added data signals from the compressed sets of data;

said second demultiplexer/multiplexer unit accepting the compressed sets of data from said autoblocking unit and dividing the compressed sets into individual sets according to its identifying signal;

each of said plurality of decoders accepting one compressed set of data in sequential order and processing the set into a decompressed set of data;

said first demultiplexer/multiplexer unit accepting the decompressed sets from each decoder and reassembling the decompressed sets into the original sequence of the sets in the stream of data for transmission to the host processing unit;

said channel adaptors receiving a read command from the central processing unit and said command unit responsive thereto to activate said motion control of said device to transport the media past the transducer to read the compressed data from the media, the compressed data being directed to said data control and said format control for processing and to said autoblocking unit of said compaction system for decompression.

29. A data processing system as defined in claim 28 wherein said plurality of encoders and decoders are each four in number.

30. A compaction system for a data processing system as defined in claim 29 wherein a modulo eight count is set for sequencing the sets of data for compression and decompression by said encoders and decoders, with the four encoders and decoders receiving every fourth set of data and repeating as necessary until all of the sets of data and any remainder of data is compressed and decompressed as needed.

31. A compaction system for a data processing system as defined in claim 30 wherein the sets of data compacted by one encoder of the four encoders is decompacted by one decoder, companion to the one encoder, of the four decoders.

32. A data processing system for compressing data from a central processing unit for storage on a media comprising;

a control unit including channel adaptors for the transmission of data to and from the central processing unit under command control of the central processing unit, a command unit to process the command controls, a compaction system for compressing the data, and a format control; and

a device including a drive for transporting the media past a transducer, a motion control under control of said command unit for controlling said drive, and a data control to activate the transducer to write data onto the media and to retrieve data from the media as the drive transports the media;

said compaction system including;

means for creating sets of data of equal length and a remainder from the stream of data received from the host;

means including a plurality of encoders for compacting the sets of equal length data with each encoder in sequence handling a set of data and processing the set into a compressed set of data;

means for resequencing the compressed sets of data from said compacting means;

means for autoblocking the resequenced compressed sets to add one data signal identifying a block of data formed by said autoblocking means from a plurality of the compressed sets;

said format control accepting the blocks of compressed sets of data from said autoblocking means and transmitting the compressed sets of data to said data control for writing the compressed data onto the media under control of said command unit; and

said command unit activating said motion control to control said drive and activating said compaction system and said format control to process the write data flow from the channel adaptors through said compaction system, said format control and said data control to write the compressed data onto the media for storage thereon.

33. A data processing system as defined in claim 32 wherein said compaction system includes a plurality of decoders and wherein;

said channel adaptors receiving a read command from the control processing unit and said command unit responsive thereto to activate said motion control of said device to transport the media past the transducer to read the compressed data from the media, the compressed data being directed to said data control and said format control for processing and to said autoblocking unit of said compaction system for decompression;

said autoblocking means separates the block of data into the plurality of compressed sets;

said resequencing means separates the plurality of compressed sets of data into individual sets of compressed data;

said plurality of decoders each accepting one individual set of compressed data in sequential order and processing each set into a decompressed individual set of data;

said means for creating sets of data recombining the individual sets of decompressed data into the decompressed stream of data; and

said channel adaptors receiving the decompressed stream of data directing the stream of data to the central processing unit.

34. A data processing system for compressing a stream of data from a central processing unit for storage onto a media comprising:

a control unit including channel adaptors for the transmission of data to and from the central processing unit under command control of the central processing unit, a command unit to process the command controls, a compaction system for compressing the data, and a format control; and

a device including a drive from transporting the media past a transducer, a motion control under control of said command unit for controlling said drive, and a data control to activate the transducer to write data onto the media and to retrieve data from the media as the drive transports the media;

said compaction system including demultiplexing means for creating sets of data of equal length and a remainder from the stream of data received from the host;

four encoding means for encoding the data sets into compressed sets of data, each of said encoding means accepting one set from the sequence of the plurality of sets from said demultiplexing means;

each of said encoding means including two statistic tables, one accessed by its associated encoding means in sequence, such that all eight statistic tables are accessed in sequence, once for every eight set, to create an eight statistic table format for the encoding process;

multiplexing means for combining the compressed sets from said form encoding means to resequence the compressed sets of data into its original sequence before compression;

autoblocking means for accepting the resequenced compressed sets of data for creating a block of data from a plurality of the compressed sets and for adding one data signal identifying a plurality of the blocks of compressed sets;

said format control accepting the blocks of compressed sets of data and transmitting the compressed sets of data to said data control for writing the compressed data onto the media under control of said command unit; and

said command unit activating said motion control to control said drive and activating said compaction system and said format control to process the write data flow from the channel adaptors through said compaction system, said format control and said data control to write the compressed data onto the media for storage thereon.

35. A data processing system as defined in claim 34 wherein said compaction system decompresses the compressed data and further includes;

four decoding means for decoding compressed sets of data into its original set of data each of said decoding means including two statistic tables, one accessed by its associated decoding means in sequence, such that all eight statistic tables are accessed in sequence, once for every eighth set, to permit decoding using the eight statistic table format used for the encoding process;

wherein said autoblocking means unblocks the blocks of compressed data into the compressed sets of data before blocking;

wherein said multiplexing means acts as a demultiplexing means for separation of the compressed sets of data into individual sets for decoding by said decoding means in sequence;

wherein said demultiplexing means acts as a multiplexing means for resequencing the decompressed packets of data from said four decoding means for use by the requesting host processing unit; and

said channel adaptors receiving a read command from the central processing unit and said command unit responsive thereto to activate said motion control of said device to transport the media past the transducer to read the compressed data from the media, the compressed data being directed to said data control and said format control for processing and to said autoblocking unit of said compaction system for decompression.

36. A data processing system for compressing a stream of data from a central processing unit for storage onto a recording media and for retrieval and decompression and transmittal to the central processing unit comprising:

a control unit including channel adaptors for the transmission of data to and from the central processing unit under command control of the central processing unit, a command unit to process the command controls, a compaction system for compressing the data, and a format control; and

a device including a drive for transporting the media past a transducer, a motion control under control of said command unit for controlling said drive, and a data control to activate the transducer to write data onto the media and to retrieve data from the media as the drive transports the media;

said compaction system including demultiplexing means for creating sets of data of equal length and a remainder from the stream of data received from the host;

four encoding means for encoding the data sets into compressed sets of data, each of said encoding means accepting one set from the sequence of the plurality of sets from said demultiplexing means;

each of said encoding means including two statistic tables, one accessed by its associated encoding means in sequence, such that all eight statistic tables are accessed in sequence, once for every eighth set, to create an eight statistic table format for the encoding process;

multiplexing means for combining the compressed sets from said form encoding means to resequence the compressed sets of data into its original sequence before compression;

autoblocking means for accepting the resequenced compressed sets of data for creating a block of data from a plurality of the compressed sets and for adding one data signal identifying a plurality of the blocks of compressed sets;

said format control accepting the blocks of compressed sets of data and transmitting the compressed sets of data to said control for writing the compressed data onto the media under control of said command unit;

said command unit activating said motion control to control said drive and activating said compaction system and said format control to process the write data flow from the channel adaptors through said compaction system, said format control and said data control to write the compressed data onto the media for storage thereon;

four decoding means for decoding compressed sets of data into its original set of data each of said decoding means including two statistic tables, one accessed by its associated decoding means in sequence, such that all eight statistic tables are accessed in sequence, once for every eighth set, to permit decoding using the eight statistic table format used for the encoding process;

wherein said autoblocking means unblocks the blocks of compressed data into the compressed sets of data before blocking;

wherein said multiplexing means acts as a demultiplexing means for separation of the compressed sets of data into individual sets for decoding by said decoding means in sequence;

wherein said demultiplexing means acts as a multiplexing means for resequencing the decompressed packets of data from said form of decoding means for use by the requesting host processing unit; and

said channel adaptors receiving a read command from the central processing unit and said command unit responsive thereto to activate said motion control of said device to transport the media past the transducer to read the compressed data from the media, the compressed data being directed to said data control and said format control for processing and to said autoblocking unit of said compaction system for decompression.

37. A data processing system for compressing data from a central processing unit for storage on a media comprising a control unit including channel adaptors for the transmission of data to and from the central processing unit under command control of the central processing unit, a command unit to process the command controls, a compaction system for compressing the data, and a format control;

said compaction system including a first demultiplexer/multiplexer unit accepting the stream of data and separating the stream of data into sets of data of equal length, except for a remainder;

a plurality of encoders, each accepting one set of data in sequential order from said first demultiplexer/multiplexer unit, with each processing its set into a compressed set of data;

means for adding an identifying signal to each compressed set of data;

a second demultiplexer/multiplexer unit accepting the compressed sets of data from each of said plurality of encoders and for combining and resequencing the compressed sets into their original sequence as received by said first demultiplexer/multiplexer unit;

an autoblocking unit accepting the sequenced compressed sets of data to create a block of data from a plurality of the compressed sets and to add one data signal identifying a plurality of the blocks of compressed sets;

said format control accepting the blocks of compressed sets of data from said autoblocking unit and transmitting the compressed sets of data for writing onto the media under control of said command unit;

said command unit activating said compaction system and said format control to process the write data flow from the channel adaptors through said compaction system and said format control to write the compressed data onto the media for storage thereon.

38. A data processing system as defined in claim 37 wherein said compaction system further includes a plurality of decoders and wherein:

said autoblocking unit accepting the blocks of compressed sets of data from the read data unit and removing the added data signals from the compressed sets of data;

said second demultiplexer/multiplexer unit accepting the compressed sets of data from said autoblocking unit and dividing the compressed sets into individual sets according to its identifying signal;

each of said plurality of decoders accepting one compressed set of data in sequential order and processing the set into a decompressed set of data;

said first demultiplexer/multiplexer unit accepting the decompressed sets from each decoder and reassembling the decompressed sets into the original sequence of the sets in the stream of data for transmission to the host processing unit;

said channel adaptors receiving a read command from the central processing unit and said command unit responsive thereto to retrieve the compressed data from the media, the compressed data being directed to said format control for processing and to said autoblocking unit of said compaction system for decompression.

39. A data processing system for compressing data from a central processing unit for storage on a media comprising a control unit including channel adaptors for the transmission of data to and from the central processing unit under command control of the central processing unit, a command unit to process the command controls, a compaction system for compressing the data, and a format control;

said compaction system including;

means for creating sets of data of equal length and a remainder from the stream of data received from the host;

means including a plurality of encoders for compacting the sets of equal length data with each encoder in sequence handling a set of data and processing the set into a compressed set of data;

means for resequencing the compressed sets of data from said compacting means;

means for autoblocking the resequenced compressed sets to add one data signal identifying a block of data formed by said autoblocking means from a plurality of the compressed sets;

said format control accepting the blocks of compressed sets of data from said autoblocking means and transmitting the compressed sets of data to said data control for writing the compressed data onto the media under control of said command unit; and

said command unit activating said compaction system and said format control to process the write data flow from the channel adaptors through said compaction system and said format control to write the compressed data onto the media for storage thereon.

40. A data processing system as defined in claim 39 wherein said compaction system further includes a plurality of decoders and wherein;

said channel adaptors adapted to receive a read command from the control processing unit and said command unit responsive thereto to retrieve the compressed data from the media, the compressed data being directed to said format control for processing and to said autoblocking unit of said compaction system for decompression;

said autoblocking means separates the block of data into the plurality of compressed sets;

said resequencing means separates the plurality of compressed sets of data into individual sets of compressed data;

said plurality of decoders each accepting one individual set of compressed data in sequential order and processing each set into a decompressed individual set of data;

said means for creating sets of data recombining the individual sets of decompressed data into the stream of data; and

said channel adaptors directing the stream of data to the central processing unit.

41. A data processing system for compressing a stream of data from a central processing unit for storage onto a media comprising a control unit including channel adaptors for the transmission of data to and from the central processing unit under command control of the central processing unit, a command unit to process the command controls, a compaction system for compressing the data, and a format control;

said compaction system including demultiplexing means for creating sets of data of equal length and a remainder from the stream of data received from the host;

four encoding means for encoding the data sets into compressed sets of data, each of said encoding means accepting one set from the sequence of the plurality of sets from said demultiplexing means;

each of said encoding means including two statistic tables, one accessed by its associated encoding means in sequence, such that all eight statistic tables are accessed in sequence, once for every eight set, to create an eight statistic table format for the encoding process;

multiplexing means for combining the compressed sets from said encoding means to resequence the compressed sets of data into its original sequence before compression;

autoblocking means for accepting the resequenced compressed sets of data for creating a block of data from a plurality of the compressed sets and for adding one data signal identifying a plurality of the blocks of compressed sets;

said format control accepting the blocks of compressed sets of data and transmitting the compressed sets of data to said data control for writing the compressed data onto the media under control of said command unit; and

said command unit activating said motion control to control said drive and activating said compaction system and said format control to process the write data flow from the channel adaptors through said compaction system, said format control and said data control to write the compressed data onto the media for storage thereon.

42. A data processing system as defined in claim 41 wherein said compaction system decompresses the compressed data and further includes;

four decoding means for decoding compressed sets of data into its original set of data each of said decoding means including two statistic tables, one accessed by its associated decoding means in sequence, such that all eight statistic tables are accessed in sequence, once for every eighth set, to permit decoding using the eight statistic table format used for the encoding process;

wherein said autoblocking means unblocks the blocks of compressed data into the compressed sets of data before blocking;

wherein said multiplexing means acts as a demultiplexing means for separation of the compressed sets of data into individual sets for decoding by said decoding means in sequence;

wherein said demultiplexing means acts as a multiplexing means for resequencing the decompressed packets of data from said decoding means for use by the requesting host processing unit; and

said channel adaptors receiving a read command from the central processing unit and said command unit and responsive thereto to accept the compressed data from the media, the compressed data being directed to said format control for processing and to said autoblocking unit of said compaction system for decompression.

43. A data processing system for compressing a stream of data from a central processing unit for storage onto a recording media and for retrieval and decompression and transmittal to the central processing unit comprising a control unit including channel adaptors for the transmission of data to and from the central processing unit under command control of the central processing unit, a command unit to process the command controls, a compaction system for compressing the data, and a format control;

said compaction system including demultiplexing means for creating sets of data of equal length and a remainder from the stream of data received from the host;

four encoding means for encoding the data sets into compressed sets of data, each of said encoding means accepting one set from the sequence of the plurality of sets from said demultiplexing means;

each of said encoding means including two statistic tables, one accessed by its associated encoding means in sequence, such that all eight statistic tables are accessed in sequence, once for every eighth set, to create an eight statistic table format for the encoding process;

multiplexing means for combining the compressed sets from said form encoding means to resequence the compressed sets of data into its original sequence before compression;

autoblocking means for accepting the resequenced compressed sets of data for creating a block of data from a plurality of the compressed sets and for adding one data signal identifying a plurality of the blocks of compressed sets;

said format control accepting the blocks of compressed sets of data and transmitting the compressed sets of data for writing onto the media under control of said command unit;

said command unit activating said compaction system and said format control to process the write data flow from the channel adaptors through said compaction system and said format control to write the compressed data onto the media for storage thereon;

four decoding means for decoding compressed sets of data into its original set of data each of said decoding means including two statistic tables, one accessed by its associated decoding means in sequence, such that all eight statistic tables are accessed in sequence, once for every eighth set, to permit decoding using the eight statistic table format used for the encoding process;

wherein said autoblocking means unblocks the blocks of compressed data into the compressed sets of data before blocking;

wherein said multiplexing means acts as a demultiplexing means for separation of the compressed sets of data into individual sets for decoding by said decoding means in sequence;

wherein said demultiplexing means acts as a multiplexing means for resequencing the decompressed packets of data from said decoding means for use by the requesting host processing unit; and

said channel adaptors receiving a read command from the central processing unit and said command unit responsive thereto to retrieve the transducer to read the compressed data from the media, the compressed data being directed to said format control for processing and then to said autoblocking unit of said compaction system for decompression.

44. A data processing unit connected to receive data and commands comprising at least one adaptor for receiving data and commands, a command unit to process the command controls, a compaction system for compressing the data, and a format control;

said compaction system including a compaction unit and an autoblocking unit;

said compaction unit including separating means for separating the stream of data into sets of data of equal length, except for a remainder, and a plurality of encoders, each accepting one set of data in sequential order with each processing its set into a compressed set of data, and further including means for adding an identifying signal to each compressed set of data, and combining means for accepting the compressed sets of data from each cf said plurality of encoders and for combining and resequencing the compressed sets into their original sequence as received by said compaction unit;

said autoblocking unit accepting the sequenced compressed sets of data to create a block of data from a plurality of the compressed sets and to add one data signal identifying a plurality of the blocks of compressed sets;

said format control accepting the blocks of compressed sets of data from said autoblocking unit and for writing the compressed data into said storage means;

said command unit activating said compaction system, said format control and the storage means to process the data flow from the adaptors through said compaction system and said format control to write the blocks of compressed data into the storage means for storage therein.

45. A control unit as defined in claim 44 wherein said compaction unit further includes a plurality of decoders and wherein:

said format control under control of said command unit received the blocks of compressed data from the storage means;

said autoblocking unit deblocking the blocks of compressed sets of data from said format control and removing the added data signals from the compressed sets of data;

said combining means accepting the compressed sets of data from said autoblocking unit and further adapted to divide the compressed sets into individual sets according to its identifying signal;

each of said plurality of decoders accepting one compressed set of data in sequential order an processing the set into a decompressed set of data;

said separating means accepting the decompressed sets from each decoder and adapted for reassembling the decompressed sets into the original sequence of the sets in the stream of data;

said adaptors receiving a retrieve command and said command unit responsive thereto to activate s id storage means to retrieve the stored blocks of compressed data, the blocks of compressed data being directed to said format control for processing.

46. A control unit as defined in claim 45 wherein said plurality of encoders and decoders are each four in number.

47. A control unit as defined in claim 46 wherein a modulo eight count is set for sequencing the sets of data for compression and decompression by said encoders and decoders, with the four encoders and decoders receiving every fourth set of data and repeating as necessary until all of the sets of data and any remainder of data is compressed and decompressed as needed.

48. A control unit as defined in claim 45 wherein the sets of data decompacted by one encoder of the four encoders is decompacted by one decoder, companion to the one encoder, of the four decoders.

49. A control unit as defined in claim 45 further including means controlled by said command unit for bypassing said compaction unit when compaction is not required on the data received by said adaptors.

50. A data processing system for compressing data for storage on a media comprising:

at least one adaptor for receiving data and commands, a command unit to process the commands, a compaction system for compressing the data, and a format control; and

a device including a drive for transporting the media past a transducer, a motion control under control of said command unit for controlling said drive, and a data control to activate the transducer to write data onto the media and to retrieve data from the media as the drive transports the media;

said compaction system including a compaction unit and an autoblocking unit;

said compaction unit including separating means for separating the stream of data into sets of data of equal length, except for a remainder, and a plurality of encoders, each accepting one set of data in sequential order with each processing its set into a compressed set of data, and further including means for adding an identifying signal to each compressed set of data, and combining means for accepting the compressed sets of data from each of aid plurality of encoders and for combining and resequencing the compressed sets into their original sequence as received by said compaction unit;

said autoblocking unit accepting the sequenced compressed sets of data to create a block of data from a plurality of the compressed sets and to add one data signal identifying a plurality of the blocks of compressed sets;

said format control accepting the blocks of compressed sets of data from said autoblocking unit and transmitting the compressed sets of data to said data control for writing the compressed data onto the media under control of said command unit;

said command unit activating said motion control to control said drive and activating said compaction system and said format control to process the write data flow from the channel adaptors through said compaction system, said format control and said data control to write the blocks of compressed data onto the media for storage thereon.

51. A data processing system as defined in claim 50 wherein said compaction unit further includes a plurality of decoders and wherein:

said autoblocking unit deblocking the blocks of compressed sets of data received from the read data unit and removing the added data signals from the blocks of compressed sets of data;

said combining means accepting the compressed sets of data from said autoblocking unit and further adapted to divide the compressed sets into individual sets according to its identifying signal;

each of said plurality of decoders accepting one compressed set of data in sequential order and processing the set into a decompressed set of data;

said separating means adapted for accepting the decompressed sets from each decoder and reassembling the decompressed sets into the original sequence of the sets in the stream of data for transmission to said adaptors;

said adaptor receiving a read command and said command unit responsive thereto to activate said motion control of said device to transport the media past the transducer to read the compressed data from the media, the compressed data being directed to said data control and said format control for processing and to said autoblocking unit of said compaction system for decompression.

52. A data processing system as defined in claim 50 wherein said media is a magnetic tape media.

53. A data processing system as defined in claim 52 wherein said magnetic tape media is stored in a cartridge and said drive is adapted to remove the media from the cartridge past said transducer under control of said motion control, and includes a motor drive to rotate the cartridge reel and the take-up reel, with the motor drive being controlled by said motion control.