Error correcting system of a magnetic tape unit

Claim 2

An error processing system for use with reversible transport means for moving selectively a magnetic tape in a first direction and in a second direction opposite to the first direction, the transport means including read-write means for recording the data in the form of bytes each including a plurality of bits on a corresponding plurality of tracks of the magnetic tape, and for reading data from the magnetic tape to provide signals indicative of the bits recorded thereon, the information bytes being recorded in the form of a data block and a tape mark block with an interblock gap disposed therebetween, said error processing system comprising: a. an instruction register responsive to an instruction signal derived from an information processing unit for generating a write initiate signal; b. tape drive control means comprising memory means operative in a first state in response to the write initiate signal to effect movement of the magnetic tape in the first direction and in a second state to effect movement of the magnetic tape in the second direction, and counting circuits coupled to said instruction register for providing a timing pulse at a selected interval of time after the generation of the write initiate signal; c. write control means responsive to the delayed timing pulse for providing a first write tape mark signal whereby the readwrite means records a first tape mark block at a first position on a magnetic tape, while said tape drive control means is disposed in its first state to effect movement of the magnetic tape in the first direction; d. error check means responsive to the signals read by the readwrite means corresponding to the recorded first tape mark block, for providing an error signal upon the occurrence of a tape mark error condition; and e. error correcting means responsive to the error signal for first disposing said tape drive control means in a second state whereby the magnetic tape is moved in the second direction while erasing this portion of the magnetic tape, and for then initiating the operation of said control means to provide a second write tape mark signal after a predetermined interval whereby a second tape mark block is written on a second position of the magnetic tape displaced from the first position.

Claim 3

An error processing system as claimed in claim 1 wherein said write control means is responsive to the delayed timing pulse for applying to the read-write means the write tape mark block signal whereby a tape mark block comprising a first tape mark byte and a second, redundant tape mark byte are recorded upon the magnetic tape.

Claim 4

An error processing system as claimed in claim 2, wherein said error check means includes a register for receiving and storing from the read-write means, read data signals corresponding to the recorded tape mark block.

Claim 5

An error processing system for use with reversible transport means for moving selectively a magnetic tape in the first direction and in a second direction opposite to the first direction, the transport means including read-write means for recording the data in the form of bytes each including a plurality of bits on a corresponding plurality of tracks of the magnetic tape, and for reading from the magnetic tape to provide signals indicative of the bits recorded thereon, the information bytes being recorded in the form of a data block and a tape mark block with an interblock gap disposed therebetween, the tape mark block comprising first and second tape mark bytes, each comprising the same selected bits, said error processing system comprising: a. tape drive control means selectively disposal on a first state to operate the transport means to drive the magnetic tape in the first direction and in a second state to operate the transport means to drive the magnetic tape in the second direction; b. write control means for providing a first write tape mark block signal whereby the read-write means records a first tape mark block at a first position on the magnetic tape, while said tape drive control means is disposed in its first state to effect movement of the magnetic tape in the first direction; c. error check means responsive to the signals read by the read-write means corresponding to the recorded first tape mark block, for providing an error signal upon the occurrence of a tape mark error conditIon, and including interblock gap detection means responsive to the signals read by the read-write means for providing an interblock gap signal indicative of the absence of read data signals for a predetermined length of time, an error detection circuit for detecting the presence of each selected bit of the first and second bytes and for providing the aforementioned error signals in the absence of at least one bit thereof, and an AND gate means responsive to the error signal and to the interblock gap signal for providing a coincidence signal; and d. error correcting means responsive to the error signal for first disposing said tape drive control means in its second state whereby the magnetic tape is moved in the second direction while erasing this portion of the magnetic tape, and for then initiating the operation of said write control means to provide a second write tape mark signal after a predetermined interval whereby a second tape mark block is written on a second position of the magnetic tape displaced from the first position.

Claim 6

An error processing system for use with reversible transport means for moving selectively a magnetic tape in the first direction and in a second direction opposite to the first direction, the transport means including read-write means for recording the data in the form of bytes each including a plurality of bits on a corresponding plurality of tracks of the magnetic tape, and for reading from the magnetic tape to provide signals indicative of the bits recorded thereon, the information bytes being recorded in the form of a data block and a tape mark block with an interblock gap disposed therebetween, the tape mark block comprising first and second tape mark bytes, each comprising the same selected bits, said error processing system comprising: a. tape drive control means selectively disposal on a first state to operate the transport means to drive the magnetic tape in the first direction and in a second state to operate the transport means to drive the magnetic tape in the second direction; b. write control means for providing a first write tape mark block signal whereby the read-write means records a first tape mark block at a first position on the magnetic tape, while said tape drive control means is disposed in its first state to effect movement of the magnetic tape in the first direction; c. error check means responsive to the signals read by the read-write means corresponding to the recorded first tape mark block, for providing an error signal upon the occurrence of a tape mark error conditIon, and including interblock gap detection means responsive to the signals read by the read-write means for providing an interblock gap signal indicative of the absence of read data signals for a predetermined length of time, an error detection circuit for detecting the presence of each selected bit of the first and second bytes and for providing the aforementioned error signals in the absence of at least one bit thereof, and an AND gate means responsive to the error signal and to the interblock gap signal for providing a coincidence signal; and d. error correcting means responsive to the error signal for first disposing said tape drive control means in its second state whereby the magnetic tape is moved in the second direction while erasing this portion of the magnetic tape, and for then initiating the operation of said write control means to provide a second write tape mark signal after a predetermined interval whereby a second tape mark block is written on a second position of the magnetic tape displaced from the first position.

Claim 7

An error processing system for use with reversible transport mens for moving selectively a magnetic tape in a first direction and in a second direction opposite to the first direction, the transport means including read-write means for recording the data in the form of bytes each including a plurality of bits on a corresponding plurality of tracks of the magnetic tape, and for reading data from the magnetic tape to provide signals indicative of the bits recorded thereon, the information bytes being recorded in the form of a data block and a tape mark block with interblock gap disposed therebetween, said error processing system comprising: a. tape drive control means selectively disposable in a first state to operate the transport means to drive the magnetic tape in the first direction and in a second state to operate the transport means to drive a magnetic tape in the second direction; b. write control means for providing a first write tape mark block signal whereby the read-write means records a first tape mark block at a first position on a magnetic tape, while said tape drive control means is disposed in its first state to effect movement of the magnetic tape in the first direction; c. error check means responsive to the signals read by the read-write means corresponding to the recorded first tape mark block, for providing an error signal upon the occurrence of a tape mark error condition; d. error correcting means responsive to the error signal for first disposing said tape drive control means in its second state whereby the magnetic tape is moved in a second direction while erasing this portion of the magnetic tape, and then for initiating the operation of said write control means to provide a second write tape mark signal after a predetermined interval whereby a second tape mark block is written on a second position of the magnetic tape displayed from the first position, said error correcting means providing a write initiate signal after the first mentioned predetermined interval to said tape drive control means thereby disposing said tape drive control means in its first state and effecting the movement of a magnetic tape in the first direction; and e. a counting circuit responsive to the write initiate signal to energize said write control means, whereby a second tape mark block is written upon the magnetic tape a second interval after the initiation of the movement of the magnetic tape in the first direction, the second interval being determined by said counting circuit.

Claim 8

An error processing system for use with reversible transport mens for moving selectively a magnetic tape in a first direction and in a second direction opposite to the first direction, the transport means including read-write means for recording the data in the form of bytes each including a plurality of bits on a corresponding plurality of tracks of the magnetic tape, and for reading data from the magnetic tape to provide signals indicative of the bits recorded thereon, the information bytes being recorded in the form of a data block and a tape mark block with interblock gap disposed therebetween, said error processing system comprising: a. tape drive control means selectively disposable in a first state to operate the transport means to drive the magnetic tape in the first direction and in a second state to operate the transport means to drive a magnetic tape in the second direction; b. write control means for providing a first write tape mark block signal whereby the read-write means records a first tape mark block at a first position on a magnetic tape, while said tape drive control means is disposed in its first state to effect movement of the magnetic tape in the first direction; c. error check means responsive to the signals read by the read-write means corresponding to the recorded first tape mark block, for providing an error signal upon the occurrence of a tape mark error condition; d. error correcting means responsive to the error signal for first disposing said tape drive control means in its second state whereby the magnetic tape is moved in a second direction while erasing this portion of the magnetic tape, and then for initiating the operation of said write control means to provide a second write tape mark signal after a predetermined interval whereby a second tape mark block is written on a second position of the magnetic tape displayed from the first position, said error correcting means providing a write initiate signal after the first mentioned predetermined interval to said tape drive control means thereby disposing said tape drive control means in its first state and effecting the movement of a magnetic tape in the first direction; and e. a counting circuit responsive to the write initiate signal to energize said write control means, whereby a second tape mark block is written upon the magnetic tape a second interval after the initiation of the movement of the magnetic tape in the first direction, the second interval being determined by said counting circuit.

Claim 9

An error processing system for use with reversible transport means for moving selectively a magnetic tape in a first direction and in a second direction opposite to the first direction, the transport means including read-write means for recording the data in the form of bytes each including a plurality of bits on a corresponding plurality of tracks of the magnetic tape, and for reading data from the magnetic tape to provide sigNals indicative of the bits recorded thereon, the information bytes being recorded in the form of a data block and a tape mark block with an interblock gap disposed there-between, said error processing system comprising: a. tape drive control means selectively disposable in a first state to operate the transport means to drive the magnetic tape in the first direction and in a second state to operate the transport means to drive the magnetic tape in the second direction; b. write control means for providing a first write tape mark block signal whereby the read-write means records a first tape mark block at a first position on the magnetic tape, while said tape drive control means is disposed in its second state to effect movement of the magnetic tape in the first direction; c. error check means including a plurality of memory means coupled to receive the read data signals corresponding to a recorded tape mark block having first and second bytes each having selected bits therein, each of said memory means disposable in a first state in response to the receipt of the selected bits of the first byte and disposable in a second state in response to receipt thereafter of the selected bits in the second byte, and first coincidence means responsive to the receipt of the selected bits of the first and second bytes to provide a coincidence signal, said error check means providing an error signal in response to the occurrence of both the coincidence signal and the disposition of said plurality of said memory means to their second states; and d. error correcting means responsive to the error signal for first disposing said tape drive control means in its second state whereby the magnetic tape is moved in the second direction while erasing this portion of the magnetic tape, and for then initiating the operation of said write control means to provide a second write tape mark signal after a predetermined interval whereby a second tape mark block is written on a second position of the magnetic tape displaced from the first position.

Claim 10

An error processing system for use with reversible transport means for moving selectively a magnetic tape in a first direction and in a second direction opposite to the first direction, the transport means including read-write means for recording the data in the form of bytes each including a plurality of bits on a corresponding plurality of tracks of the magnetic tape, and for reading data from the magnetic tape to provide sigNals indicative of the bits recorded thereon, the information bytes being recorded in the form of a data block and a tape mark block with an interblock gap disposed there-between, said error processing system comprising: a. tape drive control means selectively disposable in a first state to operate the transport means to drive the magnetic tape in the first direction and in a second state to operate the transport means to drive the magnetic tape in the second direction; b. write control means for providing a first write tape mark block signal whereby the read-write means records a first tape mark block at a first position on the magnetic tape, while said tape drive control means is disposed in its second state to effect movement of the magnetic tape in the first direction; c. error check means including a plurality of memory means coupled to receive the read data signals corresponding to a recorded tape mark block having first and second bytes each having selected bits therein, each of said memory means disposable in a first state in response to the receipt of the selected bits of the first byte and disposable in a second state in response to receipt thereafter of the selected bits in the second byte, and first coincidence means responsive to the receipt of the selected bits of the first and second bytes to provide a coincidence signal, said error check means providing an error signal in response to the occurrence of both the coincidence signal and the disposition of said plurality of said memory means to their second states; and d. error correcting means responsive to the error signal for first disposing said tape drive control means in its second state whereby the magnetic tape is moved in the second direction while erasing this portion of the magnetic tape, and for then initiating the operation of said write control means to provide a second write tape mark signal after a predetermined interval whereby a second tape mark block is written on a second position of the magnetic tape displaced from the first position.