JPH02260204A - Magnetic tape device - Google Patents

Abstract

PURPOSE:To prevent the control of a magnetic tape control device from being complexed by providing the magnetic tape device with a data buffer for storing data to be written in a magnetic tape medium to rewrite data for retry processing by using data read out from the data buffer. CONSTITUTION:The magnetic tape device is provided with the data buffer 10 for storing data to be written in the magnetic tape medium to rewrite data for retry processing by using data read out from the data buffer 10. Namely, a control circuit 5B travels the magnetic tape medium reversely to execute space reversing operation and then erases data up to a position obtained by adding a fixed distance to a medium error position based upon the counting information of a data counter 4 to execute the succeeding erasing operation. In the succeeding writing operation, the circuit 5B writes the same data generating a writing error which stored in the data buffer 10 are written in the magnetic tape medium. Since the medium error can be processed by one automatic retry processing, the control of the magnetic tape device can be simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a magnetic tape device used as an external storage device of an information processing device, and particularly to a magnetic tape device that performs efficient automatic retry processing.

(Prior Art) Conventionally, this type of magnetic tape device has a configuration as shown in FIG.

Write data is sent from the magnetic tape control device 9 to the magnetic tape device 8A in response to a write command.

In the magnetic tape device 8A, the interface circuit 6 receives this write command from the magnetic tape control device 9 and starts a write operation. Interface circuit #I6 outputs the received command to control circuit 5A. Control port F#5A controls the drive circuit 7 to drive the reel motor and capstan motor to run the magnetic tape medium in the traveling direction. Further, at the beginning of the write operation, the write error flag of the internal register of the control circuit 5A and the data counter 4 are reset.

The data already written on the magnetic tape medium is erased at the erase port F#Il under the control of the control circuit 5A, and the write data received by the interface circuit 6 is transferred to the magnetic tape by the write circuit 2 under the control of the control circuit 5A. Number 4 to check the write status immediately after writing to the medium
A demodulation circuit 3 converts the data written to the magnetic tape medium into
The analog data is read out and shaped into pulse data under the control of the control circuit 5A, and the data is demodulated and output to the data counter 4. Furthermore, the demodulation circuit 3 determines whether the level of the data read signal is above a certain level, and when the level of the data read signal is below the certain level, it is assumed that the bit is a drop bit and outputs a medium error signal to the control circuit 5A. .

When the control circuit 5A receives the medium error signal from the demodulation circuit 3, it sets a write error flag in an internal register. The data counter 4 counts the demodulated data of the demodulating circuit 3 until the medium error signal of the demodulating circuit 3 is output in a write operation under the control of the control circuit 5A, and sends the data to the magnetic field of the control circuit 5A as shown in FIG. Outputs data count information from point a, where data writing begins on the tape medium, to point 9, the medium error position. The magnetic tape medium is now at medium error position 2.
data is written from point A to point aa, which is the end of data writing.

The control circuit 5A reports the write error to the magnetic tape control device 9 via the interface circuit 6 if the write error flag of the internal register is set.

When the magnetic tape control device 9 receives a write error report, it performs the following retry process to avoid the write error.

The magnetic tape control device 9 sends a space reverse command to the magnetic tape device 8A. For space reverse operation, the control circuit 5A controls the drive circuit 7 to drive the reel motor and capstan motor to run the magnetic tape medium in the reverse direction. The demodulation circuit 3 detects the start of data written on the magnetic tape medium and outputs it to the control circuit 5A.

The control circuit 5A controls the drive circuit 7 to stop driving the motor. As a result, the magnetic tape medium is moved backwards from point aa to point a.

The magnetic tape control device 9 sends an erase command to the magnetic tape device 8A. Control circuit 5A for subsequent erase operation
controls the drive circuit 7 to drive the reel motor and capstan motor to run the magnetic tag IJX body in the traveling direction, and if the write error flag of the internal register is set, the IJX is
The erasing circuit 1 is controlled so as to erase up to the position of the A-body error plus a certain distance. With this, the magnetic tape medium includes 9 medium error positions, the data writing start point, a
The area from point to point r is erased.

The magnetic chip 1 control device 9 sends the same data in which a write error occurred in a write command to the magnetic tape device 8A. The same data in which a write error occurred in the subsequent write operation is written to the magnetic tape medium in the same write operation as described above. As a result, data is written on the magnetic tape medium from point r, which does not include the two medium error positions, to point rr, which is the end point of data writing.

(Problems to be Solved by the Invention) The conventional magnetic tape device described above executes retry processing based on instructions from the magnetic tape control device, so it has the disadvantage that control from the magnetic tape control device is complicated. be.

(Means for Solving the Problem) A magnetic tape device according to the present invention includes a write circuit that writes data to a magnetic tape medium, and a write circuit that demodulates the data written to the magnetic tape medium and prevents the occurrence of drop bits due to medium errors. a demodulation circuit that detects a medium error; a data counter that counts demodulated data of the demodulation circuit until the demodulation circuit detects a medium error; and a data counter that counts demodulated data of the demodulation circuit until the demodulation circuit detects a medium error. A magnetic tape device comprising: a control circuit for controlling erasing and rewriting of data up to a position plus a certain distance from the position of ah; and an erasing circuit for erasing under the control of the control circuit;
A data buffer for storing data to be written is provided, and data read from the data buffer is used to rewrite data in the retry process.

(Example) Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a recording state diagram.

The magnetic tape control device 9 sends write data using a write command in order to write data to the magnetic tape device 8B. The magnetic tape device 8B receives a command from the magnetic tape control device 9 through the interface circuit 6 and starts a write operation. The interface circuit 6 outputs the received command to the control circuit 5B and outputs write data to the data buffer 10. The control circuit 5B controls the drive circuit 7 to drive the reel motor and the capstan motor to run the magnetic tape medium in the traveling direction.

Furthermore, at the beginning of the write operation, the write error flag of the internal register of the control circuit 5B and the data counter 4 are reset. Data already written on the magnetic tape medium is erased in the erasing circuit 1 under the control of the control circuit 5B, and data from the data buffer 10 is written on the magnetic tape medium in the write cycle fit32 under the control of the control circuit 5B.

Immediately after, in order to confirm the write state, the data written to the magnetic tape medium is read out by the demodulation circuit 3, the analog data is shaped into pulse data under the control of the control circuit 5B, and the data is demodulated. Output to data counter 4.

Further, the demodulation circuit 3 determines whether the level of the data read signal is above a certain level, and when the level of the data read signal is below a certain level, it is regarded as a drop bit and the medium error signal is sent to the control circuit 5B. Output to. When the control circuit 5B receives the medium error signal from the demodulation circuit 3, it sets a write error flag in an internal register. The data counter 4 counts the IM and modulation data of the demodulation circuit 3 until the medium error signal of the demodulation circuit 3 is output in the write operation under the control of the control circuit [15B].
Data count information from point a of the magnetic tape medium to point ρ, the medium error position, is output to B. With this, the magnetic tape medium includes the medium error position point p, and data is written from point a to point aa.

When the write error flag in the internal register is set, the control circuit 1785B performs the following automatic retry process to avoid medium errors.

For space reverse operation, the control circuit 5B controls the drive circuit 7 to drive the reel motor and capstan motor to run the magnetic tape medium in the reverse direction. The demodulation circuit 3 detects the start of writing data written on the magnetic tape medium and outputs it to the control circuit 5B. Control circuit 5B
controls the drive circuit 7 to stop driving the motor.

As a result, the magnetic tape medium is moved backward from point aa to a and a.

In the subsequent erase operation, the control circuit 1i5B controls the drive circuit 7 to drive the reel motor and the capstan motor to run the magnetic tape medium in the advancing direction, and keep it at the medium error position according to the count information of the data counter 4. The erasing circuit 1 is controlled to erase up to the position where the distance is added. As a result, the magnetic tape medium includes the medium error position point P and is erased from point a to point r.

In the subsequent write operation, the same data that is stored in the data buffer 1o and in which the write error occurred is written to the magnetic tape medium in the same write operation as described above. As a result, data is written on the magnetic tape body O from point r to point rr, which does not include the medium error position point p.

Through the automatic retry process described above, the magnetic tape device automatically avoids a medium error with a single RIE 1 command from the magnetic tape control device.

(Effects of the Invention) As described above, the present invention has the advantage that the magnetic tape device can be easily controlled because medium errors can be avoided by a single automatic retry process.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a magnetic tape device according to the present invention, FIG. 2 is a diagram for explaining the recording state of a magnetic tape device in the conventional case and this embodiment, and FIG. 3 is a block diagram showing a conventional magnetic tape device. FIG. 2 is a block diagram of a tape device. DESCRIPTION OF SYMBOLS 1... Erase circuit, 2... Write circuit, 3... Demodulation circuit, 4... Data counter, 5A, 5B... Control circuit, 6... Interface circuit, 7... Drive circuit , 8A, 8B...Magnetic tape device, 9...Magnetic tape control device, 10...Data buffer.

Claims (1)

[Claims] a write circuit that writes data to a magnetic tape medium; a demodulation circuit that demodulates the data written to the magnetic tape medium and detects the occurrence of a drop bit due to a medium error; and a demodulation circuit that demodulates the data until the demodulation circuit detects a medium error. A data counter counts the demodulated data of the circuit, and in the erase operation following the space reverse operation of the retry process, the information in the data counter is used to erase and rewrite data up to a position where a certain distance is added to the position of the medium error. A magnetic tape device comprising a control circuit for controlling and an erasing circuit for erasing under the control of the control circuit, further comprising a data buffer for storing data to be written on the magnetic tape medium, and using data read from the data buffer. A magnetic tape device characterized in that data is rewritten in the retry process.