JPH01282709A - Magnetic tape device - Google Patents

Abstract

PURPOSE:To avoid a medium error in a short time by an automatic retry processing of once by detecting a medium error position and erasing the medium error position. CONSTITUTION:A data counter 4 counts demodulation data of a demodulating circuit 3 until a medium error signal of the demodulating circuit 3 is outputted by a write operation under the control of a control circuit 5B, and outputs data counting information extending from an (a) point of a magnetic tape medium to a (p) point of a medium error position to the control circuit 5B. Subsequently, due to a space reverse operation of an automatic retry processing, the control circuit 5B controls a driving circuit 7 and the magnetic tape medium is run in reverse from an (aa) point to the (a) point. Due to the subsequent erasing operation, the control circuit 5B runs the magnetic tape medium in the advance direction, and controls an erasing circuit 1 so as to erase up to a position which has added a prescribed position to the medium error position. As a result, as for the magnetic tape medium, the (a) point through an (r) point containing the (p) point of the medium error position are erased. In such a way, a medium error can be avoided at a time.

Description

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

(Prior Art) Conventionally, this type of magnetic tape device has a configuration as shown in the block diagram of FIG. 2, and its recording state is as shown in FIG. 4.

To explain this conventional example according to the drawing, the magnetic tape control device 9 sends write data by a write command in order to write data to the magnetic tape device 8A.

The magnetic tape device 8A 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 5A and also outputs write data to the data buffer 1o. 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 traveling direction. Also, at the beginning of the write operation, the write error flag in the internal register of the control circuit 5A is reset. Data already written on the magnetic tape medium is erased by the erasing circuit 1 under the control of the control circuit 5A, and data from the data buffer 10 is written onto the magnetic tape medium by the writing circuit 2 under the control of the control circuit 5A. 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, and the analog data is shaped into pulse data under the control of the control circuit 5A, and the data is demodulated. . 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 assumed that drop focus is present 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. As a result, the magnetic tape medium includes two medium error positions, and data is written from point a to point aa.

The control circuit 5A performs the following automatic retry process to avoid medium errors when the write error flag of the internal register is set.For space reverse operation, the control circuit 5A controls the drive circuit 7 to reel. The motor and capstan motor are driven to run the magnetic tape medium in the opposite 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. In this way, the tape medium 6 is run backwards from point aa to point a. Control circuit 5 for the subsequent erase operation.
A controls the drive circuit 7, drives the rotary motor and the capstan motor to run the tape medium in the traveling direction, and controls the erasing circuit 1 to erase a predetermined distance P. With this, the magnetic tape medium is a certain distance from point a! The data up to point b, which is the sum of
The same data in which a write error occurred is written to the magnetic tape medium using the same write operation as described above. As a result, data is written to the magnetic tape medium from point b to point bb, but the data is written at two points at the medium error position. The write error flag of the internal register of the control circuit 5A is set again.

As a result of the above automatic retry process, the data previously written on the magnetic tape medium is shifted by the erased distance in the advancing direction. Since the write error flag in the internal register of the control circuit 5A is set, the automatic retry process is repeated and the data is shifted and written to a position where no medium error is detected.This causes the magnetic tape medium to detect a medium error. Data is written from n points that do not include position 1.

(Intelligence to be Solved by the Invention 1!fl) The conventional magnetic tape device described above can erase only a predetermined short distance of written data in one automatic retry process.
Depending on the position of the media error, the retry process must be repeated many times to avoid the media error, and the automatic retry process takes a lot of time.

(Means for Solving the Problems) A magnetic tape device of the present invention includes a data buffer for storing data to be written on a magnetic tape medium, a write circuit for writing data on the magnetic tape medium, and a write circuit for storing data to be written on the magnetic tape medium. a demodulation circuit that performs demodulation and detects the occurrence of drop bits due to medium errors; a control circuit that controls erasing of a certain distance in an erase operation; an erase circuit that performs erasing under the control of the control circuit; A magnetic tape Viin comprising at least a drive circuit that drives a reel motor and a capstan motor under control, a data counter that counts demodulated data of the demodulation circuit until the demodulation circuit detects a medium error, and automatic retry processing. In the erase operation following the space reverse operation, the control circuit controls erasing up to a position where a certain distance is added to the position of the medium error based on the information of the data counter.

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

FIG. 1 is a block diagram of one embodiment of the present invention, and FIG. 3 is a recording state diagram of the magnetic tape device of the present invention.

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 also outputs write data to the data buffer 10. 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 traveling direction. Also, 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. The data already written on the magnetic tape medium is erased by the erasing circuit 1 under the control of the control circuit 5B, while the data from the data buffer 10 is written onto the magnetic tape medium by the writing circuit 2 under the control of the control circuit 5B. . Immediately after, change the write state to f+1!4'Q
In order to do this, the data written on the magnetic tape medium is read out by the demodulation circuit 3, the analog data is shaped into pulse data by the control 0 of the control circuit 5B, and the data is demodulated and sent to the data counter 4. Output.

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 outputs a medium error signal to the control circuit 5B. Ru. 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. data counter 4
is the demodulation circuit 3 in the write operation under the control of the control circuit 5B.
The demodulated data of the demodulation circuit 3 is counted until a medium error signal of 1 is output, and the data count information from point a of the magnetic tape medium to the medium error point iZP is outputted to the control circuit 5B. As a result, the magnetic tape medium includes two medium error positions, and data is written from point a to point aa.

The control circuit 5B performs the following automatic retry process to avoid medium errors when the write error flag of the internal register is set.For space reverse operation, the control circuit 5B controls the drive circuit 7 to reel. The motor and capstan motor are driven to run the magnetic tape medium in the opposite direction. The demodulation circuit 3 detects the start of data written on the magnetic tape medium and outputs it to the control circuit 5B. The control circuit 5B controls the drive circuit 7 to stop driving the motor. In this way, the magnetic tape medium is run backwards from point aa to point a. Control circuit 5B for subsequent erase operation
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 erase data up to a position where a certain distance is added to the medium error position according to the count information of the data counter 4. Erase circuit 1
control. With this, the magnetic tape medium includes two medium error positions, and the area from point a to point r is erased.

In the subsequent write operation, the same data that is stored in the data buffer 10 and in which the write error occurred is written to the 6n tape medium in the same write operation as described above. In this way, data is written on the magnetic tape medium from point r to point rr, which does not include the medium error point Up.

With the above automatic retry process, it is possible to avoid medium errors at least once.

(Effects of the Invention) As explained above, the present invention detects the media error position and erases the media including the error position, thereby avoiding the media error with one automatic retry process. There is an effect that can be avoided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a magnetic tape device of the present invention, FIG. 2 is a block diagram of a conventional magnetic tape device, FIG. 3 is a recording state diagram of the magnetic tape device of the present invention, and FIG. 4 is a conventional magnetic tape device. FIG. 3 is a recording state diagram of the device. l... 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, a, b, aa, n, r... Data writing start point, 2
...Erasure distance, p...Medium error position, bb, nn
, rr... Data writing end point.

Claims (1)

[Claims] a data buffer that stores data to be written to a magnetic tape medium; a write circuit that writes data to the magnetic tape medium; a demodulation circuit that demodulates data on the magnetic tape medium and detects the occurrence of a drop bit due to a medium error; A magnetic field comprising at least a control circuit that controls erasing of a certain distance in an erase operation, an erasing circuit that performs erasing under the control of the control circuit, and a drive circuit that drives a reel motor and a capstan motor under the control of the control circuit. The tape device includes 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 the demodulated data of the demodulation circuit until the demodulation circuit detects a medium error. 1. A magnetic tape device comprising: a control circuit that controls erasing up to a position plus a certain distance.