JPH11296931A - Tape positioning method in magnetic tape device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To start a write-in processing without shifting a write-in position by positioning a tape start position regardless of the operation of forward/ backward direction by performing positional correction in the case of the backward running after a tape is stopped with positioning signals different in the forward direction and the backward direction of tape running. SOLUTION: When a read-in circuit 21 ends to block read in the tape 4 to detect an interblock gap IBG, a control part 8 checks the operational direction of the tape 4, and commands the read-in circuit 21 to send out the positioning signal in the middle of the IBG when it is the forward direction. When it is the backward direction, the control part 8 commands to send out the positioning signal in the terminal end of the IBG, and stops the tape operation by a drive circuit 7 according to beforehand programed conditions, and adds the half of the standard value of the IBG to correct the position of the tape 4. Thus, the positioning to the middle position of the IBG is performed regardless of the forward directional and backward directional operation, and the write-in of the data from an erroneous position is prevented, and the matter that the required data are erased is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic tape positioning control, and more particularly, to a tape positioning method which can be started without shifting the writing position regardless of the order of the previous operation.

[0002]

2. Description of the Related Art A description will be given of a tape positioning method in a magnetic tape device prior to the present invention. The configuration is the same as that shown in FIG. 1 and operates as follows.

That is, the operation direction of the tape 4 is a forward direction,
Regardless of the reverse direction, when reading of a block is completed and an inter-block gap (hereinafter referred to as IBG) is detected, if the block is determined to be normal by the control unit 8, an intermediate IBG (IBG The positioning signal is transmitted at a value (half the standard value) and the tape 4 is stopped when necessary.
In the restart operation of the tape 4, the positioning of the tape 4 is performed with respect to the position of the positioning signal transmitted last, and the read / write processing is continuously performed.

However, prior arts of the present invention include:
There were the following problems.

[0005] The first problem is that when the tape 4 is stopped by performing positioning from the reverse direction and writing processing is performed on the tape 4, the gap length between blocks may exceed the maximum value of the standard value. That's what it means. It is assumed that the reason is that the recorded inter-block gap length is 3 mm, which is the full standard value, in the normal IBG tape 4 having the standard value of 2 mm. At the time of writing, if the magnetic tape device writes an IBG of 1.2 mm from the restart position of the tape 4, a positioning signal is sent from the reverse direction to a position of the 3mm IBG at half the normal specification value of 2mm. Then, a positioning signal is output at a position of 2 mm of the IBG when viewed from the medium leading end side. Therefore, if writing is performed from here, it will be 2 mm + 1.2 mm, exceeding the standard value of 3 mm at the maximum.

The second problem is that when the tape 4 is stopped by performing positioning from the reverse direction and writing processing is performed on the tape 4, the gap length between blocks may fall below the minimum value of the standard value. That's what it means. It is assumed that the reason is that the recorded inter-block gap length is 1.6 mm, which is the full standard value, in the IBG tape 4 having the normal standard value of 2 mm. If the magnetic tape device writes an IBG of 0.9 mm from the restart position of the tape 4 at the time of writing, the IBG of 1.6 mm is positioned at half the position of the normal specification value of 2 mm from the reverse direction. Is transmitted, a positioning signal is generated at a position of 0.6 mm of the IBG when viewed from the medium leading end side. Therefore, when writing is performed from here, 0.6 mm + 0.9 mm
This is because it is less than the minimum value of 1.6 mm. Examples of related gazettes in such a field include the following. SUMMARY OF THE INVENTION According to the present invention, in order to position a plurality of blocks, a plurality of commands must be issued. In order to position a plurality of blocks, only one command is required. is there. In other words, the present invention aims at shortening the positioning processing time, and is completely different from the present invention aiming at eliminating the misalignment of the tape. This example is an invention for preventing necessary data from being accidentally erased at the time of overwriting, and has an object close to the object of the present invention.

However, in this embodiment, the write timing to the tape is generated based on the information of the tape read by the read head at the time of writing the data. On the other hand, in the present invention, the calculation of the write start position always uses the gap between the blocks. There is a difference that measurement is performed from the media start side.

[0008]

In the conventional tape positioning method in the magnetic tape device, there has been a problem that the writing position is shifted in the writing process after the tape is positioned from the opposite direction.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method capable of starting a writing process without shifting a writing position in a writing process after positioning a tape in a forward direction and a reverse direction.

[0010]

A tape positioning method in a magnetic tape device according to the present invention is a tape positioning method in a magnetic tape device in which a tape can be positioned by running in a reverse direction. , Normal termination and forward / reverse direction.
In the middle of the IBG, in the reverse direction, a positioning signal requesting step 201 for requesting a positioning signal at the end of the IBG, a recording step 202 for recording a positioning signal transmission position under the condition of completion of the positioning signal transmission, There is a tape stop processing stage 203 for performing a tape stop process based on condition detection, and a reverse tape positioning correction stage 204 for performing tape positioning correction in the case of reverse direction detection.

In the recording step, when the control unit stops the tape, the position processed on the tape is obtained and stored from the reel drive circuit, and when the control unit restarts, the control unit specifies the restart position to the reel drive circuit. A method of controlling a tape so that it can be processed from the same position is also one embodiment.

Further, in the recording step, in the forward direction, an IBG subsequent to the last normally processed data block is detected by the read / write circuit, and when the half of the prescribed value of the inter-block gap length is read. The tape position at this time is stored, and in the reverse direction, when the IBG following the last normally processed data block is read, a half of the prescribed value of the inter-block gap length is calculated from this position. It is also a preferred embodiment of the present invention to store the position shifted toward the end of the medium.

The tape positioning method according to the present invention is a tape positioning method in a magnetic tape device capable of positioning a tape by running in the reverse direction, and the tape positioning method is performed in the forward direction under the condition that the reading of the data block is completed and the data block is normally completed. Also in the direction, the positioning signal requesting step 801 for requesting the positioning signal in the IBG at the two positions of the middle and the end of the IBG, and the completion of the positioning signal transmission and the forward / reverse direction are discriminated. In this case, a second positioning signal transmission position is recorded, and a recording selection step 802 for selecting one of the two positioning signals, a stop processing step 803 for performing a tape stop processing by detecting a tape stop condition, and If so, there is a reverse tape positioning correction step 804 for performing a tape positioning correction.

In the recording step, when the control unit stops the tape, the position processed on the tape is obtained and stored from the reel drive circuit, and when the control unit restarts, the control unit specifies the restart position to the reel drive circuit. A method that is a storage control step of controlling a tape so that it can be processed is also an embodiment.

In the recording selection step, in the forward direction, an inter-block gap following the last normally processed data block is detected by a read / write circuit, and a half of a prescribed value of the inter-block gap length is read. Sometimes, the tape position at this time is stored. In the reverse direction, when the IBG following the last normally processed data block is read, half of the specified value of the inter-block gap length is read from this position. It is also a preferred embodiment of the present invention to store the position shifted toward the end of the medium by the length.

[0016]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment to which the tape positioning method of the present invention is applied. A high-level device 1 that sends commands to the magnetic tape device and exchanges data via the tape 4; a read / write circuit 2 for mutually converting the data format used by the control unit 8 and the head 3; A head 3 having a function of reading a magnetic signal of the tape 4 or recording data on the tape 4 by a magnetic signal, a tape 4 for recording or reading data, and winding / unwinding both ends of the tape 4 to form a tape It includes a reel 5 and a reel 6 for driving, a driving circuit 7 for driving the reel 5 and the reel 6 according to a command of the control unit 8, and a control unit 8 operated by the program control of the present invention.

Each of these components operates roughly as follows.

The read / write circuit 2 includes a read circuit 21
And a writing circuit 22.

The reading circuit 21 transmits the tape 4
Converts the analog signal read from to digital data,
The tape format is analyzed from the converted digital data. Then, it is decomposed into a block pattern (a data block (hereinafter, referred to as user data), a file mark, an erase gap, etc.) and an IBG, etc.
Each time an IBG is detected, the format analysis result is transferred together with the user data. If the writing operation to the tape 4 is being performed, the reading circuit 21 does not need to transfer the user data to the control unit 8. After reporting the format analysis result, if the control unit 8 determines that the analysis result is correct, the control unit 8 receives the information and sends a signal for tape positioning at the position specified by the control unit 8.
Send to The read circuit 21 reads the contents written to the tape 4 from the head 3 even if the magnetic tape device is performing a write operation (read check immediately after writing).
Perform the above operation.

A writing circuit 22 adds a IBG to user data, a file mark or the like to create a format for writing on the tape 4 according to a command from the control unit 8, converts digital data into an analog signal, and converts the digital data into an analog signal. 3
Send to The operation start condition of the read circuit 21 and the write circuit 22 is when an operation start signal is received from the drive circuit 7 after receiving each operation start command from the control unit 8.

The head 3 has a read head 31 and a write head 32. Read head 31 and write head 32
Are arranged so that the data written on the tape 4 by the write head 32 can be read by the read head 31. That is, the read head 31 is located at the beginning of the medium, and the write head 3 is located at the end of the medium.
2 are arranged.

The read head 31 reads a magnetic signal from the tape 4, converts the magnetic signal into an analog signal, and sends the analog signal to the read circuit 21.

The write head 32 converts the analog signal sent from the write circuit 22 into a magnetic signal and records data on the tape 4.

The drive circuit 7 operates the reel 5 and the reel 6 when receiving a command to start the operation of the tape 4 together with the processing start position of the tape 4 from the control unit 8. When the position of the tape 4 reaches the position designated by the control 8,
A signal for starting operation is sent to the read / write circuit 2. Further, when a signal for positioning the tape is received from the reading circuit 21, the position of the tape is reported to the control unit 8.

Next, a first embodiment of the tape positioning method of the present invention will be described in detail with reference to the flowchart of FIG.

First, during the reading and writing operations on the tape 4, the reading of the block is completed by the reading circuit 21 and the IBG is detected, so that the reading circuit 21 reports the format analysis result to the control unit 8. (Step 301 in FIG. 3). Next, when receiving the report of the format analysis result from the reading circuit 21, the control unit 8 determines whether the block has been read normally. If the data has been read normally (step 302, Yes), the operation direction of the tape 4 is checked.

If the operation direction of the tape 4 is the forward direction (step 303, Yes), the control unit 8 sends a command to the reading circuit 21 to send a positioning signal in the middle of the IBG (step 304). The middle of the IBG described here is an arbitrary IB actually recorded on the tape 4.
IB from the beginning of IBG, not the physical intermediate position of G
It refers to a position that is half the standard value of the G length.

If the operation direction of the tape 4 is the reverse direction (step 303, No), the control unit 8 reads the read circuit 2
A command to send a positioning signal at the end of the IBG is sent to 1 (step 305). At this time, since the operation of the tape 4 is operating in the reverse direction, the position where the positioning signal is transmitted is that the signal is transmitted at the IBG start position when viewed from the forward direction.

When the reading circuit 21 detects the positioning signal transmission position designated by the control unit 8, it notifies the driving circuit 7 of the detection signal transmission position. When the drive circuit 7 detects the positioning signal from the reading circuit 21, the drive circuit 7 reports the position of the tape 4 at that time to the control unit 8. Upon receiving the report of the positioning position (step 306, Yes), the control unit 8 records the position of the tape 4 where the positioning signal has been generated (step 307). If the position where the positioning signal has been generated for the tape 4 has been recorded before, the position of the last generated positioning signal is overwritten and recorded.

Next, when a tape stop condition is detected based on a pre-programmed condition (step 308, Yes), the control unit 8 sends an instruction for stopping the tape 4 to the drive circuit 7, and 4 is stopped (step 309).

If the tape 4 has stopped after the reverse operation (step 310, Yes), the above step 307 is executed.
Correction is made for the position of the tape 4 recorded in step (311). In this correction method, the value recorded in step A7 is changed to a value obtained by adding half the value of the IBG standard value.

Next, a specific example will be described. In this specific example, it is assumed that the standard value of IBG is 2 mm.

As shown in FIG. 4, when the tape 4 is being read in the reverse direction, the reading of the block ends at the tape position of 110 mm (step 301), and it is detected that the reading of the block has ended normally. (Step 30
2). Here, since the tape 4 is operating in the reverse direction (Step 303, No), the reading circuit 21 is requested to transmit the positioning signal at the end of the IBG (Step 305). As a result, the tape position 107m
The positioning signal is transmitted at the position of m, and the drive circuit 7 which has detected this signal reports the tape position to the control unit 8 (step 306, Yes). The control unit 8 sets the tape position 1 at this time.
07 mm is recorded and stored (step 307). At this time, since the control unit 8 does not satisfy the condition for stopping the tape 4 (step 308, No), the process of reading the next block is continued.

Next, the reading of the block is completed at the tape position of 103 mm (step 301), and it is detected that the reading of the block has been completed normally (step 3).
02). In the same procedure as above, the control unit 8 records and saves the tape positioning position 100 mm earlier than the drive circuit 7.
At this time, the control unit 8 detects a condition for stopping the tape 4 (step 308, Yes), so that the control unit 8 requests the drive circuit 7 to stop the tape 4 (step 307). When the tape 4 is next started up in the forward direction, the tape 4 can be sent to the read / write circuit 2 at a tape position of 100 mm at a position (point A in FIG. 4) where an operation start signal can be sent. ) (Step 309).

Here, since the direction in which the tape 4 was operated is the reverse direction (step 310, YES), the recorded tape positioning position is 100 mm and the IBG standard value is 2 mm.
Therefore, the tape position is updated to 101 mm. (Step 311).

FIG. 5 shows that after performing the operation shown in FIG.
This is the operation at the time of starting up in the forward direction.

In FIG. 4, when stopping at the point A, the tape positioning position is 101 mm. Therefore, when the tape is started in the forward direction from the point A in FIG. 5, the tape positioning position 100 lastly reported from the drive circuit 7 is obtained.
The operation start signal to the read / write circuit 2 is sent at the position of 101 mm after the correction, not at mm.

Next, the operation in the forward direction will be described with reference to FIG.

At the tape position of 100 mm, the reading of the block is completed (step 301), and it is detected that the reading of the block is completed normally (step 302).
Here, since the tape 4 is operating in the forward direction (step 303, Yes), the reading circuit 21 is requested to transmit the positioning signal in the middle of the IBG (step 304). As a result, a positioning signal is transmitted at a tape position of 101 mm.
Notifies the control unit 8 of the tape position. (Step 30
6, yes). The control unit 8 sets the tape position 101 m at this time.
m is recorded and stored (step 307). At this time,
Since the control unit 8 has detected the condition for stopping the tape 4 (step 308, Yes), the control unit 8 issues a request to stop the tape 4 to the drive circuit 7, and when the tape 4 is next started in the forward direction. Then, the tape stops at a position (point A in FIG. 6) where an operation start signal can be sent to the read / write circuit 2 at a tape position of 101 mm (step 3).
09). (If the operation is stopped from the forward direction, the tape temporarily stops at the point B. However, in preparation for the next start-up in the forward direction, when the vehicle travels in the reverse direction and reaches the point A, the positioning operation of the tape 4 is started. Here, the direction in which the tape 4 was operating is the forward direction (step 310, No), so that the tape positioning position is not corrected. FIG. 7 illustrates an operation when the operation is started in the forward direction after the operation illustrated in FIG. 6 is performed.

In FIG. 6, when stopping at the point A, the tape positioning position is 101 mm. Therefore, when the tape is started in the forward direction from point A in FIG. 7, the tape positioning position 101 last reported from the drive circuit 7 is obtained.
An operation start signal to the read / write circuit 2 is sent out at the position of mm. This is a rise at the same position as the forward direction after the operation in the reverse direction shown in FIG.

In this embodiment, a block has been described as an example. However, even if this block is a tape mark or an erase gap, the same processing can be performed. Next, a recording medium will be described.

The control program controls the operation of the data processing device read from the recording medium (10) by the data processing device (not shown) of the control unit. The control unit (8) executes the following processing under the control of the control program.

When the reading of the data block has been completed,
A positioning signal request process for requesting a positioning signal at the middle of the IBG in the forward direction and in the reverse direction at the end of the IBG in the forward direction, and a positioning signal transmission position record under the condition of the completion of the positioning signal transmission. , A process of stopping the tape by detecting a tape stop condition, and a process of performing a tape positioning correction in the case of reverse direction detection.

Next, the second method of the tape positioning method of the present invention will be described.
The embodiment will be described with reference to the flowchart of FIG.

First, during the reading and writing operations on the tape 4, the reading of the block is completed by the reading circuit 21 and the IBG is detected, so that the reading circuit 21 reports the format analysis result to the control unit 8. (Step 901). Next, when receiving the report of the format analysis result from the reading circuit 21, the control unit 8 determines whether the block has been read normally. If the data has been read normally (step 902, Yes), the control unit 8 sends the read circuit 21 the middle of the IBG and the IBG
(Step 903).

When the reading circuit 21 detects the positioning signal transmission position designated by the control unit 8, it notifies the driving circuit 7 of the detection signal transmission position. When the drive circuit 7 detects the positioning signal from the reading circuit 21, the drive circuit 7 reports the position of the tape 4 at that time to the control unit 8. When receiving the report of the positioning position (Yes in Step 904), if the operation direction of the tape is the forward direction (Yes in Step 905), the control unit 8 determines the position (I) of the tape 4 where the first positioning signal is generated.
The middle of BG is recorded (step 906). If the operation direction of the tape is the reverse direction (No in Step 905), the position of the tape 4 where the second positioning signal is generated (the end of the gap between blocks) is recorded (Step 90).
7). If the position where the positioning signal has been generated for the tape 4 has been recorded before, the position of the last generated positioning signal is overwritten and recorded.

Next, when a tape stop condition is detected according to a pre-programmed condition (step 908, Yes), the control unit 8 sends an instruction for stopping the tape 4 to the drive circuit 7, and 4 is stopped (step 909).

If the tape 4 has stopped after the reverse operation (step 910, Yes), the above-mentioned step 907 is performed.
The position of the tape 4 recorded in the step is corrected (step 911). In this correction method, the value recorded in step 907 is changed to a value obtained by adding half the value of the IBG standard value.

Next, a specific example will be described. In this specific example, it is assumed that the standard value of IBG is 2 mm.

As shown in FIG. 10, the control unit 8
Is read in the reverse direction, the reading of the block ends at the position of the tape position 110 mm (step 901).
It is detected that the reading of the block has been completed normally (step 902). Here, a request is made to the reading circuit 21 to transmit a positioning signal at the middle of the IBG and at the end of the IBG (step 903). As a result, positioning signals are sent at the tape positions of 109 mm and 107 mm, and the drive circuit 7 that has detected this signal reports the tape position to the control unit 8 (step 904, Yes). Since the operation direction of the tape is the reverse direction (No in Step 905), the control unit 8 records and saves the tape position 107 mm corresponding to the second positioning signal transmission position (Step 90).
7). At this time, since the control unit 8 does not satisfy the condition for stopping the tape 4 (step 908, No), the control unit 8 continues the process of reading the next block.

Next, the reading of the block is completed at the tape position of 103 mm (step 901), and it is detected that the reading of the block has been completed normally (step 9).
02). In the same procedure as above, the control unit 8 records and saves the tape positioning position 100 mm earlier than the drive circuit 7.
The data is overwritten by 7 mm and stored (step 907). At this time, since the control unit 8 has detected the condition for stopping the tape 4 (step 908, Yes), the control unit 8
, The tape 4 can send an operation start signal to the read / write circuit 2 at the tape position of 100 mm when the tape 4 is next started in the forward direction. It stops at the position (point A in FIG. 4) (step 909).

Here, since the direction in which the tape 4 was operating is the opposite direction (step 910, YES), the recorded tape positioning position is 100 mm, and the IBG standard value is 2 mm.
Therefore, the tape position is updated to 101 mm. (Step 911). Next, the recording medium will be described.

The control program is read from the recording medium (10) into a data processing device (not shown) of the control unit and controls the operation of the data processing device. The control unit (8) executes the following processing under the control of the control program.

A positioning signal requesting process for requesting a positioning signal in the IBG at two positions, the middle and the end of the IBG, in the forward direction and the backward direction under the conditions of the end of the reading of the data block and the normal end, the completion of the positioning signal transmission, and the reverse of the order A recording process for discriminating the direction, and performing a first positioning signal transmission position recording in the case of the forward direction and a second positioning signal transmission position in the case of the reverse direction; and a stop process of performing the tape stop process by detecting a tape stop condition. In the case of reverse direction detection, a reverse tape positioning correction process for performing tape positioning correction is executed.

[0055]

As described above, in the first embodiment, the present invention uses the positioning signal transmission positions at different positions in the forward direction and the reverse direction, and also achieves the second embodiment. In the embodiment, by selecting and using one of the positioning signal transmission positions irrespective of the forward / reverse direction, that is, the middle and the end of the IBG, for each direction later,
Regardless of whether the previous operation is performed in the forward / reverse direction, the restart position of the tape is the same amount (IBG) from the start end direction in the IBG.
Positioning at a position advanced by half the predetermined length of the length) has the effect of preventing data writing from an erroneous position, that is, a shifted position.

[Brief description of the drawings]

FIG. 1 is a block diagram of a tape positioning system of a magnetic tape apparatus to which a tape positioning method of the present invention is applied.

FIG. 2 is a flowchart showing processing of a first embodiment of a tape positioning method according to the present invention.

FIG. 3 is a detailed flowchart of the first embodiment of the tape positioning method of the present invention.

FIG. 4 shows a data tape position according to the first embodiment,
FIG. 9 is an operation explanatory diagram showing the relationship between signal transmission positions.

FIG. 5 is an operation explanatory diagram when the operation shown in FIG. 4 is performed and the apparatus is started up in the forward direction. (This drawing can be used commonly for the first and second embodiments.)

FIG. 6 is an explanatory diagram of an operation in the first embodiment in the case of forward direction → stop → forward direction.

FIG. 7 is an operation explanatory diagram of the first embodiment when operating in a forward direction from point A in FIG. 6;

FIG. 8 is a flowchart showing processing of a second embodiment of the tape positioning method of the present invention.

FIG. 9 is a detailed flowchart of a second embodiment of the tape positioning method of the present invention.

FIG. 10 is an operation explanatory diagram of the second embodiment showing the relationship between the data tape position and the signal transmission position.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper apparatus 2 Read / write circuit 3 Head 4 Magnetic tape 5 Reel 6 Reel 7 Drive circuit 8 Control part 10 Recording medium 21 Read circuit 22 Write circuit 31 Read head 32 Write head

Claims (8)

[Claims] 1. A tape positioning method for a magnetic tape device capable of positioning a tape by running in a reverse direction, comprising determining whether a data block has been read, has been normally completed, and determines whether the data block is forward or backward. , A positioning signal requesting step for requesting a positioning signal at the middle of the inter-block gap and in the opposite direction at the end of the inter-block gap (20).
1), a recording step (202) for recording a positioning signal transmission position under the condition of completion of the positioning signal transmission, a tape stop processing step (203) for performing a tape stop processing by detecting a tape stop condition, and If so, a tape positioning method in a magnetic tape device, including a tape positioning correction step (204) of performing a tape positioning correction. 2. The recording step, wherein when the control unit stops the tape, the position processed on the tape is obtained and stored from the reel drive circuit, and when the control unit restarts, the control unit specifies the restart position to the reel drive circuit; 2. The tape positioning method according to claim 1, further comprising a storage control step of controlling the tape to be processed from the same position. 3. In the recording step, in the forward direction, an inter-block gap following the last normally processed data block is detected by a read / write circuit, and a half of a prescribed value of the inter-block gap length is read. At that time, the tape position at this time is stored, and in the reverse direction, when the inter-block gap following the last normally processed data block has been read, half of the specified value of the inter-block gap length is calculated from this position. 3. The tape positioning method in a magnetic tape device according to claim 1, wherein a position shifted toward the medium end by the length is stored. 4. A recording medium in which a control program for positioning a tape is recorded in a magnetic tape device capable of positioning a tape by running in a reverse direction, wherein a data block read end, a normal end, and a forward / reverse direction are determined. A procedure for requesting a positioning signal at the middle of the inter-block gap in the forward direction, and a procedure for requesting the positioning signal at the end of the inter-block gap in the reverse direction, and a procedure of recording the positioning signal transmission position under the condition of the completion of the positioning signal transmission A procedure for performing a tape stop process by detecting a tape stop condition;
In the case of the reverse direction detection, a procedure for performing a tape positioning correction and a program for executing the procedure. 5. A tape positioning method in a magnetic tape device capable of positioning a tape by running in a reverse direction, wherein a gap between blocks can be reduced in a forward direction or a reverse direction under a condition of completion of data block reading and normal termination. Middle and end 2
A positioning signal requesting step (801) for requesting a positioning signal in an inter-block gap; determining whether the positioning signal has been transmitted and the forward / reverse direction; and determining the first in the forward direction and the second in the reverse direction. (A) a recording selection step (802) for recording the positioning signal transmission position and selecting one of the two positioning signals; (c) a stop processing step (803) for performing a tape stop processing by detecting a tape stop condition; If so, a tape positioning method in a magnetic tape device including a reverse tape positioning correction step of performing a tape positioning correction (804). 6. The recording selecting step, wherein when the control unit stops the tape, the position processed on the tape is obtained and stored from the reel drive circuit, and when the control unit restarts, the control unit specifies the restart position to the reel drive circuit. 6. The tape positioning method in a magnetic tape device according to claim 5, wherein the storage control step controls the tape to be processed from the same position. 7. In the recording selection step, in the forward direction, an inter-block gap following the last normally processed data block is detected by a read / write circuit, and a half of a prescribed value of the inter-block gap length is determined. At the time of reading, this is the stage of storing the tape position at this time, and in the reverse direction, when reading the inter-block gap following the last normally processed data block, the specified value of the inter-block gap length is calculated from this position. 7. The tape positioning method in a magnetic tape device according to claim 5, wherein the step of storing a position shifted toward the medium end side by half the length of the medium. 8. A recording medium in which a control program for positioning a tape in a magnetic tape device capable of positioning a tape by running in a reverse direction is recorded. However, in the reverse direction, the procedure for requesting the positioning signal in the inter-block gap at two places at the middle and the end of the inter-block gap, the completion of the positioning signal transmission, and the forward / reverse direction are determined.
In the case of the forward direction, the procedure of selecting the first positioning signal transmission position recording in the case of the reverse direction, the procedure of performing the tape stop processing by detecting the tape stop condition, and the procedure of performing the reverse direction detection, And a recording medium storing a program for executing a procedure for performing a tape positioning correction.