JP2000293801A - Magnetic tape device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To speed up the recording or the reproducing of data by performing recordings or reproductions simultaneously to both surfaces of a magnetic tape. SOLUTION: Relating to a magnetic tape device having a head for the surface and a head for the back face for recording and reproducing data on the both sides of the magnetic tape, the device is provided with a data buffer 2 storing temporarily data which are to be recorded on the magnetic tape and data which are to be transferred to a host device, a dividing circuit 3 dividing data which are stored in the data buffer 2 and which are to be recorded on the tape, a write-in circuit for the surface 5 supplying data which are to be recorded on the surface of the tape between data divided in the dividing circuit 3 to a head for the surface 9, a write-in circuit 6 supplying data which are to be recorded on the back face of the tape between data divided in the dividing circuit 3 to a head for the back face 10, a read-out circuit for the surface 7 reading out the data read out with the head for the surface 9, a read-out circuit for the back 8 reading out the data read out with the head for the back face 10 and a restoration circuit 4 restoring data for transmission to the host device from the data read out in the read-out circuit for the surface 7 and the data read out in the read-out circuit for the back face 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetic tape device, and more particularly to a magnetic tape device capable of recording and reproducing data on both sides of a magnetic tape.

[0002]

2. Description of the Related Art Various types of magnetic tape devices having a front head and a rear head for recording and reproducing data on both sides of a magnetic tape have been known. An example of such an apparatus is disclosed in JP-A-5-67325.
There is a magnetic tape device disclosed in Japanese Unexamined Patent Publication (Kokai) No. H10-26095. In the magnetic tape device capable of double-sided recording and reproduction described in this publication, data to be recorded is continuously recorded on one surface, for example, the surface,
By recording data to be recorded continuously on the back surface when the recording on the front surface of the magnetic tape is completed to the end, recording and reproduction of a large amount of data is enabled.

On the other hand, various improvements have been made to the magnetic tape device in order to improve the data transfer speed with a host device. To improve the data transfer speed, it is essential to improve the recording density of the magnetic tape, that is, to improve the performance of the recording / reproducing head and the performance of the magnetic material of the tape medium.

[0004]

However, basic research is required to improve the recording density of the magnetic tape / performance of the head and the magnetic material of the tape medium, and a dramatic improvement in these performances is required. It was difficult. In addition, research and manufacture of new heads and media are extremely expensive,
There is a problem that the manufacturing cost of the magnetic tape device employing these increases.

Although the conventional double-sided magnetic tape device described above can increase the recording capacity, the data is continuously recorded on the front or back surface of the magnetic tape as it is. The time is no different from the example using only one side, and the processing time required for recording and reproducing data cannot be reduced. For this reason, it has not been possible to cope with an increase in the speed of recording and reproducing data in a storage device that has recently been highly demanded.

An object of the present invention is to solve the above-mentioned problems and to provide a magnetic tape device capable of speeding up data recording and reproduction.

[0007]

According to the magnetic tape device of the present invention, in a magnetic tape device capable of recording and reproducing data on both sides of a magnetic tape, data to be recorded is divided, and the divided data is recorded on both sides of the magnetic tape. The data is simultaneously recorded and reproduced from both sides of the magnetic tape at the same time to restore the data, and the restored data can be transferred to a higher-level device as reproduced data.

In the present invention, the data to be recorded is divided into two parts, and the divided data is simultaneously recorded on both sides of the magnetic tape, and simultaneously reproduced from both sides of the magnetic tape to restore the data. Can be transferred as reproduction data. Therefore, compared to the case where recording / reproduction is performed using only one side of the tape and the case where both sides are used but recording / reproduction is performed one by one as in the above-described conventional example, both sides of the magnetic tape are compared. Since they are used at the same time, the processing time inside the device can be shortened, and the speed of data recording and reproduction can be increased. As a result, the data transfer speed to the host device is dramatically improved.

More specifically, in a magnetic tape device having a front head and a back head for recording and reproducing data on both sides of a magnetic tape, data to be recorded on the magnetic tape or data to be transferred to a higher-order device. A data buffer for temporarily storing data, a dividing circuit for dividing data to be recorded stored in the data buffer, and data to be recorded on the surface of the magnetic tape among the data divided by the dividing circuit. A writing circuit for supplying to the head for front surface, a writing circuit for back surface for supplying data to be recorded on the back surface of the magnetic tape among the data divided by the division circuit to the head for back surface, Front surface read circuit for reading reproduced data, and back surface read circuit for reading data reproduced by the back surface head , Characterized in that it comprises a and a restoration circuit for restoring the transferred data to the host device from the data read in the data and the rear surface reading circuit read by the reading circuit said surface. By configuring the apparatus in this way, both sides of the tape can be simultaneously recorded and reproduced on the magnetic tape, and the data transfer speed with the host apparatus can be improved.

In a magnetic tape device according to the present invention, in a magnetic tape device having a front head and a rear head for recording and reproducing data on both sides of a magnetic tape, data to be recorded is divided or A data division / restoration circuit for restoring reproduced data, and of the data divided by the data division / restoration circuit, write data for a surface to be recorded on the surface of a magnetic tape is stored or reproduced from the surface of the magnetic tape. A front surface data buffer for storing front surface read data, a front surface write circuit for supplying the front surface write data stored in the front surface data buffer to the front surface head, and a front surface read data reproduced by the front surface head. A reading circuit for the surface to be supplied to the data buffer for the surface, and data divided by the data dividing and restoring circuit. A back-side data buffer for storing back-side write data to be recorded on the back side of the magnetic tape or for storing back-side read data reproduced from the back side of the magnetic tape; and a back-side write buffer stored in the back side data buffer. A back side write circuit for supplying data to the back side head, and a back side read circuit for supplying back side read data reproduced by the back side head to the back side data buffer may be provided. .

If the magnetic tape is constructed as described above, two independent data buffers are provided for the front side and the back side. For example, when data is recorded / reproduced, processing on one side of the tape becomes an error and retrying is performed. It is only necessary to temporarily hold the one that could be recorded and reproduced normally and to retry only the side where the error occurred, compared to the type that reprocesses both sides of the magnetic tape at the same time. Processing can be simplified.

[0012]

FIG. 1 is a block diagram showing the configuration of a magnetic tape device according to an embodiment of the present invention. In the embodiment shown in FIG. 1, a magnetic tape device 1 includes a data buffer 2, a data dividing circuit 3, a data restoring circuit 4, and write circuits 5, 6 and read circuits 7, 8 for the front and back surfaces of the tape. And heads 9 and 10 for the front and back surfaces of the tape. The host device 11 transfers data to and from the magnetic tape device 1 and supplies data to be recorded to the magnetic tape device 1 or
Receives data reproduced from.

In the example shown in FIG.
Is a temporary data storage location when data is transferred between the magnetic tape device 1 and the host device 11. The dividing circuit 3 is a circuit for dividing the data in the data buffer 2. The write circuits 5 and 6 are circuits that transfer signals obtained by converting data from the division circuit 3 to the head 9 for the front surface and the head 10 for the back surface. The read circuits 7 and 8 are circuits that convert signals from the front surface head 9 and the back surface head 10 into data. The restoration circuit 4 is a circuit that receives data from the read circuits 7 and 8 and restores the data. The surface head 9 is a writing and reading head for the surface of the tape.
The back surface head 10 is a write and read head for the back surface of the tape.

In this magnetic tape device, when writing data to the magnetic tape device 1, the host device 11 transfers data to be recorded on the magnetic tape device 1. The transferred data is sent to the dividing circuit 3 via the data buffer 2. The division circuit 3 divides the data to be recorded, which is stored in the data buffer 2, into the write data for the front surface and the write data for the back surface alternately in the order of transfer. That is, as shown in FIG. 2A, an example of data division is shown. Write data 20 from the host device is alternately and equally divided into write data 21 for the front surface and write data 22 for the back surface. afterwards,
In the example shown in FIG.
The signal is converted into a signal by the front surface writing circuit 5 and is written from the front surface head 9 to the tape surface. At the same time, the back side write data 22 is converted into a signal by the back side write circuit 6 and written from the back side head 10 to the tape back side.

When data is read from the magnetic tape device 1, a signal from the front head 9 is sent to the front reading circuit 7 and converted into data. At the same time, a signal from the back surface head 10 is sent to the back surface read circuit 8 and converted into data. The converted data is sent to the restoration circuit 4 respectively. The restoration circuit 4 performs data restoration by alternately reading the front surface read data supplied from the front surface read circuit 7 and the back surface read data supplied from the back surface read circuit 8, and rearranging the read order. That is, as shown in FIG. 2B, an example of data restoration is shown in FIG. 2A using the front surface read data 26 from the front head 9 and the back surface read data 27 from the back head 10. The read data 25 is restored by performing a process opposite to the division at the time of writing. Thereafter, in the example shown in FIG. 1, the restored data is transferred to the host device 11 via the data buffer 2.

As described above, if the data to be recorded is divided into two parts and the data is recorded on the front and back surfaces of the magnetic tape at the same time or they are read simultaneously, at least the processing required for driving the magnetic tape to travel and the device The load is reduced, and the data processing time inside the device is shortened. As a result, the speed of data transfer with the host device can be improved.

FIG. 3 is a block diagram showing the configuration of another embodiment of the magnetic head device of the present invention. In the embodiment shown in FIG. 3, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In the embodiment shown in FIG. 3, data buffers for storing data to be recorded or data to be transferred to a higher-level device are provided independently for the front side and the back side.

In the magnetic tape device shown in FIG. 3, when writing data to the magnetic tape device 1, the host device 11 transfers data to be recorded to the magnetic tape device 1. The transferred data is divided into front-side write data and back-side write data by the data division / restoration circuit 31,
The front side write data is sent to the front side data buffer 32, and the back side write data is sent to the back side data buffer 33. The front surface write data of the front surface data buffer 32 is supplied to the front surface head 9 via the front surface write circuit 5, and a signal is written on the tape surface. At the same time, the write data for the back surface of the data buffer 33 for the back surface is supplied to the head 10 for the back surface via the write circuit 6 for the back surface, and a signal is written on the back surface of the tape.

On the other hand, when data is read from the magnetic tape device 1, a signal reproduced by the front surface head 9 is sent to the front surface read circuit 7 and converted into front surface read data. At the same time, the signal reproduced by the back surface head 10 is sent to the back surface read circuit 8 and converted into back surface read data. The converted front side read data is sent to the front side data buffer 32, and the back side read data is sent to the back side data buffer 33. Each buffer 3
The data 2 and 33 are sent to the host device 11 after being restored by the data division restoration circuit 31.

The division of the data to be recorded in the data division and restoration circuit 31 is performed by alternately dividing the data to be recorded into write data for the front surface and write data for the back surface in accordance with the recording order. The data restoration in the data division restoration circuit 31 is executed by alternately reading and rearranging the front side read data stored in the front side data buffer 32 and the back side read data stored in the back side data buffer 33. .

Even when the magnetic tape device is configured as described above, the same effects as those of the magnetic tape device shown in FIG. 1 can be obtained. That is, since the same amount of data is transferred by half the tape travel distance as compared with the conventional double-sided magnetic tape, the internal load of the apparatus is reduced and the processing time is shortened. Data transfer speed can be improved.

Further, in the magnetic tape device shown in FIG. 3, by providing the data buffers for the front side and the back side independently, a read / write error occurs on one side of the magnetic tape during operation of the apparatus. In such a case, it is possible to temporarily wait for the normally operating data in the data buffer, and to retry only the one side in which an error has occurred. Therefore, the reliability of the apparatus is improved, and the processing can be simplified as compared with a configuration in which retry is performed on both sides when an error occurs.

[0023]

As is apparent from the above description, according to the present invention, the data to be recorded can be divided, and the divided data can be simultaneously recorded on both sides of the magnetic tape, and can be reproduced simultaneously from both sides of the magnetic tape. The system is designed so that data can be restored and the restored data can be transferred as playback data.Therefore, compared to the case where only one side of the tape is used and the case where both sides are used, recording and playback of the Both sides can be used at the same time, and high-speed data recording and reproduction can be achieved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a magnetic tape of the present invention.

FIGS. 2A and 2B are diagrams for explaining a data dividing method and a data restoring method, respectively.

FIG. 3 is a block diagram showing a configuration of another embodiment of the magnetic tape of the present invention.

[Description of Signs] 1 Magnetic tape device 2 Data buffer 3 Dividing circuit 4 Restoration circuit 5 Front writing circuit 6 Back writing circuit 7 Front reading circuit 8 Back reading circuit 9 Front head 10 Back head 11 Upper device 20 Write data 21 Front side write data 22 Back side write data 25 Read data 26 Front side read data 27 Back side read data 31 Data division restoration circuit 32 Front side data buffer 33 Back side data buffer

Claims (7)

[Claims] In a magnetic tape device capable of recording and reproducing data on both sides of a magnetic tape, data to be recorded is divided, the divided data is simultaneously recorded on both sides of the magnetic tape, and simultaneously reproduced from both sides of the magnetic tape. A magnetic tape device characterized in that the data is restored and the restored data can be transferred to a higher-level device as reproduction data. 2. A magnetic tape device having a front head and a back head for recording and reproducing data on both sides of a magnetic tape, wherein data to be recorded on a magnetic tape or data to be transferred to a host device is temporarily stored. A data buffer to be stored in the data buffer; a dividing circuit for dividing the data to be recorded stored in the data buffer; and data to be recorded on the surface of the magnetic tape among the data divided by the dividing circuit. A write circuit for supplying the front surface, a write circuit for the back surface for supplying data to be recorded on the back surface of the magnetic tape among the data divided by the division circuit to the head for the back surface, and data reproduced by the head for the front surface A readout circuit for the front side for reading data, a readout circuit for the backside for reading data reproduced by the head for the backside, 2. The magnetic tape device according to claim 1, further comprising: a restoration circuit for restoring transfer data to a higher-level device from data read by a read circuit and data read by the back surface read circuit. 3. The method of dividing data in the dividing circuit,
3. The magnetic tape device according to claim 2, wherein data to be recorded stored in the data buffer is alternately divided into front side write data and back side write data in accordance with the recording order. 4. A method for restoring data in the restoration circuit,
3. The magnetic tape device according to claim 2, wherein the front surface read data supplied from the front surface read circuit and the back surface read data supplied from the back surface read circuit are alternately read and rearranged in the read order. 5. A magnetic tape device having a front head and a back head for recording and reproducing data on both sides of a magnetic tape, wherein the data to be recorded is divided or the reproduced data is restored. A data dividing / restoring circuit, for storing front surface write data to be recorded on the surface of the magnetic tape among the data divided by the data dividing / restoring circuit, or for storing front surface read data reproduced from the surface of the magnetic tape; A data buffer, a front surface write circuit for supplying the front surface write data stored in the front surface data buffer to the front surface head, and a front surface read data reproduced by the front surface head, supplied to the front surface data buffer A readout circuit for the front surface, and data recorded on the back surface of the magnetic tape among the data divided by the data division and restoration circuit A back-side data buffer for storing back-side write data to be stored or for storing back-side read data reproduced from the back side of the magnetic tape; and supplying the back-side write data stored in the back-side data buffer to the back-side head. 2. The magnetic tape device according to claim 1, further comprising: a writing circuit for the back surface, and a reading circuit for the back surface for supplying the back surface read data reproduced by the back surface head to the back surface data buffer. 6. The division of data to be recorded in the data division / restoration circuit is performed by alternately dividing the data to be recorded into write data for the front surface and write data for the back surface according to the recording order. A magnetic tape device according to claim 1. 7. The data restoration in the data division restoration circuit is performed by alternately reading and rearranging front side read data stored in the front side data buffer and back side read data stored in the back side data buffer. Item 6. A magnetic tape device according to Item 5.