JPH05205404A - Format structure and formatting method for magnetic tape - Google Patents

Abstract

PURPOSE:To provide the format structure for magnetic tape which considerably increases the data access speed on a magnetic tape handling a large data volume and shortens the load/unload time of the magnetic tape to efficiently perform the data processing. CONSTITUTION:A magnetic tape 1 handles the large data volume and has the structure where plural data recording parts 6 each of which consists of a pair of a data area 5 and its reference area 3 are formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic tape format structure, and more particularly to a magnetic tape format structure for handling a large amount of data.

[0002]

2. Description of the Related Art Conventionally, as magnetic tapes, in addition to magnetic tapes that handle voice, which is analog information, digital data including image data handled by computing means such as computers, software for driving the computers, etc. Is also used. In the magnetic tape in the field of handling such digital data, usually, each one has a length of about 60 m, and the format of the magnetic tape is as shown in FIG. A reference area 2 is provided at the head portion (head portion) S of the magnetic tape 1, and at the same time, a data area 5 for storing or rewriting predetermined digital data is provided following the reference area 2. ..

The reference area 2 is composed of, for example, a load / unload area 3 and a tape management area 4. The loading / unloading area 3
Is data recorded in the form of a code to indicate that it is the head of the magnetic tape, and is used when searching the head of the magnetic tape.

On the other hand, in the tape management area 4, various information relating to the magnetic tape is recorded in an index form, for example, the number of the magnetic tape and the data area 5 of the magnetic tape are recorded. The type of data, the content of data, the length of data, etc. are stored as predetermined code information. When the data in the data area is rewritten and the data is updated, the tape management area The predetermined information is also rewritten according to its content.

The reference area 2 and the data area 5 of the magnetic tape generally form a data recording portion 6. The data length of the data area 5 of the magnetic tape is set to an arbitrary length as needed, and in some cases, an unformatted area which is not formatted near the end portion E of the magnetic tape. May exist.

In any case, since the conventional magnetic tape has a structure in which all the data are sequentially recorded according to the format, when reproducing the magnetic tape or rewriting predetermined data. In this case, it is necessary to return to the head position S of the magnetic tape before the reproduction is performed. If reproduction is started in the middle or data in the middle is rewritten, there is a problem that the data is destroyed due to scratches on the magnetic tape, or reproduction or rewriting becomes impossible.

Further, in the past, the data to be handled is
Since it was in a relatively small state, it was possible to use even a magnetic tape having such a format, but in recent years, computer-related technology has advanced and the amount of digital data to be handled has become enormous. In this case, since the magnetic tape of the conventional format is used, it is necessary to call the head position of the magnetic tape each time data is reproduced or updated, so it takes time to perform data processing and efficient data processing can be executed. Is becoming impossible.

In particular, recently, the DAT data storage, which is a computer to which the DAT technology is applied, has a large data capacity of 1 GByte, and since it is a magnetic tape, the search speed is a direct access device,
For example, the problem of being extremely slow compared to floppy desks has become apparent. Further, in order to unload the magnetic tape, a considerable amount of time is required considering the time required to fast-forward one magnetic tape and rewind it to the area where the magnetic tape is loaded / unloaded.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to improve the above-mentioned drawbacks of the prior art and to greatly improve the data access speed in a magnetic tape handling a large amount of data. The present invention provides a magnetic tape format structure capable of shortening the load / unload time of the magnetic tape and improving the efficiency of data processing time.

[0010]

In order to achieve the above-mentioned object, the present invention adopts the technical constitution as described below. That is, a magnetic tape for handling a large amount of data, in which a plurality of data recording portions each including a data area and a reference area of the data area are formed on one magnetic tape, In order to obtain the format structure of the magnetic tape, a first step of preparing a magnetic tape in which at least one data recording portion having a set of a data area and a reference area is formed, Set the data area on the tape to a predetermined data length and
A second step of creating a data recording portion of the first data recording portion, searching the end portion of the data area of the first data recording portion, and continuing to the new second reference area and the reference area following the end portion. A third step of forming a second data area having a predetermined data length to form a second data recording portion, and a predetermined number of data recording portions by repeating the third step a plurality of times. And a fourth step of successively forming a plurality of data recording portions by successively forming a plurality of data recording portions formed in front of the magnetic recording medium.

[0011]

Since the magnetic tape format structure and method for creating a format according to the present invention employ the above-described technical structure, one magnetic tape contains data composed of the reference area and the data area. A plurality of recording portions are formed, and one magnetic tape is physically regarded as a logical existence of a plurality of magnetic tapes.
Therefore, it is possible to access a predetermined data area storing predetermined data in a short time, and it is possible to significantly improve the data processing speed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific examples of the format structure of the magnetic tape according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram for explaining a specific example of the format structure of a magnetic tape according to the present invention. In the figure, a magnetic tape 1 is a magnetic tape for handling a large amount of data, and one magnetic tape is used. The tape 1 has a structure in which a plurality of data recording portions 6 each including a data area 5 and a reference area 3 of the data area 5 are formed.

In the present invention, the reference area 3 is composed of a tape management area 4 and a tape loading / unloading area 3. Further, the data length of the data area 5 of the data recording portion 6 can be set to an appropriate length for each data recording portion, and each data length is variable. Is preferred.

In FIG. 1, three sets of data recording portions 61, 62 and 63 are formed on one magnetic tape 1 and it is constructed as if there were three independent magnetic tapes.
In the magnetic tape 1, at the end portion E thereof,
The unformatted area portion 7 is left. According to the magnetic tape 1 of the present invention, a personal computer, a minicomputer, etc. are installed in a predetermined portion in an arithmetic processing unit, and a predetermined program is operated by using an appropriate command. As a result, it becomes possible to easily access the data area in the predetermined data recording portion of the magnetic tape in a short time, where necessary data can be read, written, or updated. I can.

In the conventional format of the magnetic tape, when the data in the data area of the data recording portion is updated, all the data after that is erased, but in the present invention, the data of the predetermined data recording portion is lost. When the data is updated, the data recorded in the data area of the data recording portion is destroyed or erased, but the data recorded in the other data recording portion is not affected at all.

In addition, adding other data to the data recorded in the data area of the predetermined data recording portion
The data recorded in the data area is not erased. Next, as a method for creating the above-described magnetic tape format structure according to the present invention, for example, a magnetic tape having at least one data recording portion 6 including a data area 5 and a reference area 2 as a set is formed. First step of preparing, second step of setting first data recording portion 61 by setting the data area 5 in the magnetic tape 1 to a predetermined data length, first data recording portion 61 Of the data area 5 is searched to form a new second reference area 2 following the end portion and a second data area 5 following the reference area 2 set to a predetermined data length. The third step of forming the second data recording portion 62 by repeating the third step is repeated a plurality of times, thereby sequentially forming a predetermined number of data recording portions and the data formed before the data recording portion. It is possible to use a method and a fourth step of forming a plurality of data recording portion was formed continuously in data recording portions.

Each step in the magnetic tape format creating method can be executed by inputting a predetermined command using a predetermined program. In the method of creating the format of the magnetic tape according to the present invention, the operator uses a predetermined keyboard to set the data length of the data area 5 in each of the data recording portions 61 to 63. It is also possible to select and decide.

In order to determine the data length and actually secure the data length, the last end portion 9 of the data area 5,
9'and 9 "can be set in advance, and the space between the final end 9 and the tape management area can be set by writing temporary data called an amble, for example. The data length of each data area 5 is set to a variable length, but once set, the data length cannot be changed, and the final data recording portion 63 of the magnetic tape is formed. Only the data area can be changed.

Therefore, after once setting the data length of the data area of each data recording portion, the data length cannot be made longer than the set length, but it is not possible to insert temporary data and use it short. It is possible. Further, since the data length of the data area is once set and fixed, if data having a length exceeding the data length of the data area of the data recording portion is written at the time of updating the data, the data area is continuously provided. There is a risk of destroying the data in the other data recording area.

Therefore, in the present invention, when data having a length exceeding the data length of the data area of the data recording portion is written, the remaining data length of the set data length and the data to be written from now on are written. It is preferable that a means for constantly comparing the data length to be provided is provided, and a predetermined warning is generated when the comparison value becomes equal to or less than a predetermined value.

Further, in the magnetic tape having the format structure according to the present invention, when the predetermined data is written in the data area 5 of the predetermined data recording portion, first, the magnetic tape is loaded into the predetermined rewriting means. After that, the operator can directly input the data area 5 by inputting an instruction to select a predetermined data recording portion into the computer from the keyboard, and then the data area 5 can be directly accessed.
The predetermined data is written in.

FIG. 3 shows an example of an apparatus for writing and updating appropriate data in a predetermined data recording portion of the magnetic tape while forming the format structure of the magnetic tape. A magnetic tape processing device 10 into which the magnetic tape 1 is inserted is controlled by a memory 12 and a firmware 11 that is connected to the memory 12 and has a ROMized program.

Further, the memory 12 and the firmware 11
Is controlled by a controller 13 including an interface called SCSI (Small Computor System Interface). The controller 13 is connected to a hard disk 14 and a host computer 15, and a RAM 16 and a keyboard are connected to the host computer 15. It has a configured configuration.

Next, the procedure for formatting the magnetic tape according to the present invention will be described with reference to the flowchart of FIG. When the format program is started, the format command is received from the computer in step (1), and at the same time, the logical tape number indicating the data recording portion of the magnetic tape to be processed is also received.

In this case, the received logical tape number is the logical tape number currently existing on the magnetic tape, or a number obtained by adding 1 to the logical tape number currently existing. The logical tape number is selected by the operator or the user in advance and input to the computer.

Then, in step (2), it is judged whether or not the logical tape number is 1. If YES in step (2), that is, if a completely new magnetic tape has been subjected to format processing, the magnetic tape is rewound in step (3) and the head S of the magnetic tape is rewound. Cue.

Then, in step (4), the data recording portion having the logical tape number 1 is formatted into a predetermined structure. In the step (2), NO
If it is, the process proceeds to step (5) to search for the last end of the number obtained by subtracting 1 from the logical tape number, and in step (6), the data area of the data recording part having the logical tape number. An amble process is performed on the data and temporary data is written to create a data recording portion having a predetermined data length.

Next, write predetermined data to a predetermined data recording portion of the formatted magnetic tape, or
Alternatively, FIG. 5 shows an operation procedure for updating to predetermined data.
The flowchart will be described. A mount which is a command for rewriting and updating data for mounting the magnetic tape on a predetermined data processing device is used. First, after the start, in step (1), the cassette of the magnetic tape processes the data. It is determined whether or not the device is loaded in the device. If NO, the operation is repeated again.

If YES in step (1),
In step (2), loading of the magnetic tape is executed, and then in step (3), the tape management area 4 forming the reference area of the magnetic tape is searched. Next, in step (4), the contents of the data stored in the tape management area 4 are read out, and in step (5), the head of the data area 5 of the magnetic tape is searched and its position is paused. It

Subsequently, in step (6), predetermined data is written or updated in the data area 5 of the magnetic tape by a predetermined command from the host computer using a predetermined program. Is done. FIG. 6 is a flowchart showing the procedure of the operation for ejecting the magnetic tape on which the data processing has been completed.

That is, this is executed by using an eject command for ejecting the magnetic tape from the magnetic tape processing apparatus. After the start, the eject command is received in step (1), and the step (2) is executed. Then, the tape management area of the magnetic tape is searched. In step (3), the data stored in the tape management area of the magnetic tape is updated in response to the data writing operation or the data updating operation of the data recording portion.

Then, in step (4), the load / unload area of the magnetic tape is searched, and in step (5), the magnetic tape is unloaded. Then, in step (6), the cassette of the magnetic tape is ejected. 7 is a flow chart showing an operation procedure for writing or updating data by accessing another data recording portion of the magnetic tape.

First, when a logical tape change operation is started using a command to change a logical tape, a tape change command is received from the host computer in step (1), and at the same time, the logical tape number to be changed is specified. To receive. Then, step (2)
At, the tape position of the designated logical tape number is searched, and the data in the tape management area of the logical tape is read in step (3).

After that, in step (4), the head portion of the data area in the data recording portion of the logical tape number is searched for and the position is paused, and in step (5), a predetermined area is written in the data area. The operation of writing data or updating the data in the data area to predetermined data is executed.

[0035]

Since the magnetic tape according to the present invention employs the format structure as described above, a plurality of individual magnetic tapes can be logically assembled even though it is one magnetic tape. Since it has a structure that is composed of
Since each magnetic tape part can be directly accessed independently of other magnetic tapes, the access speed to the data is improved, especially when reading, writing, and updating large-capacity digital data. Since the unload time can be remarkably shortened, the data processing time can be made efficient and speeded up.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a format structure of a magnetic tape according to the present invention.

FIG. 2 is a diagram showing an example of a format structure of a conventional magnetic tape.

FIG. 3 is a block diagram showing an example of an apparatus for forming a format structure of a magnetic tape according to the present invention.

FIG. 4 is a flowchart showing an operation example for executing a forming process of a magnetic tape format structure according to the present invention.

FIG. 5 is a flowchart showing an operation example for executing data processing of the magnetic tape according to the present invention.

FIG. 6 is a flowchart showing another operation example for executing the data processing of the magnetic tape according to the present invention.

FIG. 7 is a flowchart showing another operation example for executing data processing of the magnetic tape according to the present invention.

[Explanation of symbols]

 1 ... Magnetic tape 2 ... Reference area 3 ... Load / unload area 4 ... Tape management area 5 ... Data area 6 ... Data recording area 7 ... Unformatted area 9, 9 ', 9 "... End area of data area 61, 62 , 63 ... Data recording part 10 ... Data processing device of magnetic tape 11 ... Firmware 12 ... Memory 13 ... SCSI controller 14 ... Hard disk 15 ... Host computer 16 ... RAM 17 ... Keyboard

Claims (5)

[Claims] 1. A magnetic tape for handling a large amount of data, wherein a plurality of data recording portions each including a data area and a reference area of the data area are formed on one magnetic tape. A magnetic tape format structure that is characterized. 2. The magnetic tape format structure according to claim 1, wherein the reference area comprises a tape management area and a tape load / unload area. 3. The format structure according to claim 1, wherein the length of the data area of the data recording portion is configured to be variable for each data recording portion. 4. A first step of preparing a magnetic tape on which at least one data recording portion, which is a set of a data area and a reference area, is prepared, and the data area on the magnetic tape has a predetermined data length. Set to 1st
A second step of creating a data recording portion of the first data recording portion, searching the end portion of the data area of the first data recording portion, and continuing to the new second reference area and the reference area following the end portion. A third step of forming a second data area having a predetermined data length to form a second data recording portion, and a predetermined number of data recording portions by repeating the third step a plurality of times. And a fourth step of sequentially forming a plurality of data recording portions by successively forming a plurality of data recording portions before the formation of the data recording portion. 5. A step of writing data in a data area of an arbitrary data recording portion in the plurality of data recording portions and a step of changing data stored in the data area of the arbitrary data recording portion. The method for creating a format of a magnetic tape according to claim 4, wherein