JPH1153869A - Magnetic tape controller and positioning control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid useless wiring and reading to/from an unreadable defective block by enabling high speed positioning of a magnetic head to a tape mark and a data block on a magnetic tape. SOLUTION: A tape information management area is provided to the beginning of tape(BOT) area of tape from which recording can be started and moreover a management area 2 for registration management of position information of tape marks 5, 6,... and a management area 3 for registration management of position information of unreadable defective data block among the data blocks 4 are also provided. The tape mark position information and defective data block position information written and registered to the management areas 2 and 3 are updated through the reference. During the loading period, the magnetic head is positioned at high speed to the track (#2) where the target tape mark 6 exists. Thereafter, the magnetic head is sequentially moved in unit of one data block to the data block 1 within the track for the positioning to the target tape mark 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic tape control device and a position control method which enable a magnetic head to be positioned at high speed and efficiently at a tape mark or a data block which is a delimiter of recorded information on a magnetic tape.

[0002]

2. Description of the Related Art Generally, in a magnetic tape control device, when writing information or reading information recorded in each data block with a target at a tape mark or data block on a magnetic tape, a target tape mark or data block is read. Until a data block is detected, 1
Reading has been performed for each data block. Such a troublesome procedure makes high-speed positioning on the magnetic head difficult.

A high-speed positioning system proposed as a target for high-speed positioning is disclosed, for example, in Japanese Patent Application Laid-Open No. 4-286018. In this case, the positions of the tape marks, data blocks and tape marks on the magnetic tape are tabulated. By recording it on a magnetic tape and associating the logical block ID with the physical block ID, the positioning is speeded up and the efficiency is improved.

[0004]

However, the high-speed positioning system disclosed in Japanese Patent Application Laid-Open No. 4-286018 has the following problems to be solved.

Until a target data block or tape mark is detected, data blocks are read one by one from the head of the tape. In some cases, a bad data block that cannot be read is detected during the block reading, but the corresponding processing is to perform only the erasing processing on the detected bad data block. Therefore, there is a possibility that data may be written again to the same defective data block portion, and no measures have been taken to avoid such inconvenience of overwriting.

Accordingly, a main object of the present invention is to provide a magnetic tape control device which enables high-speed positioning of a magnetic head to a target tape mark or data block on a magnetic tape and greatly improves the efficiency of recording and reading. And a positioning control method.

It is another object of the present invention to provide a magnetic tape control device and a control method capable of avoiding wasteful reading and writing of unreadable bad data blocks and improving the reliability of processing. is there.

[0008]

SUMMARY OF THE INVENTION A magnetic tape control device according to the present invention is a device for positioning a target tape mark or data block on a magnetic tape on a magnetic head. Department (BOT)
The unit is provided with a tape mark position information management unit that registers and manages the position information of the tape mark, and a bad data block position information management unit that registers and manages the position information of the unreadable bad data block among the data blocks. .

[0009] In this case, the one tape mark position information management section stores a plurality of track numbers on the magnetic tape,
The tape mark position information including the tape mark number and the data block ID number in these tracks is registered and stored, and the stored tape mark position information can be updated by referring to the stored tape mark position information.

[0010] The other defective data block position information management section stores the defective data block position information comprising the numbers of a plurality of tracks on the magnetic tape and the ID numbers of the unreadable defective data blocks in these tracks. It is registered and stored, and the upper-level device can refer to and update the stored defective data block position information.

A magnetic tape positioning control method according to the present invention comprises:
A tape mark position information management unit is provided at the tape start end (BOT) of the magnetic tape at which recording is started, where the number of a plurality of tracks on the magnetic tape, the number of the tape mark in these tracks, and the data block The tape mark position information including the ID number is written and registered.

At the time of loading by inserting a magnetic tape, the target device of the registered tape mark position information is referred to by the host device, and the magnetic head is positioned at a high speed to the track where the target tape mark is located.

Next, after high-speed positioning on this track,
The magnetic head is sequentially moved to data blocks in the track in data block units, and positioned at a target tape mark.

In another aspect of the magnetic tape positioning control method according to the present invention, the BOT unit is provided with a defective data block position information management unit, in which a plurality of track numbers on the magnetic tape, ID of unreadable bad data block among data blocks in
The bad data block position information including the number is written and registered.

In this case, when a defective data block is detected during processing at the time of loading by inserting a magnetic tape, the defective data block position information registered in the defective data block position information management unit of the BOT unit by the host device is deleted. refer.

Next, the total number of error retries in the track where the detected defective data block is located is set to 1
If the number of times of increase is larger than the predetermined number, the flag signal in the track is set to 1 and then the defective data block is erased.

Therefore, when the target tape mark or data block on the magnetic tape is positioned on the magnetic head by the above apparatus and control method, the target of the registered tape mark position information is determined by the host apparatus. The magnetic head is positioned at a high speed to the track where the target tape mark is located by referring to the reference.

Then, the magnetic head is sequentially moved to the data block in the track in units of one data block, and positioned at the target tape mark.

That is, in the first stage, the magnetic head is moved to the track at a high speed and is positioned at the target tape mark within the track. Can be positioned at high speed.

When a defective data block is detected, it is not limited to simply erasing the defective data block, but it is written and registered once, and the flag signal of the track where the data block is located is erased. It is possible to avoid the inconvenience of unnecessary reading and writing of possible defective data blocks.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a magnetic tape control device and a positioning control method according to the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram schematically showing a data recording image on a magnetic tape and the operation of a magnetic head corresponding thereto. Start of tape (B
In an OT (Beginning Of Tape) section, a tape information management area 1 which is the gist of the present invention is provided. This tape information management area 1 is defined by a tape mark position information management unit 2 and a bad data block position information management unit 3.

On the magnetic tape, following the BOT section, each data block following the first data block 4 and the first # 1 tape mark 5 are provided for each track.

As shown in FIG. 3, the tape mark position information management section 2 of the tape information management area 1 in the BOT section stores track numbers # 1, # 2, # 3,.
.. and data block 4 corresponding to each track
ID numbers and tape marks 5, 6 (# 1, # 2,...)
")" And "tape mark position information" can be stored and stored. In a higher-level device (not shown), the above-described tape mark position information can be referred to and updated.

As shown in FIGS. 2 and 4, the bad data block position information management section 3 has an arbitrary number of track numbers # 1, # 2, # 3,.
.. And the defective data block position information of the ID numbers # 1, # 2, # 3,... Of the arbitrary number of defective data blocks 7 in each track can be registered and stored. The host device can refer to the position information and update it.

In the above configuration, the operation of referring to and updating the tape mark position information in the tape mark position information management unit 2 will be described with reference to FIGS.
This will be described with reference to the operation flowchart of FIG. 6B and FIGS. 6A and 6B.

As shown in FIG. 5 (a), at the time of loading with a magnetic tape inserted, the host device reads the tape mark position information management unit 2 of the BOT unit, and reads “tape” consisting of a track number and a data block ID number. Mark position information "is referred to (step S1).

During execution of some processing, FIG.
As shown in (b), for example, when the tape mark 5 of # 1 is detected, the position information of the detected tape mark 5 is
It is determined whether or not the information is registered in the referenced tape mark position information (step S3). If not registered (N
o) Register and update the tape mark position information with reference to the data block ID number of the tape mark 5 (step S4).

As shown in FIG. 5B, when unloading the magnetic tape, the magnetic head is temporarily moved to the BOT section and rewinded (step S5). At this time, the tape mark position information updated in step S4 is written in the tape mark position information management unit 2 (step S6). Then, the magnetic tape is ejected (step S8).

Next, as shown in the operation flowchart of FIG. 7, when "tape mark high-speed positioning" is performed with reference to the tape mark position information, the following processing is performed.

At the time of loading with a magnetic tape inserted, the tape mark position information management unit 2 is read and the tape mark position information is referred to as in step S1.

In FIG. 7, when the magnetic head is positioned at, for example, the tape mark 6 of # 2 in the track # 2, it is determined whether or not the position information on the tape mark 6 of # 2 is registered in the referenced tape mark position information. (Step S20). If not registered (N
o), the magnetic head is positioned in units of one block toward the target tape mark 6 (step S2).
2). In step S23, # 2 tape mark 6
If the positioning of the tape mark is successful (Yes), the referenced tape mark position information is updated (step S24).

If it is determined in step S20 that the tape has been registered (Yes), the magnetic head is positioned at a high speed on the track where the target tape mark 6 of # 2 exists by using the referenced tape mark position information (step S20). S
21). Thereafter, the magnetic head is positioned in units of one block up to the target # 2 tape mark 6 (step S2).
2). If the positioning has failed in step S23 (No), the tape mark position information is updated (step S24).

At the time of unloading for discharging the magnetic tape, as shown in FIG. 5B, the magnetic head is moved to the temporary BOT portion and rewinded (step S5). Then, the updated tape mark position information is written into the tape mark position information management unit 2 (step S6). Thereafter, the magnetic tape is ejected (step S8).

Next, when a defective data block 7 is detected at the time of loading with a magnetic tape inserted, the processing is performed as shown in FIGS. 5 (a) and 6 (a). This will be described with reference to FIG.

The host device reads the "bad data block position information" by reading the bad data block position information management unit 3 in the tape information management area 1 in the BOT unit (step S2).

In this case, as shown in FIG. 6A, the ID of the track is stored in the referenced defective data block position information.
The number is registered (step S10), and the total error retry count of the track is increased by one (step S11). At this time, if the total number of error retries is large in step S12 (Yes), the flag of the defective track is set to 1 (step S13). Thereafter, the defective data block 7 is erased (step S14).

At this time, as shown in FIG. 5B, at the time of unloading by discharging the magnetic tape, the magnetic head is temporarily moved to the BOT section and rewinded (step S).
5) Write the updated bad data block position information to the bad data block position information management unit 3 (step S).
7). Thereafter, the magnetic tape is ejected (step S
8).

Next, the operation of reading and writing data blocks with reference to the defective data block position information will be described.

As shown in FIG. 5A, at the time of loading by inserting a magnetic tape, the defective data block position information management unit 3
And reads the defective data block position information (step S2).

As shown in FIG. 8A, when reading a data block, it is determined whether or not the next block to be read is a defective data block (step S30). ) Reads a data block (step S32). If it is a defective data block (Yes), the defective data block is skipped and the magnetic head is positioned at the next data block (step S31).

In FIG. 8B, when data is written to a data block, it is determined whether or not a defective track flag of a track to be written indicates 1 (step S40). If the defective track flag indicates 1 (Yes), the magnetic head is positioned on the next track (step S42). If the defective track flag does not indicate 1 (No), it is determined whether or not the next data block 8 is a defective data block (step S4).
2). If it is a defective data block (Yes), the defective data block is skipped, and the magnetic head is positioned at a data block next to the defective data block (the block erased in step S14) (step S44). If the data block is not defective but normal (No), the data block is written (step S4).
3).

[0043]

As described above, according to the magnetic tape control device and the positioning control method of the present invention, a tape mark position information management unit capable of writing and registering tape mark position information is provided in a BOT unit of a magnetic tape. Then, by referring to the tape mark position information, the positioning process to the target tape mark can be performed at high speed.

By providing a bad data block position information management unit for writing and registering position information of an unreadable bad data block in the BOT unit, useless reading / writing processing to the bad data block on the magnetic tape can be performed. It can be avoided and is very effective in improving reliability.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a data recording image of a magnetic tape and a magnetic head operation during a tape mark management process in an embodiment of a magnetic tape control device according to the present invention.

FIG. 2 is a schematic diagram showing a data recording image of a magnetic tape and a magnetic head operation at the time of a bad data block management process in the present embodiment.

FIG. 3 is a configuration diagram of a tape mark position information management unit.

FIG. 4 is a configuration diagram of a bad data block position information management unit.

FIGS. 5A and 5B are operation flowcharts showing control modes during insertion and ejection of a magnetic tape, respectively.

FIGS. 6A and 6B are operation flowcharts showing control modes when a defective data block is detected and when a tape mark is detected, respectively.

FIG. 7 is an operation flowchart showing a control mode of high-speed positioning of a tape mark.

FIGS. 8A and 8B are operation flowcharts showing control modes at the time of writing and reading a defective data block, respectively.

[Explanation of symbols]

 1 Tape Information Management Area 2 Tape Mark Position Information Management Unit 3 Bad Data Block Position Information Management Unit 4 Data Block 5 # 1 Tape Mark 6 # 2 Tape Mark 7 Bad Data Block 8 Bad Track

Claims (8)

[Claims] 1. A magnetic tape control device for positioning a target tape mark or data block on a magnetic tape to a magnetic head, comprising: a tape start end (BO) capable of starting recording on the magnetic tape.
T) a tape mark position information management unit for registering and managing the position information of the tape mark; a bad data block position information management unit for registering and managing the position information of the unreadable bad data block among the data blocks; A magnetic tape control device comprising: 2. The tape mark position information management section stores tape mark position information including numbers of a plurality of tracks on the magnetic tape, numbers of the tape marks and ID numbers of the data blocks in the tracks. 2. The magnetic tape control device according to claim 1, wherein the magnetic tape control device is configured to be registered and stored, and that the stored tape mark position information can be updated by referring to the higher-level device. 3. The bad data block position information management section stores bad data block position information comprising numbers of a plurality of tracks on the magnetic tape and ID numbers of unreadable bad data blocks in these tracks. The magnetic tape storage device according to claim 1, wherein the magnetic tape storage device is registered and stored, and is configured to be able to be updated by referring to the stored defective data block position information by a higher-level device. 4. A magnetic tape positioning control method for positioning a target tape mark or data block on a magnetic tape on a magnetic head, comprising: a tape start end (BO) of the magnetic tape at which recording is started.
In the tape mark position information management section provided in T), the tape mark position information including the numbers of the plurality of tracks on the magnetic tape, the tape mark numbers in these tracks, and the ID numbers of the data blocks is written. At the time of loading by inserting the magnetic tape, the target of the registered tape mark position information is referred to by a higher-level device, and the magnetic head is moved to the track where the target tape mark is located. Magnetic tape positioning after high-speed positioning on the track, and sequentially moving the magnetic head to the data block in the track in units of one data block to position the magnetic tape on the target tape mark. Control method. 5. When the positioning to the target tape mark is unsuccessful, the magnetic head is temporarily returned to the BOT section, and the tape mark position information management section of the BOT section is provided with the target tape mark. 5. The magnetic tape positioning control method according to claim 4, wherein the updated tape mark position information is written and registered, and then the magnetic tape is ejected (unloaded). 6. A magnetic tape positioning control method for positioning a target tape mark or data block on a magnetic tape to a magnetic head, comprising: a tape start end (BO) of the magnetic tape at which recording is started.
In the defective data block position information management unit provided in T), defective data including the numbers of a plurality of tracks on the magnetic tape and the ID numbers of the unreadable defective data blocks among the data blocks in these tracks When writing and registering the block position information, if a bad data block is detected during processing when loading by inserting the magnetic tape, the bad data block registered in the bad data block position information management unit by the host device With reference to the position information, if the number of times that the total number of error retries in the track where the detected defective data block is located is increased by one more than a predetermined number, the flag signal in that track is set to 1 and then Erasing the bad data block; positioning control of a magnetic tape; Law. 7. When the flag signal of the track where the defective data block is located indicates 1, the magnetic head is positioned on the next track, and when the flag signal does not indicate 1, the next data block is located. 7. The magnetic tape positioning control according to claim 6, wherein it is determined whether the block is a bad data block, and if the block is a bad data block, it is skipped and the magnetic head is positioned at a next data block. Method. 8. When unloading by discharging the magnetic tape, the magnetic head is temporarily returned to the BOT section,
7. The magnetic tape positioning apparatus according to claim 6, wherein the updated position information of the bad data block is written and registered in the bad data block position information management unit of the BOT unit, and then the magnetic tape is ejected. Control method.