JP3182129B2 - Storage medium and control method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exchangeable recording medium (storage medium) and a control method thereof, and more particularly to a storage medium supporting a plurality of types of logical formats and a control method thereof.

[0002]

2. Description of the Related Art In an optical disk, a laser beam has a diameter of about 1 μm.
Recording and reproduction of an information signal are performed by focusing on a minute light spot of m. For this reason, the recording density is high, the memory cost per bit can be reduced, and high-speed access is possible. Furthermore, recording and reproduction can be performed in a non-contact manner. Such optical discs are classified into two types: optical discs (ROM discs) on which information is recorded and reproduced only in advance, optical discs (RAM discs) on which information can be recorded and reproduced, and the above two types of optical discs. To be divided into partial ROM disks.

As shown in FIG. 17A, a ROM disk stores information in pits (concavities and convexities) 2 on a transparent plastic layer 1.
And a metal film (for example, aluminum) 3 is formed on the pit surface by vapor deposition or the like, and a protective layer 4 is provided thereon. In such a ROM disk, as shown in FIG. 17B, an objective lens O is formed on a signal layer (pits and a metal film).
When the laser beam RB is irradiated through the L, the light almost returns in a place where there is no pit, but is diffracted by the pit in a place where there is a pit, and the return light goes out of the field of view of the objective lens OL, and Only a part returns to the objective lens. Therefore, information can be read by detecting the return light with the photodiode. As described above, since information is recorded in pits on a ROM disk, the information is less likely to be broken than magnetic recording or the like.
In addition, there is an advantage that a large amount of information can be easily created by stamping, and is effective as a storage medium for electronic publications. However, the user cannot write a document or the like created by the user on the ROM disk.

A RAM disk (magneto-optical disk) is formed by depositing an amorphous magnetic thin film such as TbFeCo on a substrate, and the coercive force required for reversing the magnetization of the magnetic film decreases as the temperature rises ( The coercive force is zero at the temperature compensation point). That is, the recording by controlling the magnetization direction by multiplying the weak magnetic field state by irradiating a laser beam to raise the temperature of the disk medium to the vicinity of 200 ⁰ C weakened coercive force,
It is to be erased. Therefore, as shown in FIG. 18A, in the state where the magnetization direction on the magnetic film 5 is downward, an upward magnetic field is applied by the write coil 6 and FIG.
When the laser beam LB is irradiated through the objective lens OL to the portion where the magnetization direction is to be reversed as shown in (1), the magnetization direction of the portion is reversed and becomes upward, and information can be recorded.
In reading information, when the magnetic film 5 is irradiated with a laser beam LB having a plane of polarization in the y-axis direction as shown in FIG. Reflected light LB whose polarization plane is rotated by θ _K
0 is obtained, and in the portion where the magnetization direction is upward, reflected light LB1 whose polarization plane is rotated by θ _{K in the} counterclockwise direction is obtained. Therefore, by detecting the polarization state of the reflected light, the direction of magnetization, in other words, information can be read. Since the RAM disk is rewritable, the ROM
Unlike a disc, a user can freely write a document or the like created by himself / herself. Therefore, the RAM disk records fixed information such as a system program and a character font in a predetermined area and makes the area a write-protected area.
Other areas can be used as areas for recording user-created documents, additional information, and version-up information. However, in the case of a RAM disk, since it is necessary to write fixed information one by one thermomagnetically, it takes a long time to manufacture and increases the cost.

[0005] A partial ROM (partial ROM magneto-optical disk) includes a ROM area having the same structure as a ROM disk and a RAM area having the same structure as a RAM disk. For this reason, fixed information such as system programs and character fonts can be recorded in the ROM area by stamping.
There is no need to write one by one. Also, the user can freely write the created document in the RAM area. That is, the partial ROM has an area for storing fixed information on one disk (ROM area) and a rewritable area (RAM area).
Area).

According to the ISO standard, a 3.5-inch optical disk has approximately 10,000 concentric or spiral tracks on one side, and all the tracks are sector-shaped.
It is divided into 5 sectors (25 blocks). FIG. 19 is an explanatory diagram of the configuration of an optical disk based on the international standard (ISO standard). For convenience of explanation, a part of the disk is cut open, and block (sector) numbers (0 to 2) are set in the horizontal direction.
4) The vertical direction is a track number. Accessible area (user data zone) from the third track to the 9996 track where the user can access in the usual way
11 '. In the accessible area 11 ', the entire area is R
In the case of the AM unit 12 '(full RAM disk), in the case where the entire area is the ROM unit 13' (full ROM disk), there is a case of a partial ROM disk in which the RAM unit 12 'is inside and the ROM unit 13' is outside. Accessible area 1
Each of the three tracks inside and outside 1 'is provided with a defect management area DMA (Defect Management Area) 1.
4a and 14b are provided, and an inner control track (inner control zone) 15a, an outer control track (outer control zone) 15b, and margins 16a and 16b are provided on the inner and outer circumferences. The defect management area DMA is an area for managing error information when a defective sector occurs in the accessible area 11 ', a substitute sector, and the like.

[0007] the head of the accessible area 11 'as shown in FIG. 20, the partition management table area 11 ₁ is provided,
Thereafter, n divided areas (first to n-th divided areas) 11
₂₁ to 11 ₂ n are provided. Partition management table area 1
Reference numeral ₁₁ denotes an area in which information of each section (section information) is written. If divided into FIG 20 n compartments (first to n partitions) are shown, first the section management table area 11 ₁
To n-th section information 11 _{11 to} 11 ₁ n are written. Each partition information ₁₁ 11 to 11 ₁ n the start sector of the partition, the last sector, the number of sectors of the partition, the format of the compartment (e.g. DOS, UNIX, CD-ROM logical format, etc.), light that indicates whether rewrite disable A protection flag and the like are recorded. In addition, as described later,
Since the BPB (BIOS PARAMETER BLOCK) table is stored at the beginning of the section, the start sector indicates the position of the BPB.

[0008] compartment example, to describe the partition of DOS, as will each of the sections 11 ₂₁ to 11 ₂ n shown in FIG. 21,
BPB that describes information necessary for file management in a section
(BIOS PARAMETER BLOCK) A reserved sector including a table 17a, a file management area 17b for storing a file allocation table (FAT) and a directory,
A file area 17c for storing various files is provided. The BPB table 17a is provided at the head of the section and describes the volume structure parameters of the disk, the contents of which are standardized by ISO9293. The BPB table includes a sector length (the number of bytes per sector) SS, a cluster length (the number of sectors per cluster) SC, the number of FATs FN (= 2), the number of root directory entries RDE, and the number of entries in the logical volume. It describes the total number of sectors TS, the number of sectors per FAT, the number of sectors per track SPT, and the like.

The file management area 17b is provided with FAT entry sections 17b-1, 17b-2 and a directory entry section 17b-3. Each of the FAT entry sections 17b-1 and 17b-2 has duplicated first and second FATs (FILE ALLOCATIO
N TABLE) is recorded. That is, each FAT entry section has the number of FAT entries equal to the number of clusters of the partition, and takes a value of 0000,0002 to MAX, FFF7, FFFF, respectively. 0000 means that the cluster is unused, 0002 to MAX means that the cluster is in use, and the value indicates the next storage location of the file. FFF7 means that a sector constituting the cluster has a defect, and FFFF means the end of the file. Each directory entry in the directory entry section 17b-3 is composed of 32 bytes, and has a file name column 18a and a file name extension column 18 as shown in FIG.
b, attribute display field 18c, reserved area field 18d, file change time field 18e, file change date field 18f, file top cluster number field 18g, file size field 18h
have.

FIG. 23 is an explanatory diagram of a directory entry and a FAT entry indicating the storage location of the file name "FILE". The file "FILE" has a cluster number 0.
It is assumed to be stored in _{004 H → 0005 H → 0006 H} → 000A H. First cluster number of file ”
0004 ”is stored in the directory entry in association with the file name“ FILE. ”Cluster number 0
The FAT entry 004 stores a cluster number “0005” indicating the next storage location of the file. The FAT entry of the cluster number 0005 stores a cluster number “0006” indicating the next storage location of the file. The FAT entry of 0006 stores a cluster number “000A” indicating the last storage location of the file, and the FAT entry of cluster number 000A stores “FFFF” indicating the end of the file.

FIG. 24 is an explanatory diagram of file access of a personal computer using an optical disk as a recording medium. When inserting the optical disc into the disc drive, the system automatically reads the section management table 11 _1, to grasp the position of the compartments (e.g. the first compartment 11 _21). Next, the BPB table 17a recorded at the head of the section is read, and the BPB table 17a is read.
The FAT position and the directory position are ascertained by referring to the table, and the file area 1 is determined using the FAT and the directory.
Access the file 7a. Further, while the system is operating, the file access of another section is designated, the host system can recognize the head position of the compartment with reference to section management table 11 _1, recorded in the same manner compartment top The BPB table is read and the file of the designated section is accessed with reference to the BPB table.

[0012]

When a large-capacity exchangeable recording medium such as an optical disk is used, there is a demand that data in the recording medium be handled by various personal computers. Such a request arises, for example, when the company records a meeting material created using a personal computer of company A on an optical disk, takes the disk home, and edits it with a personal computer of company B at home. When such usage becomes possible, data recorded on the optical disk can be used anywhere as long as the user has the optical disk, which is very convenient. However, conventionally,
The data recorded on the optical disk could not be shared by the personal computers of each company. This is because the logical format for handling the optical disk differs depending on the personal computer manufacturer or the personal computer model, and the recording position of the partition management table differs depending on each company and each model. For this reason, the data of the part formatted by the personal computer of Company A cannot be handled by the personal computer of Company B.

FIG. 25 is an explanatory diagram of the logical format of each company. LBN is an abbreviation of LOGICAL BLOCK NUMBER and means a logical block address. A company (position information of the partition) 11 ₁ a section management table LBN1 a logical format
Here, the head position of each section, the size of the section, and the like are described. A BPB table is recorded in the first block of each of the sections 11 ₂₁ a and 11 ₂₂ a. The personal computer of Company A automatically reads LBN1 when a disc is inserted, and the head position of the section (the position of the BPB table), size, etc. Recognize. The B's logical format has (position information of the partition) 11 ₁ b partition management table LBN 0, the size of the compartment and the head position of the partition here is described. There is a BPB table in the first block of each of the sections 11 ₂₁ b and 11 ₂₂ b. Company B's PC is LBN when the disc is inserted
0 is automatically read to recognize the head position, size, etc. of the section. In the logical format of Company C, there is no partition management table, and the partitions start from LBN0. The BPB table is in the first block of the partition, ie, LBN0. The PC of company C automatically reads LBN0 when the disc is inserted, and recognizes the size of the section and the like.

The personal computer of Company A handles the optical disk according to the logical format (compartment management information, BPB information) of Company A, and considers that the section management table exists in LBN1.
Therefore, when a disk formatted in the logical format of Company B is inserted into the disk drive of the personal computer of Company A, the personal computer of Company A
The information recorded in N1 is read. However, since the partition management table is not written in LBN1, data cannot be read from or written to the optical disk of the logical format of Company B. The same applies to the opposite case. As described above, since the location of the BPB table or the partition management table differs between companies and models, one optical disc cannot be used by multiple models, and data recorded on the optical disc is shared by multiple models. Could not be used. Accordingly, an object of the present invention is to provide a storage medium that can be used in common by a plurality of models and a control method thereof. Another object of the present invention is to provide a file (data)
Is to provide a storage medium that can be used in common by a plurality of models and a control method thereof.

[0015]

FIG. 1 is an explanatory view of the principle of the present invention. Reference numeral 11 denotes a replaceable recording medium (storage medium) such as an optical disk, 101 denotes a first area, and 102 denotes a second area. In the first area 101, a file accessed by a plurality of computer devices (host systems) of different models and file management information (FAT, directory) common to the plurality of different computer devices are recorded. In the second region 102, the logical format information 102 ₁ ～102N required to manage the files by using a common file management information model stored in the first region
Are recorded in correspondence with the model of each computer device. Each of the logical format information 102 ₁ to 102 n includes
Address information necessary to read the common file management information model stored in the first area 101 (the number of reserved sectors, etc. sector length) is included AD _1-ADn.

[0016]

The logical format information 1 necessary for managing a file by using the file management information (FAT, directory) common to the models recorded in the first area 101.
02 _{1 to} 102 n are recorded in the second area 102 in correspondence with the model of each computer device. When the replaceable recording medium 11 on which the logical format information 102 _{1 to} 102 n is recorded according to the model is mounted, the computer device (personal computer) reads the logical format information according to the model from the second area 102, Based on the read logical format information, file management is performed by using file management information common to the models recorded in the first area 101. In this way, one interchangeable recording medium can be used in common by a plurality of types of computer equipment, and a file recorded on the interchangeable recording medium can be shared by a plurality of types of computer equipment. It can be commonly used by devices.

In this case, each logical format information 102
₁ ～102N address information necessary to read the first common file management information model stored in the area 101 (reserved sector count, sector length) to include the AD _1-ADn,
Each computer device reads the file management information common to the models using the address information. Further, position information of an area where the logical format information 102 _{1 to} 102 n of the computer device is recorded is recorded at a position on the storage medium 11 corresponding to each computer device. Then, when the storage medium 11 is mounted, the computer device (personal computer) reads the position information of the logical format information area from the position corresponding to the own device on the storage medium, and responds to the self from the area indicated by the position information. Read logical format information,
Based on the read logical format information, file management is performed by using file management information common to the models recorded in the first area 101. Also, the logical format information of the computer device is recorded at a position on the storage medium 11 corresponding to each computer device. Storage medium 11
Is attached, the computer device (personal computer) reads the logical format information corresponding to itself from the position on the storage medium corresponding to the device itself, and is recorded in the first area 101 based on the read logical format information. File management using the file management information common to all models.

[0018]

EXAMPLES diagram 2 of the system is a structural diagram of a system for the recording medium an optical disk, 11 optical disc (e.g., partial ROM),
21 is an optical disk drive, 31 is a host system (computer body), 41 is a data input unit (operation unit), and has a keyboard 41a and a mouse 41b.
51 is a display device such as a CRT or a liquid crystal display, and 61 is a printer. In addition, a hard disk device and a floppy disk device are provided as appropriate. The optical disk 11 has a plurality of sections, for example, a section (first section) 12 provided in a rewritable RAM area and a section (second section) 13 provided in a read-only ROM area.

FIG. 3 is an electrical configuration diagram of the system, and the same parts as those in FIG. 2 are denoted by the same reference numerals. 21 is an optical disk drive, 22 is a hard disk drive, 31 is a host system, 71a to 71b are I / O controllers, and 72 is a SCSI (Small Computer System Interface).
e: SCSI) bus. SCSI is an interface that connects the computer and external storage devices.
American National Standard Institute). The SCSI bus includes, for example, a data bus composed of 8 bits and parity bits and 9 control buses. Up to eight SCSI devices (host computer, disk drive controller, etc.) can be connected to this SCSI bus, and each device has an ID.
It has an identification number from 0 to 7 called (Identifier). In the figure, IDs are assigned to the I / O controllers 71a to 71b.
0 to ID1 are assigned, and the ID is assigned to the host system 31.
7 is assigned. I / O controller 71a-
Although one optical disk drive 21 and one hard disk drive 22 are connected to 71b, two or more drives can be connected.

In the host system 31, 31a is a central processing unit (processor), 31b is a memory (main storage device), 31c is a DMA controller, and 31d is a host controller.
The adapters 71c to 71d are I / O controllers, and each unit is connected to the host bus 31e. Reference numeral 23 denotes a floppy disk drive, and an I / O controller 71
c. 41 is an operation unit, 51 is a display device,
Reference numeral 61 denotes a printer, and each of the I / O controllers 7
1d. The host system 31 and the I / O controllers 71a to 71b are connected by a SCSI interface, and the I / O controllers 71a to 71b and the drives 21 and 22 are connected by, for example, an ESDI interface (Enhanced Small Device Interface). ing. In this system, the optical disk drive 21 and the hard disk drive 22 are separated from the host bus 31e,
A SCSI bus 72 is provided separately from the host bus.
I / O controllers 71a-7 for each drive on the I bus
1b, the drives 21 and 22 are controlled by the I / O controllers 71a and 71b to reduce the load on the host bus.

First Embodiment / Structure of Optical Disk FIG. 4 is a structural diagram of an accessible area in an optical disk which is a replaceable recording medium. Although only one section is shown, a plurality of sections can be provided. 11 'is an accessible area of the optical disk, 101 is a shared data storage area (first area) for storing shared data (FAT, directory, file) which can be accessed by personal computers of each company, and stores files shared by each personal computer. And a file management information area shared by each personal computer and storing file management information (FAT1, FAT2, directory) for managing the file. 1
A second area 02 records a plurality of types of logical format information for managing data recorded in the first area. The logical format information includes information (BPB table) necessary for the personal computer to access the shared file using the shared file management information, and a partition management table indicating the position of the BPB table. L of the second area 102
The BN2 is provided with a section management table 102a for company A so as to correspond to the personal computer for company A. The position information (LBN = 512) of the BPB table 102a 'is entered in the partition management table 102a, and the BPB table 10a
2a 'is the start position of the first area 101 (LBN = 51).
6) Address information (reserved sector number, sector length) indicating A
Da is included.

That is, the BPB table 102a 'contains information shown in FIG. 5A, sector length SS = 2048 bytes, cluster length SC = 2 sectors, reserved sector number RS = 1 sector, FAT number FN = 2, route The number of directories RDE = 1024, the total number of sectors TS in the logical volume TS = 61816, the media descriptor = FA, the number of sectors per FAT = 32 sectors, and the like are described. Using the address information (the number of reserved sectors and the sector length), the head position (first
The FAT head position is determined by the following equation: FAT head position = BPB table position + reserved sector number / sector length / 512 (1). Therefore, substituting the sector length = 2048 and the number of reserved sectors = 1 into the above equation gives the FAT head position = 516.

In the LBN 1 of the second area 102, a section management table 102b of company B is provided so as to correspond to the personal computer of company B. The partition management table 102b includes B
Position information of the PB table 102b '(LBN = 514)
Is entered, and the first area 1 is entered in the BPB table 102b '.
Address information (reserved sector number, sector length) ADb indicating the start position of L.01 (LBN = 516) is included. 5B, the sector length SS = 1024 bytes, the cluster length SC = 4 sectors, the number of reserved sectors RS = 1, the number of FATs FN = 2, and the entry of the root directory in the BPB table 102b '. The number RDE = 1024, the total number of sectors TS in the logical volume TS = 123631, the media descriptor = FA, the number of sectors per FAT = 64 sectors, and the like are described. Using the address information (the number of reserved sectors and the sector length), the head position (first
From the expression (1), FAT head position = 5
16 is obtained.

In the LBN0 of the second area 102, a section management table 102c of company C is provided so as to correspond to the personal computer of company C. This partition management table 102c includes B
Position information of the PB table 102c '(LBN = 515)
Is written, and the BPB 102c 'includes address information (reserved sector number, sector length) ADc indicating the head position (LBN = 516) of the first area 101. That is,
The BPB table 102c 'has information shown in FIG. 5C, sector length SS = 512 bytes, cluster length SC = 8 sectors, reserved sector number RS = 1 sector, FAT number FN = 2, and root directory entry number RDE. = 1024, total number of sectors in the logical volume TS = 247261, media descriptor = FA, number of sectors per FAT = 128 sectors, and the like. Using the address information (the number of reserved sectors and the sector length), the head position (first
From the expression (1), FAT head position = 5
16 is obtained. Partition management table 10 of each company's personal computer
2a to 102c are recorded in advance at positions (known) that are read by the personal computers of the respective companies when the disc is inserted.

File access control When a personal computer of each company reads a file, the file is accessed as follows. In the case of Company A's personal computer The optical disk is the optical disk drive 21 of Company A's personal computer.
2 and 3, since the host system 31 of the personal computer of the company A recognizes that the partition management table exists in the LBN2, the host system 31 automatically reads the partition management table 102a from the LBN2. Section management table 10
2a is the position of the BPB table of Company A (LBN512)
Is entered, the host system is LBN512
Then, the BPB table 102a 'of Company A is read. Then, the first area 101 is obtained from the address information (reserved sector number, sector length) ADa included in the BPB table 102a '.
Starts from LBN516. Thereafter, the host system reads the designated file from the first area using the FAT information and the directory information, or writes the file to the first area. When a file access to another partition is instructed during the operation of the system, the host system refers to the partition management information 102a to grasp the position of the BPB table of the partition, and designates the location by referring to the BPB table. To access the files in the partition that was created.

In the case of the company B personal computer The optical disk is loaded into the optical disk drive 21 of the company B personal computer.
2 and 3, since the host system 31 of the personal computer of Company B recognizes that the partition management table exists in the LBN1, it reads the partition management table 102b from the LBN1. Since the BPB table recording position of company B (LBN 514) is entered in the partition management table 102b, the host system
The company BPB table 102b 'is read. Then B
From the address information (reserved sector number, sector length) ADb included in the PB table 102 ', the first area 101
It recognizes that it starts with 516. Thereafter, the host system reads the designated file from the first area using the FAT information and the directory information, or writes the file to the first area. When a file access to another partition is instructed during the operation of the system, the host system refers to the partition management table 102b to grasp the position of the BPB table of the partition, and specifies the BPB table by referring to the BPB table. To access the files in the partition that was created.

In the case of the personal computer of Company C, the optical disk is loaded into the optical disk drive 21 of the personal computer of Company C.
2 and 3, since the host system 31 of the personal computer of the company C recognizes that the partition management table exists in LBN0, it reads the partition management table 102c from LBN0. Since the recording position (LBN 515) of the BPB table of Company C is entered in the partition management table 102c, the host system LBN 515
The BPB table 102c 'of the company is read. Then B
Address information ADc included in PB table 102c '
It is recognized that the first area 101 starts from the LBN 516. Thereafter, the host system reads the designated file from the first area using the FAT information and the directory information, or writes the file to the first area. When a file access of another partition is instructed during the system operation, the host system refers to the partition management table 102c to grasp the position of the BPB table of the partition, and
Access the file in the specified partition by referring to the table. In this manner, one optical disk can be used in common by a plurality of types of computer devices, and data recorded on the optical disk can be commonly used by a plurality of types of computer devices. be able to.

FIG. 4 shows a section management table 1 corresponding to each company's personal computer.
In this case, the partition management tables 02a, 102b, and 102c are provided. However, as shown in FIG. 6, there is a case where the partition management table does not exist (the partition management table of the company C does not exist). In FIG. 6, reference numeral 11 'denotes an accessible area of the optical disk, and 101 denotes a shared data storage area (first area) for storing shared data (FAT, directory, file) accessible by personal computers of the respective companies. And a file management information area which is shared by the personal computers and stores file management information (FAT1, FAT2, directory) for managing the file. Reference numeral 102 denotes a second area for recording a plurality of types of logical format information for managing data recorded in the first area. LB of the second area 102
N1 is provided with a section management table 102a of company A so as to correspond to the personal computer of company A. The partition management table 102a has position information (LBN =
512) is entered, and the BPB table 102a 'includes address information (reserved sector number, sector length) ADa indicating the head position (LBN = 516) of the first area 101.

That is, the BPB table 102a 'contains information shown in FIG. 7A, sector length SS = 2048 bytes, cluster length SC = 2 sectors, reserved sector number RS = 1 sector, FAT number FN = 2, route The number of directories RDE = 1024, the total number of sectors TS in the logical volume TS = 61816, the media descriptor = FA, the number of sectors per FAT = 32 sectors, and the like are described. Using the address information (the number of reserved sectors and the sector length), the head position (first
FAT head position = 51 from equation (1)
6 is obtained.

In LBN0 of the second area 102, a partition management table 102b of company B is provided so as to correspond to the personal computer of company B. The partition management table 102b includes B
The position information (LBN = 515) of the PB table is entered, and the BPB table 102b 'includes address information ADb indicating the head position (LBN = 516) of the first area 101. That is, the information shown in FIG. 7B, the sector length SS = 512 bytes, the cluster length SC = 8 sectors, the number of reserved sectors RS = 1, the number of FATs FN = 2, and the entry of the root directory are shown in the BPB table 102b '. The number RDE = 1024, the total number of sectors in the logical volume TS = 247261, the media descriptor = FA, the number of sectors per FAT = 128 sectors, and the like are described. Using the address information (the number of reserved sectors and the sector length), the head position (first
From the expression (1), FAT head position = 5
16 is obtained.

In the LBN0 of the second area 102, a BPB table 102 of Company C is further provided so as to correspond to a personal computer of Company C.
The BPB table 102c 'includes address information ADc indicating the head position (LBN = 516) of the shared data area 101. That is, BP
The B table 102c 'has information shown in FIG. 7C, sector length SS = 512 bytes, cluster length SC = 8 sectors, reserved sector number RS = 516 sectors, FAT number FN = 2, and root directory entry number RDE. = 1024, the total number of sectors in the logical volume TS = 247776, the media descriptor = FA, the number of sectors per FAT = 128 sectors, and the like. Using the address information (the number of reserved sectors and the sector length), the head position (first
From the expression (1), FAT head position = 5
16 is obtained.

Incidentally, the BPB table 102c 'of Company C is recorded in advance at a position (known) at which the PC of Company C first reads when the disc is inserted. In addition, the information of Company B and Company C of LBN0 is provided at a position where they do not overlap with each other. For this reason, LBN0 can have information on the companies B and C.
For example, the personal computer of Company C reads the BPB table from the position on the assumption that the BPB table is recorded in the 0th byte to the mth byte of LBN0, and the personal computer of Company B partitions the data from the nth byte (n> m) onward. The partition management table is read from the position assuming that the management table is stored. The personal computers of the companies A and B can access the file as in the case of FIG. In the case of a C company personal computer, when the optical disk is inserted into the optical disk drive of the C company personal computer, the host system sets BPB to LBN0.
Since it is recognized that the table exists, the LBN
The BPB table 102c 'is read from 0. Then
The address information ADc included in the BPB 102c 'recognizes that the first area 101 starts from the LBN 516. Thereafter, the host system reads the designated file from the first area using the FAT information and the directory information, or writes the file to the first area.

Second Embodiment of Optical Disc Configuration FIG. 8 is a block diagram of a second embodiment of an accessible area in an optical disc which is a replaceable recording medium. In this embodiment, only the computer device of the model registered in the model / logical format correspondence table described later (not limited to one).
Can use an optical disk. 11 'is an accessible area of the optical disk, 101 is a shared data storage area (first area) for storing shared data (FAT, directory, file) which can be accessed by personal computers of various companies, 10
Reference numeral 2 denotes a second area for recording a plurality of types of logical format information for managing data recorded in the first area; 103, a third area for recording a model / logical format correspondence table MFT; This is a fourth area for storing a model identification program MPR for performing the operation. The first area 101 is provided with first and second two FAT entries, directory entries, and file areas, and stores FAT information, directory information, and various files.

In the LBN 14 of the second area 102, the BPB table 102d 'of Company D is provided so as to correspond to the computer of Company D.
Is stored. As shown in FIG. 9 (a), the BPB table 102d 'of company D has a sector length SS = 512 bytes, a cluster length SC = 8 sectors, the number of reserved sectors RS = 25 sectors, the number of FATs FN = 2, and the root directory. The number of entries RDE = 1024, the total number of sectors TS in the logical volume TS = 246304, the media descriptor = FA, the number of sectors per FAT = 128 sectors, and the like are described.

The BPB table 102e 'of company E is stored in the LBN 15 of the second area 102 so as to correspond to the personal computer of company E.
Is stored. As shown in FIG. 9B, the BPB table 102e 'of Company E has a sector length SS = 2048 bytes, a cluster length SC = 2 sectors, a reserved sector number RS = 6 sectors, a FAT number FN = 2, and a root directory. The number of entries RDE = 1024, the total number of sectors TS in the logical volume TS = 61576, the media descriptor = FA, the number of sectors per FAT = 32 sectors, and the like are described.

In the LBN 17 of the second area 102, the BPB table 102f 'of the company F so as to correspond to the personal computer of the company F
Is stored. As shown in FIG. 9 (c), the BPB table 102f 'of Company F has a sector length SS = 512 bytes, a cluster length SC = 8 sectors, the number of reserved sectors RS = 22 sectors, the number of FATs FN = 2, and the root directory. The number of entries RDE = 1024, the total number of sectors TS in the logical volume TS = 246304, the media descriptor = FA, the number of sectors per FAT = 128 sectors, and the like are described.

As shown in FIG. 10, in the model / logical format correspondence table MFT stored in the third area 103, the logical model name and the BPB are added to the model name of the personal computer.
The storage location of the table is associated. This model
From the logical format correspondence table, B
The PB table 102d 'is recorded in the LBN 14, and the BPB table 102e' of the E company personal computer is
15 shows that the BPB table 102f 'of the personal computer of company F is similarly recorded in the LBN 17. The fourth area 104 stores a model identification program MPR for identifying the model of the computer device. When the optical disk is inserted into the disk drive, the host system automatically starts the model identification program MP.
Read R and execute the model identification program. The model identification program MPR is based on the model information of the personal computer (for example, Fujitsu F
MR80, NEC PC9801, etc.), and the position of the BPB table corresponding to the personal computer model is identified from the model / logical format correspondence table MFT. In addition, model information for identifying the model is always stored in the ROM of every personal computer.

Comparison of logical format of each company BPB table 102 of each company in FIGS. 9 (a) to 9 (c)
Referring to d ', 102e', and 102f ', the start position of the FAT is obtained by adding the reserved sector to the LBN in which the BPB table exists, and thus matches as follows. Company D FAT start position: LBN (14 + 25.1) =
LBN39 E Company FAT start position: LBN (15 + 6.4) =
LBN39 FAT head position of Company F: LBN (17 + 22.1) =
LBN39 The reason why the number of reserved sectors 6 is multiplied by 4 in calculating the FAT head position of Company E is that the size of one sector of Company E is four times the sector size of Companies D and F.
Also, the size of the FAT entry portion and the size of the root directory entry match when calculated in terms of sectors (= 512 bytes) as follows. Note that the size of one root directory entry is 32 as described with reference to FIG.
Bytes.

The size of the FAT entry portion The size of the FAT of Company D: 128 · 1 = 128 blocks The size of the FAT of Company E: 32.4 = 128 blocks The size of the FAT of Company F: 128 · 1 = 128 Block Size of root directory entry part Size of root directory entry part of Company D: 1024 · 32 (bytes) / 512 (bytes / sector)
= 64 blocks Size of company E's root directory entry: 1024 · 32 (bytes) / 512 (bytes / sector)
= 64 blocks Size of the root directory entry of Company F: 1024 · 32 (bytes) / 512 (bytes / sector)
= 64 blocks

Further, F in the logical format of each company
The AT start position, the root directory start position, and the file region start position match as shown in FIG. Here, the head position of the root directory entry part is FAT
At the head position, the size of FAT (FAT is the first and second 2
The file area head position is a value obtained by adding the size of the root directory entry part to the head position of the root directory entry part. As described above, each company's personal computer can point the FAT, the root directory entry, and the file area on the optical disc in common by the respective logical formats of the companies D, E, and F. That is, the personal computers of each company can use the first and second FATs recorded in LBN39 and LBN167 and later in common according to the logical format of each company, and commonly use the root directory recorded in LBN295 and later. As a result, the file area after the LBN 359 can be similarly accessed to read and write the file.

File Access Control FIG. 12 is a flow chart of a process at the time of disk access. A portion enclosed by a dotted line is a portion executed by the model identification program MPR. Optical disk drive 21 for personal computer
2 and 3 (step 201), the processor 31a of the host system 31 reads the model identification program MPR from LBN0 and stores it in the main storage device 31b (202). Thereafter, the processor executes the model identification program MPR (step 203). That is, the processor reads the model information of the personal computer recorded in the ROM (not shown) of the personal computer based on the model identification program (step 204).
With reference to the model / logical format correspondence table MFT recorded in N10, it is determined whether the read model name is registered in the table (step 205). If not registered, a message "Logical format not registered in disc" is displayed on display device 51 (step 206), and the process is terminated to wait for another optical disc to be inserted.

On the other hand, if the model name is registered in the model / logical format correspondence table MFT, the position of the BPB table is read from the table (step 20).
7). For example, in the case of company D's personal computer, LBN14 is read as the position of BPB table 102d ', in the case of company E's personal computer, LBN15 is read as the position of BPB table 102e', and in the case of company F's personal computer, BPB table 102f is read. The LBN 17 is read as the position of '. Thereafter, a predetermined BPB table is read (step 208). Thereafter, the file area is accessed using the FAT and the root directory recorded in the BPB table and the first area 101 to read and write the specified file (step 209). In this way, the model / logical format correspondence table MF
A single optical disk can be commonly used by a plurality of personal computers stored in T, and data registered in the optical disk can be commonly used.

In the above, when the model name is not registered in the model / logical format correspondence table MFT, a predetermined message is displayed (step 206), and after that, the file access processing is terminated. It can also be configured to execute. In such cases,
As shown in FIG. 13, the registration program C of the model / logical format correspondence table is stored in the fifth area 105 of the exchangeable recording medium.
Record the PR. FIG. 14 is a flowchart of the registration process by the registration program CPR. The processing in the model identification program MPR is shown in the dotted frame. Step 20 in FIG.
After step 6, a message as to whether or not to register the model is displayed on the display device 51 (step 210). In response to this message, if registration unnecessary is input, the file access processing ends (step 211). However, when a registration request is input, the CPU reads the registration program CPR from the optical disc and starts the registration program (step 212).

Thereafter, the processor 31a sequentially displays the input guidance messages on the display device 5 based on the registration program CPR.
1 (step 301), and the user inputs a model name (a personal computer of company G), a logical format name, and BPB information according to the guidance message (step 30).
2). The number of reserved sectors is determined by the system. Then, based on the logical format information of the company G, the BPB table storage position and the head position of the FAT entry part (LBN39), the head position of the directory entry part (LBN295), and the head position of the file area (LBN359) are obtained. Determine the number of reserved sectors (step 30)
3). If the BPB table storage position and the number of reserved sectors are obtained, the processor newly adds the model name, logical format name, and B of company G to the model / logical format correspondence table MFT.
The correspondence of the PB table position is added, and the BPB table of the company G is stored in the BPB table storage position (step 304), and the registration processing ends. As a result, the G company personal computer can use the optical disk.

Modified Example First Modified Example In the above description, only the BPB table is recorded as the logical format information. However, it is also possible to record both the partition management table and the BPB table as the logical format information. . FIG. 15 is a configuration diagram of an optical disc when both a section management table and a BPB table are recorded on an optical disc as logical format information, and includes a plurality of sections (first, second sections,...). 11 'is an accessible area of the optical disk, 101 ₁ ,
101 ₂ ... first, shared data in the second compartment ... first area for storing (FAT, directory, file), and 102 is recorded in the first area 101 _1, 101 ₂ ... A second area 103 for recording logical format information for managing data, a third area 103 for recording a model / logical format correspondence table MFT, and a model identification program MP 104 for identifying a model of a computer device.
This is a fourth area for storing R.

The first areas 101 ₁ , 101 _2, ... Have FAT entries (FAT entries) of the first and second sections, respectively.
1, FAT2), a directory entry, and a file area, and store first and second FAT information, directory information, and various files. In the second area 102, the section management tables 102d, 102e, 102
f and BPB tables 102 of the first and second sections of each company
d ', 102e', 102f '; 102d ", 102
e ", 102f" are stored. The section management tables 102d to 102f include the first sector (BPB table position) of each section as shown in FIG. BPB tables 102d 'to 102 for the first and second sections
f ', 102d "to 102f" are provided at the start of the first and second sections. The BPB table 10 of the first section
The contents of 2d 'to 102f' are the same as those in FIG.

The third area 103 stores a model / logical format correspondence table MFT '. As shown in FIG. 16, in the model / logical format correspondence table MFT ', the logical format name and the storage location of the partition management table are associated with the model name of the personal computer, and the partition management table 102d of the personal computer of company D is stored in the LBN 11. It is recorded that the partition management table 10 of the E company personal computer
2e is recorded in the LBN 12, and the partition management table 102f of the F company personal computer is recorded in the LBN 13.

When the optical disk is inserted into the optical disk drive 21 (FIGS. 2 and 3) of the personal computer, the host system 3
The first processor 31a reads the model identification program MPR from LBN0 and stores it in the main storage device 31b. Thereafter, the processor executes the model identification program MPR. The processor reads the model information of the personal computer recorded in the ROM of the personal computer based on the model identification program, and then refers to the model / logical format correspondence table MFT 'recorded in the LBN 10 and stores the read model name in the table. Is registered.
If not registered, a message "logical format not registered on disk" is displayed on display device 51, and the process is terminated to wait for another optical disk to be inserted. On the other hand, when the model name is registered in the model / logical format correspondence table MFT, the position of the partition management table is read from the table. Thereafter, the position of the BPB table of the first partition is read from the partition management table, and thereafter, the file area is accessed by accessing the file area using the FAT and the root directory recorded in the BPB table and the first area 101. To read and write.

Second Modification In the above, the model identification program is stored on the optical disc,
The case where the model of the personal computer is identified by executing the program has been described. However, if the personal computer has a function of identifying the model, it is not necessary to record the program on the optical disk. Third Modified Example The case where the present invention is applied to an optical disk has been described above. However, the present invention is not limited to an optical disk, but can be applied to a portable and replaceable storage medium such as an IC memory and a floppy disk. . As described above, the present invention has been described with reference to the embodiments. However, the present invention can be variously modified in accordance with the gist of the present invention described in the claims, and the present invention does not exclude these.

[0050]

As described above, according to the present invention, a file accessed by a plurality of computer devices (host systems) of different models, and file management information common to the plurality of computer devices of different models for managing the file. Is recorded in the first area, and the logical format information necessary for the computer device to manage the file using the common file management information of the model recorded in the first area is associated with each model of the computer device. Each computer device reads logical format information corresponding to its own model from the second area, and records the logical format information in the first area based on the read logical format information. The file can be managed using the file management information common to the models. In this case, position information of an area where the logical format information of the computer device is recorded is recorded at a position on a storage medium corresponding to each computer device. Then, when the storage medium is mounted, the computer device (personal computer) reads the position information of the logical format information area from a position corresponding to the own device on the storage medium, and responds to itself from the area indicated by the position information. The logical format information is read, and a first format is read based on the read logical format information.
The file management is performed using the file management information common to the models recorded in the area. Alternatively, the logical format information of the computer device is recorded at a position on a storage medium corresponding to each computer device. And
When the storage medium is mounted, the computer device (personal computer) reads the logical format information corresponding to itself from a position corresponding to the own device on the storage medium and records the logical format information in the first area based on the read logical format information. File management using the file management information common to all the models.

As described above, according to the present invention, one storage medium can be used in common by a plurality of types of computer devices (host systems), and the storage medium is recorded on the storage medium. The file that has been set can be used in common by a plurality of types of computer devices. Further, according to the present invention, each logical format information includes address information (reserved sector number, sector length) required to read model common file management information recorded in the first area, and each computer device Uses the address information to read the file management information common to the models, so that each computer device surely manages the file using the file management information common to the models recorded in the first area. Can be.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a system configuration diagram.

FIG. 3 is an electrical configuration diagram of the system.

FIG. 4 is a configuration diagram of a first embodiment of the optical disc of the present invention.

FIG. 5 is an explanatory diagram of a BPB table of each company.

FIG. 6 is an explanatory view of a modification of the first embodiment.

FIG. 7 is an explanatory diagram of each company's BPB table.

FIG. 8 is a configuration diagram of an optical disc according to a second embodiment of the present invention.

FIG. 9 is an explanatory diagram of a BPB table.

FIG. 10 is an explanatory diagram of a model / logical format correspondence table.

FIG. 11 is an explanatory diagram of position information in each format.

FIG. 12 is a flowchart at the time of file access.

FIG. 13 is a configuration diagram of an optical disc having a registration function.

FIG. 14 is a flowchart of a registration process.

FIG. 15 is an explanatory view of a modification of the second embodiment of the present invention.

FIG. 16 is an explanatory diagram of a model / logical format correspondence table.

FIG. 17 is an explanatory diagram of a ROM disk.

FIG. 18 is an explanatory diagram of writing / reading of a magneto-optical disk.

FIG. 19 is a diagram illustrating the configuration of an optical disk.

FIG. 20 is a configuration diagram of an accessible area.

FIG. 21 is an explanatory diagram of a partition structure.

FIG. 22 is an explanatory diagram of a directory structure.

FIG. 23 is an explanatory diagram of file management.

FIG. 24 is an explanatory diagram of file access of a personal computer using an optical disk as a recording medium.

FIG. 25 is an explanatory diagram of a logical format of each company.

[Explanation of symbols]

11. Exchangeable recording medium such as optical disk 101 First area for recording file and file management information 102 Second for recording plural types of logical format information
Area 102 ₁ ... First logical format information 102 ₂ ... Second logical format information 102 n... N-th logical format information AD _{1 to} AD n.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G06F 3/06 G06F 12/00 520

Claims (6)

(57) [Claims] 1. A file shared by a plurality of host systems, file management information shared by the plurality of host systems and managing the file, and each host system stores the file using the file management information. A storage medium control method for recording logical format information corresponding to each of the host systems required for accessing, a step of acquiring logical format information corresponding to the host system accessing the storage medium; and Accessing the file using the file management information with the logical format information corresponding to the above. 2. A file shared by a plurality of host systems, file management information shared by the plurality of host systems and managing the file, and each host system stores the file using the file management information. In a storage medium control method for recording logical format information corresponding to each of the host systems required for access and position information of the logical format information at a position corresponding to each host system, the host system corresponds to itself. Acquiring position information of logical format information corresponding to the host system from the position on the storage medium obtained; acquiring logical format information corresponding to the host system from the storage medium based on the position information; Logical format compatible with the system Accessing the file using the file management information based on information. 3. A file shared by a plurality of host systems, file management information shared by the plurality of host systems and managing the file, and each of the host systems at a location corresponding to each of the host systems. In a storage medium control method for recording logical format information corresponding to each of the host systems required to access the file using information, the host system determines the position of the storage medium corresponding to itself.
Obtaining at least logical format information corresponding to the host system; and accessing the file using the file management information based on the logical format information corresponding to the host system. Media control method. 4. The storage medium control method according to claim 2 , wherein the position corresponding to each host system is a position recognized by each host system. 5. The storage medium control method according to claim 2 , wherein the position corresponding to each host system is a position where each host system first reads information from the storage medium. 6. The logical format information includes address information necessary for reading the file management information, and further comprising reading the file management information of the storage medium using the address information.
The control method for a storage medium according to claim 2 or 3 .