JPH0664521B2 - Writable optical disk management method and system - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention allows an operating system to manage information recorded on a storage medium such as a writable optical disk in the same manner as information recorded on a read-only optical disk. The present invention relates to a management method of a writable storage medium that enables the above.

2. Description of the Related Art Optical discs having a capacity of several tens to several hundreds of times that of magnetic storage media have begun to be used as storage media for external storage devices of computers. However, at present, since write-once type and read-only type optical discs are mainly used, ordinary operating systems cannot manage optical discs by the same management method as rewritable magnetic media such as floppy disks and hard disks. Therefore, a file management system unique to the optical disk is required, and general commands such as file reading and directory display are dedicated to each management system, and the information and operation of the optical disk are not compatible. In recent years, in order to share data in a read-only optical disk, that is, data on the medium is processed by various information processing systems and operating systems (for example, MS-DOS (trademark of Microsoft Corporation) and UNIX).
4. A standard format and a management method for enabling use in a general-purpose operating system (OS developed by ATT) are being actively studied.
With respect to a 25-inch read-only optical disk (hereinafter referred to as a CD-ROM), the ISO discussed the logical format and standardized it as ISO9660 (reference: ISO9660, Apr.1988 “Volume and File Structer of
CD-ROM for Information Interchange ”).

However, writable optical discs have not yet been internationally standardized. In particular, in the case of the write-once type optical disk, unlike the case of a read-only type CD-ROM or a rewritable magnetic storage medium, a standard management method has not been established due to the special property of write-once. However, a writable optical disk is a replaceable portable storage medium like a floppy disk, and it is desirable that the writable optical disk be recorded by a standard storage method. There is an increasing demand for handling files in the same manner as files on recording media.

As a requirement for the optical disc management system, it is desirable to realize a data management system using a hierarchical directory in order to take advantage of the large capacity of the optical disc. For example, the above ISO9
660 realizes an efficient directory management system in consideration of the delay of the seek time of the CD-ROM. If the same directory type management method as that of a normal rewritable magnetic medium is used for an optical disc as it is, the optical disc is accessed each time a pointer to a subdirectory in the directory is searched for a file. Will be late. Therefore, the above-mentioned ISO966
In 0, each directory has a directory file that describes the file information and subdirectory information that belongs to that directory, and the directory management table (path information) that collectively records the location information of this directory file and the reference relationship between each directory. table)
have. The operating system that manages ISO9660 reads this path table into the memory and searches for a file, thereby reducing the number of times of accessing the optical disk and increasing the speed (reference: Nikkei Byte, August 1987). No., "Toward the utilization period of optical discs for personal computers: The de facto international standard for CD-ROM" High Sierra Format "").

SUMMARY OF THE INVENTION In view of the above problems in the present invention, the operating system sets information stored on a writable optical disc as information recorded in a standard format for a read-only optical disc. Similarly, if there is a mechanism for reading out a read-only optical disc recorded in the standard format, the data recorded on the writable optical disc can be written by any operating system or application on the system. The present invention provides a standard writable optical disc management method and system that can be used.

Means for Solving the Invention In order to achieve the above object, a writable optical disc management system of the present invention includes an optical disc for recording data and management information for managing the data on the same medium, and a read-only type. An operating system having a mechanism for managing data in an optical disc in file units, and read access in sector units performed by the operating system to a read-only optical disc by address change information in the writable optical disc It has a read control means having a read address changing mechanism for converting it into a read access to a sector, and an address change information rewriting mechanism for updating address change information in the read address changing mechanism in response to a write instruction in accordance with the write information. And a writing control means.

According to the invention, a mechanism for managing the read-only optical disc recorded in the standard format by emulating the read-only optical disc control unit for reading the read-only optical disc in accordance with the instruction from the operating system with the above configuration. It is possible to manage a writable optical disc from an operating system having a. In the above configuration as an emulation method, the read sector of the read-only type optical disk, which is read by the operating system having the mechanism for managing the read-only type optical disk, is writable by the read address changing mechanism of the read control means. The information recorded on the writable optical disc is changed by changing the read access to the corresponding sector of the Can be handled in the same manner as information recorded on a read-only optical disc.

Embodiments Embodiments of the writable optical disc management system of the present invention will be described below. FIG. 1 shows a configuration diagram of a writable optical disc management system, and FIGS. 2 to 6 are diagrams showing a configuration example of the write-once optical disc control unit in FIG. In this embodiment, a write-once optical disc will be used as the writable optical disc.

1 of FIG. 1 (embodiment of the invention described in claim 1) is an operating system (Operating System / hereinafter abbreviated as OS) 1 having a mechanism for managing a read-only optical disc, 1
Reference numeral 1 is a read-only optical disc management unit in the OS 1, 2 is a read instruction for a read-only optical disc, 3 is a write instruction for a write-once optical disc, 4 is a write-once optical disc control unit,
Reference numeral 5 is a read control means, 6 is a write control means, 7 is a write once read multiple (hereinafter abbreviated as WORM) optical disc and a schematic view of data arrangement thereof, and 8 is a read-only optical disc control part.

The read instruction 2 from the read-only optical disc management unit 11 is
The data is processed by the normal read-only optical disk control unit 8 and the data recorded on the read-only optical disk is read in accordance with the instruction. The write-once optical disc control unit 4 emulates the function of the read-only optical disc control unit 8 so that the read-only optical disc management unit 11 can store the WO.
The RM7 is treated as a read-only optical disc. Therefore, the read-only optical disc management unit 11 does not need to distinguish whether the read target is the read-only optical disc or the WORM. As a method of this emulation, the read control unit 5 uses the read-only optical disc management unit 11
The read control unit 6 has a read address changing mechanism for judging the designated address in response to the read instruction 2 and changing the read instruction to the corresponding address according to the address change information. The write control unit 6 adds or updates data. Read control unit 5
It has an address change information rewriting mechanism 60 for updating the address change information of the read address changing mechanism. The address change information is the correspondence between the data address in the management information (the read-only optical disc management unit 11 determines the data position based on this address and issues a read instruction) and the address at which the data is actually recorded. Is recorded.

FIG. 2 (embodiment of the invention according to claim 2) 51 is WORM.
Conversion of converting management information on WORM into management information of a predetermined format (e.g., path table of ISO9660, equivalent to volume descriptor) of the read-only type optical disk management unit 11 when exchanging 7 or starting the OS A transfer unit, 52 is an internal storage device that stores the management information transferred by the conversion transfer unit 51, and 53 is a read instruction 2 from the OS 1.
Is an access switching mechanism that switches to access to the WORM 7 or the internal storage device 52 according to the read address.

Since writing is not possible with a CD-ROM, there is no need to consider update processing. When the CD-ROM is created, management information such as a path table is sorted so that the OS can easily search it, and then mastered in a batch. But,
In the case of WORM, update processing such as addition of data occurs and rewriting into sorted management information is impossible.
Therefore, according to the present invention, when reading the management information, the management information of a predetermined format in the internal storage device 52 is read without directly reading the management information on the optical disk. At the time of the update processing, the management information in the internal storage device 52 is directly rewritten in a sorted form, and the information (history information) representing the rewriting content of this management information is recorded in WORM. The management information in the internal storage device 52 is
The management information is restored in the internal storage device 52 in a sorted form from the history information recorded on the optical disc.

When the management information is read again by placing the management information in the internal storage device 52 as shown in FIG.
It can be faster than reading from RM7.

511 in FIG. 3 (embodiment of the invention described in claim 3) is WO
A first conversion / transfer unit that converts management information on the WORM into intermediate management information and transfers the information when the RM is replaced or when the OS is initially activated.
2 is an internal storage device that stores the intermediate management information transferred by the first conversion transfer unit 511; 53 is an access switching mechanism that changes a read instruction from the OS 1 to access the WORM 7 or the internal storage device 52 according to the read address; 51
Reference numeral 2 is a second conversion transfer unit that re-converts the intermediate management information in the internal storage device 52 into management information in a predetermined format and transfers it when accessed by the access switching mechanism 53.

A read-only optical disc management unit 1 shown in FIGS. 1 to 3.
In No. 1, necessary management information such as a path table is buffered for high-speed processing. Since the write-once optical disc control unit 4 performs a process of rewriting the management information in the internal storage device 52 in the case of the recording process to the WORM 7, the OS
There may be a discrepancy between the buffered management information of 1 and the management information in the internal storage device 52 (details will be described later).

FIGS. 4 and 5 show a configuration diagram for invalidating (flushing) the buffered management information of the OS 1 in such a case.

110 in FIG. 4 (an embodiment of the invention according to claim 8) is O.
Reference numeral 31 is a management information storage buffer in S1, and reference numeral 31 is an interrupt for instructing flushing of the management information storage buffer 110. The OS 1 receives the interrupt 31 and receives the buffer 110.
Performs internal processing to flush.

However, some OSs do not have a mechanism for accepting the interrupt 31. In such a case, a disk replacement flag may be provided as shown in FIG.

In FIG. 5 (another embodiment of the invention according to claim 8), 54 is a disk exchange flag for monitoring the rewriting of the path table in the internal storage device 52, and 21 is a media check instruction for confirming whether or not the optical disk has been exchanged. Is. The read-only optical disc management unit 11 confirms whether or not the optical disc has been exchanged by the media check instruction 21 as a pre-process for reading the optical disc. This is because the management information of the optical disc before the exchange read in the buffer is invalid after the optical disc is exchanged. Therefore, the rewriting of the management information in the internal storage device 52 is monitored by the disk replacement flag 54, and when the management information is rewritten, the disk replacement flag 54 is turned ON and the optical disk is replaced when the media check instruction 21 is issued. If the flag is returned, the OS1 invalidates (flashes) the buffer and issues a new instruction to read the management information (in this case, the management information in the internal storage device 52 is only rewritten and the optical disk is actually replaced). Not).

In the following description, as an example of the reproduction-only optical disc management system, the reproduction-only optical disc management unit 11 is set to ISO96.
A case of managing a read-only optical disc in which data is recorded in the format defined by 60 will be described.
(The embodiment of the invention described in claim 6, the directory management table corresponds to a path table). MS- as OS1
DOS, MS CD-as read-only optical disc management unit 11
EXTENSION (Microsoft MS for ISO9660
A configuration using a DOS version extended file system) is possible, and the write-once optical disc control unit 4 is a basic input / output system (BIO) of the MS-DOS.
Equivalent to S). The optical disk drive device is not shown here.

FIG. 6a is a diagram in which the data arrangement in the WORM 7 of FIG. 5 is described in detail, and FIG. 6b is a diagram in which the reading process of FIG. 6a is explained in more detail.

In the format defined by ISO9660, CD-
A volume information 81, a path table 82, a directory file 83, and a data file 84 are recorded in the ROM. The volume information 81 is composed of a volume descriptor that records special information for the system, a volume identifier, a position of a path table, and the like. Fig. 6 a85 is C
In addition to the contents of the volume information 81 of the D-ROM, WOR
Volume information that additionally records initial setting information for M7,
86 is a path table information for recording a path table and its history information, 87 is a directory file, and 88 is a data file. The volume information 85 and the path table information 86 correspond to the management information in FIG. The directory file 87 and the data file 88 are recorded in the format defined by ISO9660. 6b, 520 is a volume descriptor (hereinafter abbreviated as VD) restored in a sorted form in the internal storage device 52, a path table (hereinafter abbreviated as PT), and 521 is a directory file address conversion table (hereinafter abbreviated). , DFT).

Prior to the description of FIGS. 6a and 6b, the configuration of the directory file and PT, which are the management information of ISO9660, and the update example thereof will be described first with reference to FIGS. 7 to 11. Here, the DFT shown in FIGS. 7e, 8e, and 10 is introduced in this embodiment as an example for the write-once type optical disc control section 4 to emulate the read-only type optical disc control section 8a. , ISO 9660, but an update example will also be described.

FIG. 7A is an example of a case where data management of a directory structure is performed. ROOT / AAA / BBB / CCCCC and AK are directory files (hereinafter, referred to as D).
(Abbreviated as F). FILE1 and FILE2 are files stored in the directory E, and FILE3 is a file stored in the directory BBB. Here, files stored in directories other than E and BBB are not shown.
FIGS. 7b and 7c are examples of the DF of the directory BBB and its subdirectory E when the directory structure of FIG. 7a is provided. D specified by ISO9660
F records the entry to the file and directory referred to in the corresponding directory, respectively. Each entry is management information that records a file name, a directory name, a recording position, a file size, and the like. For example, FIG. 7c
In the directory file of E, 701 is an entry to itself (DF of the directory E), 702 is an entry to the parent directory BBB, 703 and 704 are entries to FILE1 and FILE2 stored in the directory E, and 705 and 706 are It is an entry for the subdirectories J and K.

FIG. 7d is a schematic diagram of a path table defined by ISO9660. The path table is a directory management table that collectively records reference relationships between directories, and the parent directory number and other information are recorded according to the directory name / directory file recording position and the directory number assigned to the directory (subscript in FIG. 7a). To record. A unique number is preferentially assigned to the directory number from the upper hierarchy. In FIG. 7A, 770 is the byte length of the directory name, 771 is the DF address (recorded by a virtual address described later), 772 is the parent directory number, and 77.
3 is a directory name.

FIG. 7e shows an example of the DFT used in this embodiment. Reference numeral 707 is a virtual address and 708 is a real address. (Because 707 can be calculated by the relative position from the start position, it is not necessary to actually record it.) For example, BBB
DF's virtual address is LBN102 and is actually W
This indicates that the data is recorded in the real address LBNk on the ORM7. (The OS extension unit 11 reads the data on the CD-ROM in block units, and the read instruction 2 in block units is the logical address (Lo
gical block number (LBN) number is used as a key. Hereinafter, for example, the address of the m-th logical block is described as LBNm. ) FIG. 8a shows the directory structure when the subdirectory DD is created in the directory BBB of FIG. 7a. In this case, an entry to the newly created directory DD is added to the DF of the parent directory BBB to change it as shown in FIG. 8b, and a record of the bus table DD (dotted part in FIG. 8d) is added. It is necessary to perform the processing. Since the WORM cannot be rewritten, the DF of the replaced BBB is newly recorded in the WORM as shown in FIG. 8B to update the DF of the BBB. At this time, the real address for identifying the recording position in WORM changes (corresponding to the Real Address in FIG. 6B, the optical disk drive device can uniquely identify the block in WORM). In FIG. 6b, the real address of the BBB DF changes from LBNk to LBNn.

In ISO9660, the parent directory or subdirectory of the directory to be updated records an entry (actual address in DF) to this directory. Therefore, D
When recording the logical address of F with this real address, when updating the DF of BBB as shown in FIG. 9a,
Parent directory ROOT and sub directories D, E, F
It is also necessary to update the DF of Even if the BBB directory file is recorded in the unused part of WORM and the real address of the DF of the BBB changes, the entry to the BBB in the parent or subdirectory will be the new BBB.
This is because the DF 72 (Fig. 8b, LBNn) of No. is not pointed, and the DF 70 before update (Fig. 7b, LBNk) is still pointed. As described above, in order to update one DF, the DFs of related directories must be updated one after another in a chained manner, which is a particularly large overhead in the case of a hierarchical structure having many related directories.

Therefore, in this embodiment, a virtual address is assigned to the DF, and the DFT 521 in which the correspondence between the virtual address and the real address is recorded is introduced (the embodiment of the invention according to claim 4 or 5). The DFT is a correspondence table indicating to which real address the DF indicated by the virtual address is recorded.

Since each directory points to the address of the related directory by the virtual address, even if the DF is updated and the real address changes, it is only necessary to rewrite the corresponding relationship in the DFT 521, and the DF of the related directory needs to be updated at all. There is no. For example, the DF of the directory BBB has a virtual address of LBN102,
Even when updating the BBB, the real address of DFT521 is set to L
It is only necessary to rewrite from BNk to LBNn. (Dots in Figure 8e). It is not necessary to update the entries to the BBB such as the parent directory ROOT and the sub directories D and E because they point to the LBN 102 (immutable).

In addition, the path table and DFT are updated by the internal storage device 5.
The path table and the DTF in 2 are directly rewritten by the writing control means 6, and the history information indicating the changed contents is recorded on the optical disc (the embodiment of the invention described in claim 9). Although it is possible to record the entire new path table in the WORM each time the path table or DFT is rewritten, since the capacity efficiency of the WORM is deteriorated, this can be improved by recording the history information having a small amount of information ( The history information is preferably WORM-recorded in consideration of the portability of WORM, but may be temporarily stored in the auxiliary storage device (embodiment of the present invention).

FIG. 10 shows updating of the DFT in the internal storage device 52, and FIG. 11 shows an example of updating the bus table. In FIG. 10, 96 is after adding the record of the directory DD to be created in the DFT of FIG. 7E (DF of the directory DD to be newly created).
Record the real address LBN (n-1) of the DD at the position of the virtual address LBN115 to be allocated to
Shows the updated DFT (Fig. 8e). 99 is DFT9
This is history information created when rewriting from 6 to DFT97. Reference numeral 990 denotes a BBB virtual address, and 991 denotes a real address, which indicates that the DF real address of the virtual address LBN 102 is changed to LBNn. WOR
This history information 99 is written in M7.

In FIG. 11, 90 is the path table before the change in FIG. 7d, 9
5 is a path table after the change in FIG. 8d. Reference numeral 91 is a first half portion of the path DD record insertion position of the directory DD, and 92 is a second half portion. For example, directory D
In the case of D, the second half 92 from the insertion position of the path table is shifted to the transfer destination which is the address of the insertion path table record, the bus table record is inserted, and the parent directory number of the directory whose parent directory number changes is set. It is only necessary to increment by 1 after the change start position. Therefore, the history information only needs to have the insertion path table code, the insertion position, the transfer destination, the transfer amount, the parent number change start position, etc. (thus, about several tens of bytes is sufficient for the history information. , WORM is normally recorded in units of physical sectors of several hundred bytes, so a virtual address or WOR to be assigned to the DF of the directory to be created next is created in an empty area other than the history information.
It is also effective to record area information indicating the start address of the unused position of M together.

In the case of file update, DF is updated by updating DF.
Real address changes, but DFT in internal storage device 52
Is updated and the history information thereof is only written to WORM7, and PT need not be changed.

Based on the above, the processing of the management system of the present invention will be described with reference to FIGS. FIGS. 6a and 6b are diagrams for explaining in detail the processing contents, the data arrangement example of the read control means 5, and WORM 7 with the same configuration as FIG. Fig. 6 a, b
The configuration of the management system is the most general configuration example that can be easily implemented on the OS.
Consider a D-ROM. In FIG. 6b, the thin solid line shows the flow of instructions and the thick solid line shows the flow of data to be read.

In the OS initialization process that is performed when the replaced WORM 7 is attached to the system or when the power is turned on, first, the reproduction-only optical disc management unit 11 (hereinafter, abbreviated as OS extension unit) controls the optical disc drive device (not shown). In order to cause the existing control program to perform the initialization process of the optical disk drive, the control program is instructed to perform the initialization process. The control program sends a read instruction 2 for the boot sector in which the initial setting information of the CD-ROM is recorded, to the read-only optical disc control unit 8.

Normally, when reading a CD-ROM,
Although the boot sector is simply read, the WORM read control means 5 also performs the following processing at the same time, so that the WO
Initialization for reading RM7 is performed. The WORM read control means 5 receives an instruction for initial setting processing from the OS extension unit 11, reads the volume information 85 of WORM, and
By grasping the protection information of the ORM, the area setting information, the area size, etc., the conversion transfer unit 51 uses the path table information and the history information in the WORM as the VD and PT formats and D of ISO9660.
It is restored to the FT and stored in the internal storage device 52. At this time, if the processing time of the path table restoration is slow or the capacity of the internal storage device 52 is insufficient, the intermediate information (for example, the path table restoration in the sector in which the history information is recorded is temporarily restored as shown in FIG. It is also possible to store only the parameters necessary for the above as a format extracted from the above).

Then, the OS extension unit 11 reads the management information (VD and PT) of the CD-ROM. If the initialization process of the CD-ROM is not specially performed, the initialization process (V
D, PT, DFT restoration processing) is performed.

Since ISO9660 specifies that VD is recorded from LBN16 (16th block), the OS extension unit 11 first issues a read instruction of LBN16 to read VD.

However, the read control means 5 assigns this LBN to the virtual address of the virtual read-only optical disk (the Virtual Ad in FIG. 6B).
dress: VLBN). (In FIG. 6b, the logical address handled by OS1 is VLB for convenience of explanation.
N, the logical address for identifying the recording position on the write-once optical disc is described as the real address (RLBN). In the access switching mechanism 53, at the time of initial setting, the determination condition of whether to access the internal storage device 52 or the WORM 7 from the volume information 85, that is, the recording address range for accessing the internal storage device 52 (FIGS. 6a and 6b). LBNO
To LBN (d-1)).

In the read instruction 2 for the LBNx from the OS enlarging unit 11 in FIG. 6A, in the case of the read-only type optical disc control unit 8, the designated LBNx is simply read.

On the other hand, in the write-once optical disc control unit 4, the access switching mechanism 53 temporarily receives the virtual address and reads the internal storage device 52 or the WORM 7. As shown in FIG. 6b, the read instruction 2 from the OS extension unit 11 causes the access switching mechanism 53 to access the management information addresses LBN0 to LBN0.
It is determined whether it is a read instruction to the LBN 99, a read instruction to the directory file addresses LBN100 to LBN (d-1), or a read instruction to the data address LBNd and thereafter. The access to the address of the management information is the management information in the internal recording device 52, and the access to the data is the LBNx on WORM.
The address corresponding to is read.

As shown in FIG. 6b, the read control means 4 causes the LBN 16
Is determined to be access to the management information, and the VD transferred to the internal storage device 52 at the time of initial setting of WORM is read. Furthermore, a read instruction for the PT is issued from the address of the PT recorded in this VD, the restored PT is also read in the internal storage device 52, is buffered in the management information storage buffer 110, and is stored in the file. The read setting is completed, and the process is returned to the OS1.

Next, let us consider a case where the file FILE3 under the directory BBB in FIG. 8B is read. File FI
The directory BBB storing LE3 is the OS extension unit 1
The PT in the management information storage buffer 110 is searched by 1 and a read instruction of the virtual address VLBN 102 of the DF of the BBB is issued. The access switching mechanism determines that the VLBN 102 is a read instruction for the sector of the DF, the DFT 521 converts the read instruction to the real address RLBNn, and then the DF of the BBB is read from the WORM 7.

In the OS extension unit 11, the DF of the read BBB is further added.
From the entry of FILE3 in the table, the storage position (denoted by VLBNm) and size of FILE3 is known, a read instruction of VIBNm is issued, and FILE3 is read. In addition, a media check instruction is issued as a preprocess for reading the file from the next time. In response to this media check instruction, the read control means 5 judges the disk replacement flag 54, and when the VD or PT in the internal storage device 52 is updated, the status of CD-ROM replacement (usually 1) is set. return. In the OS extension section 11, the CD-
It is determined that the ROM has been replaced, the VD and PT read in the management information storage buffer 110 are invalidated (flashed), and the initial setting process of the CD-ROM is performed again.

In the above read processing, the OS extension unit 11 does not need to know whether the object to be read is a CD-ROM or a WORM. Therefore, the OS extension unit 11 sets the WORM to ISO.
It can be read as a 9660 format CD-ROM.

Next, the writing process will be described. An example in which the directory DD is created from FIG. 7A and is changed to FIG. 8A will be described. In this case, as the writing process, the parent directory BBB is used.
WOR of the updated directory file (Fig. 8b)
Writing to M, PT in the internal storage device 52 (FIGS. 7a to 8a), rewriting of DFT (FIGS. 7e to 8e), and writing of history information to WORM are performed. At this time, when the PT in the internal storage device 52 is rewritten, it is necessary to turn on the disk exchange flag 54 and rewrite the VD in the internal storage device 52 when the PT size is changed. is there.

Since the OS expansion unit 11 which is a reproduction-only type optical disc management unit does not have a writing process function, it is necessary to create a mechanism for performing this writing process in the OS 1 or the writing control means 6.

In this embodiment, the method of restoring the path table from the history information to the internal storage device is described, but when the history information increases, the restoration processing time becomes slow. Therefore, there is also a method of backing up in the form of the path table restored in the internal storage device 52 when a certain number of pieces of history information are created or when WORM is replaced (claim 1).
Inventive Example 1). In this case, when the next path table is restored, the restoration processing may be performed starting from the backed up path table, and the processing speed can be increased.

In addition, as a method of effectively using the recording area of WORM7, a mapping table is provided for each real address shown in FIG. It is also possible to arrange the pages in order from the necessary page (claim 12).
Example of the invention described). For example, WORM7 in FIG. 6b.
In the data layout diagram of, the path table information (history information)
There is a fixed partition for recording DF and DF,
Since the history information and the number of times the DF is recorded vary greatly depending on the usage state of WORM such as the number of times the file or directory is updated, it may be possible that the number of partitions provided in advance is insufficient or the area becomes excessive. Therefore, such a situation can be prevented and the WORM recording area can be efficiently used by adopting a method of sequentially allocating partitions in the WORM from necessary pages by using the mapping table.

In the above embodiments, the ISO9660 format has been described as the CD-ROM format. In addition to this, as the format for the optical disc, a format in which the reference pointers between the DFs of the parent and sub directories are omitted from the ISO9660 format is proposed, and the present invention manages such a format other than ISO9660. It can also support the OS extension unit.

According to the present invention, it becomes possible to manage a writable optical disc from an operating system having a mechanism for managing a read-only optical disc recorded in a standard format. For this reason, a large amount of commercially available software that uses a read-only optical disc can be used without modification, and there are great expectations for expanding the field of application of the optical disc.

[Brief description of drawings]

FIG. 1 is a block diagram showing the basic configuration of a writable optical disc management system according to an embodiment of the present invention.
FIG. 5 to FIG. 5 are block diagrams of configuration examples in the write-once type optical disc management system write-once type optical disc control unit,
FIGS. 6a and 6b are block diagrams of a general configuration example of the present invention, and FIGS. 7 to 11 are explanatory diagrams of management information in the above embodiment. DESCRIPTION OF SYMBOLS 1 ... Operating system, 11 ... Reproduction-only optical disc management unit, 2 ... Read instruction, 3 ... Write instruction, 4 ... Write-once optical disc control unit, 5 ... Read control means, 51 ... Conversion transfer Reference numeral 52 ... Internal storage device, 53 ... Access switching mechanism, 54 ... Disk exchange flag, 6 ... Write control means, 7 ... Write-once optical disk, 8 ... Read-only optical disk control section.

Claims (14)

[Claims] 1. An optical disc in which data and management information for managing the data are recorded on the same medium, an operating system having a mechanism for managing data in the read-only optical disc in file units, and the operating system. Read control means having a read address changing mechanism for converting read access in block units to a read-only optical disk from a block to read access of a corresponding block in the writable optical disk, and the operating system. And a write control means having an address change information rewriting mechanism for changing the address change information in the read address changing mechanism according to the write information when writing is instructed to the writable optical disc. Writable optical disc management system. 2. A conversion transfer unit for converting the management information in the writable optical disk into the format of the management information in the read-only optical disk and transferring the management information, as a read address changing mechanism, and storing the management information. An internal storage device and an access switching mechanism, the address change information rewriting mechanism has a mechanism for changing management information in the internal storage device when a write instruction is issued, and the access switching mechanism is a data recording block from the operating system. 2. The writable type according to claim 1, wherein the data in the optical disk is read directly in the case of a read access to the management information, and the management information in the internal storage device is read in the case of a read access to the management information recording block. Optical disc management system. 3. The read control means, as a read address changing mechanism, stores a first conversion transfer section for converting management information in a writable optical disc into intermediate management information in an intermediate format and transferring the intermediate management information. An internal storage device, a second conversion transfer unit for converting the intermediate management information into a read-only optical disc format, and an access switching mechanism are provided, and the address change information rewriting mechanism stores the management information in the internal storage device at the time of a write instruction. The access switching mechanism has a mechanism for changing the data, and when the access switching mechanism is a read access to the data recording block from the operating system, the data in the optical disc is directly used, and when the access is a read access to the management information recording block, the second transfer unit is used. 2. The writable optical disc management system according to claim 1, wherein the converted management information is read out. 4. An optical disk for recording data and hierarchical directory information on the same medium, an operating system having a mechanism for managing data in the read-only optical disk in file units, and the operating system stores directory information in the directory information. Read control means having a directory information address conversion table for limiting the address range to be used to a certain range of logical addresses and converting a read instruction for the logical address range into a read instruction for a real address in which directory information is actually recorded. And a write control means for changing the real address in the conversion table to an address additionally written with the directory information in accordance with the update processing of the directory information. 5. Hierarchical directory information is provided as management information, the operating system limits the address range used for the directory information to a range of a certain logical address, and the read control means issues a read instruction to the logical address range. A directory which has a directory information address conversion table for converting a read instruction to a real address in which directory information is actually recorded, and the write control means updates the real address in the conversion table in accordance with the update processing of the directory information. 4. The writable optical disc management system according to claim 1, wherein the information is changed to an additionally written address. 6. The operating system is ISO966.
6. The writable optical disc management system according to claim 1, further comprising a mechanism for reading an optical disc recorded in a format defined by 0. 7. An operating system has a mechanism for managing data in a read-only optical disc into a hierarchical directory structure using directory information and a directory management table for managing the directory information, and is writable by a conversion transfer unit. 7. The writable optical disc management system according to claim 2, wherein the management information in the optical disc is converted into a format of the directory management table and transferred to an internal storage device. 8. The writing control means has means for invalidating the management information buffered in the operating system when the writing process on the writable optical disc is completed. The writable optical disc management system according to claim 1, 2, 3, 6, or 7. 9. An update of data or directory information, a directory management table, or a directory information address conversion table in a writable optical disc is added to the writable optical disc as history information indicating the contents of change, and conversion transfer is performed. 9. The writable optical disc management system according to claim 2, wherein the writable optical disc management system restores the data in an internal storage device. 10. A writable optical disc and an auxiliary storage device, wherein data or directory information in the writable optical disc, a directory management table, or a directory information address conversion table is updated to indicate history information. Is added in the auxiliary storage device as
9. The writable optical disc management system according to claim 2, wherein the writable optical disc management system restores the data in an internal storage device by a conversion transfer unit. 11. A directory information or directory management table or a directory information address conversion table,
3. When a certain change is made, it is recorded in the writable optical disc in the same format as the directory information or the directory management table or the directory information address conversion table in the internal storage device. ,
The writable optical disc management system according to 3, 4, 5, 6, 7, 8, 9 or 10. 12. The writing control means has a mapping table in which a page arrangement in a writable optical disc is recorded in page units in which a plurality of blocks are collected. 5. The writable optical disc management system described in 5, 9, or 10. 13. An operating system which uses an optical disk having data and management information for managing the data recorded on the same medium as an external memory and has a mechanism for managing the data in the read-only optical disk in file units. In a computer system having
Converting read access in block units from the operating system to the read-only optical disc to read access of a corresponding block in the writable optical disc by using address change information; and writing from the operating system. A writable disc management method including a step of changing address change information according to the write information when a write instruction is given to the optical disc. 14. An operating system which uses an optical disk in which data and management information for managing the data are stored on the same medium as an external memory and has a mechanism for managing the data in the read-only optical disk in file units. In a computer system having
A conversion transfer unit for converting the management information in the writable optical disk into the format of the management information in the read-only optical disk and transferring it; an internal storage device for storing this management information; and a read control unit having an access switching mechanism, In the case of a read access to a data recording block from the operating system by the access switching mechanism, the data in the optical disk is directly written to by a write control means for changing management information in the internal storage device in response to a write instruction. In addition, in the case of a read access to the management information recording block, the management information in the internal storage device is read out respectively.