File management method for interchangeable storage media

A method of managing files of an interchangeable storage medium having a RAM area originally serving as a RAM section and a ROM area originally serving as a ROM section, each original section having a file management area for storing file management information and a file area for storing files, said file management information including directory information indicating correlation between file names and first cluster numbers of files, and a space-allocation management table which designates a file storage location by linkage of cluster numbers, said method comprising the steps of:

• entering a request for establishing a mixed RAM-ROM section, in which the RAM area and the ROM area are mixed, from said original RAM and ROM section;
• determining a starting position A of the file area of the original ROM section in the form of a logical block number;
• determining a difference D between the storage capacity of the mixed RAM-ROM section and the storage capacity of the original ROM section in the form of a logical block count;
• determining a position, which is offset from the file starting position A of the original ROM section by said difference D, which is expressed by the logical block count, as a file starting position B of the mixed RAM-ROM section;
• dividing the logical block count D between the file starting position A of the original ROM section and the file starting position B of the mixed RAM-ROM section by the number of blocks per cluster to determine an offset cluster count C between positions A and B;
• adding the offset cluster count C to cluster numbers of the directory information and the space-allocation management file, both of which are contained in the file management information of the original ROM section, to convert the file management information of the original ROM section to mixed RAM-ROM section file management information;
• writing said mixed RAM-ROM section file management information in a file management area of the mixed RAM-ROM section;
• writing the file management information of the original RAM section in the mixed RAM-ROM section file management area;
• and
• managing ROM files and RAM files as files of the mixed RAM-ROM section.

A method of managing files of an interchangeable storage medium comprising the steps of:

• inputting a request for converting an optical storage medium having RAM areas originally serving as RAM sections and a ROM area originally serving as a ROM section into a storage medium having a single mixed RAM-ROM section in which the entire RAM areas and the ROM area are mixed, each original section having a file management area for storing file management information and a file area for storing files;
• reading the file management information out of the file management area of the original ROM section in response to said request:
• converting the file management information of the ROM section into mixed RAM-ROM section file management information of a single mixed RAM-ROM section by making cluster numbers contained in the file management information of the original ROM section into cluster numbers of the single mixed RAM-ROM section;
• storing the mixed RAM-ROM section file management information in a single mixed RAM-ROM section file management area;
• storing RAM file management information originally recorded in said RAM area in the single mixed RAM-ROM section file management area as the mixed RAM-ROM section file management information;
• and
• managing ROM files and RAM files as files of the mixed RAM-ROM section based upon the mixed RAM-ROM section file management information.

A system for converting an optical storage medium having a RAM area originally serving as a RAM section and a ROM area originally serving as a ROM section into a storage medium having a mixed RAM-ROM section, each original section having a file management area for storing file management information and a file area for storing files, said system comprising:

• an optical disk drive for reading and writing information from said optical disk medium and for reading and writing information from and to re-writable portions of said optical disk medium;
• a host for controlling reading and writing of information by said disk drive, said host including means for:
• reading, using said disk drive, the file management information of the original ROM section;
• converting the file management information of the original ROM section to mixed RAM-ROM section file management information by making cluster numbers contained in the file management information of the original ROM section into cluster numbers of the mixed RAM-ROM section,
• writing, using said disk drive, the mixed RAM-ROM section file management information and the file management information of the RAM section in a mixed RAM-ROM section file management area;
• and
• managing ROM files and RAM files as files of the mixed RAM-ROM section.

A system for converting an interchangeable optical storage medium having a RAM area originally serving as a RAM section and a ROM area originally serving as a ROM section, each original section having a file management area for storing file management information and a file area for storing files, said file management information including directory information indicating correlation between file names and first cluster numbers of files, and a space-allocation management table which designates a file storage location by linkage of cluster numbers, said system comprising:

• an optical disk drive for reading and writing information from said optical disk medium and for writing information onto re-writable portions of said optical disk medium;
• a host for controlling reading and writing of information by said disk drive, said host including means for:
• reading, using said disk drive, the file management information of the original ROM section;
• converting the file management information of the original ROM section to mixed RAM-ROM section file management information by
• determining a starting position A of the file area of the original ROM section in the form of a logical block number;
• determining a difference D between the storage capacity of the mixed RAM-ROM section and the storage capacity of the original ROM section in the form of a logical block count;
• determining a position, which is offset from the file starting position A of the original ROM section by said difference D, which is expressed by the logical block count, as a file starting position B of the mixed RAM-ROM section;
• dividing the logical block count D between the file starting position A of the original ROM section and the file starting position B of the mixed RAM-ROM section by the number of blocks per cluster to determine an offset cluster count C between positions A and B;
• and
• adding the offset cluster count C to cluster numbers of the directory information and the space-allocation management file, both of which are contained in the file management information of the original ROM section, to convert the file management information of the original ROM section to mixed RAM-ROM section file management information;
• said host further including means for
• writing, using said disk drive, the mixed RAM-ROM section file management information and the file management information of the RAM section in a mixed RAM-ROM section file management area, and
• managing ROM files and RAM files as files of the mixed RAM-ROM section.

An interchangeable storage medium comprising:

• a mixed RAM-ROM section for storing both RAM and ROM files therein;
• and
• a mixed RAM-ROM section file management area for storing file management information concerning said RAM and ROM files stored in said mixed RAM-ROM section,
• wherein said file management information includes:
• a mixed RAM-ROM file directory;
• and
• a mixed RAM-ROM space allocation table, and
• wherein said file directory includes information indicating correlation between file names and first cluster numbers of files for both RAM and ROM files, and said space allocation table designates storage locations of files by linkage of cluster numbers for both RAM and ROM files.