JPH0393059A - Magneto-optical disk operating system - Google Patents

Abstract

PURPOSE:To improve the performance of a data processing system by adding information showing the erasing state of a record area to link information by record areas in a file allocated table. CONSTITUTION:In the case of a write instruction except for initial writing into a magneto-optical disk, erasing information 4 in pointers with erasing information 20-22 in the file allocated table (FAT) 1 is referred, and erased record area is searched, writing is executed, and the bit of erasing information 4 as to the area concerned is set to be '1'. At the time of erasing a file, 7FFFH is written into a pointer area 2 corresponding to the file concerned. When the bit of erasing information 4 is in a non-erasing state '1' and the pointer 2 is 7FFFH, erasing is executed in the record area concerned. Consequently, an erasing processing immediately before writing when the write instruction is generated can be omitted and the performance of the data processing system can be improved.

Description

[Detailed description of the invention] [Industrial application field]

The present invention is intended to enable writing to a magneto-optical disk that cannot be overwritten (that is, writing data without erasing) without degrading the performance of a data processing system as much as possible. Relating to an operating system for magneto-optical disks.

[Conventional technology]

Magneto-optical disks currently in use cannot be overwritten, so they must be in an erased state when writing data. By the way, conventional file operating systems (such as MS-003.υNlχ) are intended for overwritable magnetic disk drives, so when writing data, erase processing is performed on the magneto-optical disk drive. By making sure to perform the write operation before writing, it is possible to operate under a conventional operating system.

[Problem to be solved by the invention]

However, in a magneto-optical disk drive system using such an operating system, two rotations are always required when writing data: one rotation for erasing and one rotation for data writing. This is a factor that significantly lowers the performance of data processing systems compared to fixed disks, and together with the problem that the seek time is longer than fixed data, this is a major problem with magneto-optical disk devices. In order to solve these problems, development is currently underway to enable overwriting on the magneto-optical disk device side, but this is still technically difficult. Therefore, the present invention provides a magneto-optical disk operating system that can reduce the erase processing time during writing as much as possible in a system using a magneto-optical disk device that is not overwritable, thereby obtaining a data processing system with higher performance. By doing so,
The objective is to solve the above problem.

[Means for Solving the Problems] In order to solve the above problems, the operating system of the present invention provides link information (pointer 2, etc.) for each record area in the file allocated table (1, etc.) of the magneto-optical disk. information (such as 4, hereinafter referred to as erase information) indicating the erase state of the corresponding record area is added to each, and the erase information is referred to when writing to the magneto-optical disk except for the first write. 1 to write to the erased record area, or to erase the deleted record area before a new write command is issued to the magneto-optical disk. shall be set to 1.

[For use]

File allocated table (hereinafter referred to as FA) is a table for knowing the file arrangement of magneto-optical disks.
Information that can identify the erase status of each record area is added to the pointer as link information between record areas (also abbreviated as T), and except for the first write, the erase status is determined by looking at this erase status identification information. By writing to the record area located in the record area, the erase process immediately before writing when a write command is generated can be omitted. Furthermore, an erase area is secured by performing an erase process on the deleted file before a write command is issued.

【Example】

FIG. 1 shows a file allocated table (FA
An example of the structure of T) is shown below. In the same figure, l is FAT,
3 (30, 31, 32.-.) are pointers with erase information provided corresponding to the record areas as write unit areas in the magneto-optical disk, respectively, and pointers 2 (20, 21. 22.-) and erase information 4. Here, pointer 2 is link information between record areas, specifically the pointer number of the next record area to be linked to the record area. That is, in FIG. 1, assuming that the record areas corresponding to pointers 20, 21, and 22 are connected in order to form one file, the number of pointer 21 is written in pointer 20, and The number of the pointer 22 is written in the pointer 2l. Erase information 4 is information added in the present invention,
This is information indicating whether or not the corresponding record area is in an erased state. For example, in MS-DOS, the pointer is 1.5 bytes (
12 bits), so on a magneto-optical disk, it is only necessary to represent at most 10 times as much area as a pointer.In Figure 1, if we use 15 bits for pointer 2 and 1 bit for erase information 4, a total of 16 bits. Enough. The bit definition of erase information 4 is “l” for non-erased state, “0”
” is in the erased state. In the case of a write command other than the first write, use the above erase information 4 to find the erased record area and write there. Set the erase information 4 bit for the area to “1”. Next, when deleting a file, write 7FFFH to the pointer area 2 corresponding to the file. Then, set the erase information 4 bit to “1”. Bit is “l”
), and the pointer 2 is 7FFFH, the corresponding record area is erased. This erase process is performed manually or automatically when deleting or in an idle state after deleting.

【Effect of the invention】

According to the present invention, the erase information 4 indicating the erase state of each record area is added to the pointer 2 as link information for each record area in the file allocated table (FAT) l of the magneto-optical disk, and When writing other than the first write to the magneto-optical disk, refer to the erase information 4 and write to the erased record area, or write to the deleted record area. Since the erase process is performed before a new write command is issued to the magneto-optical disk, a performance amplifier for data processing systems can be realized without overwriting. FAT. The performance can be brought closer to that of a fixed disk by writing to 1 after a series of processing. File processing such as UPDATE (i.e., writing by erasing the entire area of the magneto-optical disk) often involves measurement equipment or human intervention, and this rarely occurs when compiling or editing files. Also, significant improvements in the performance of data processing systems are achieved by the present invention.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the structure of a file allocated table (FAT) as an embodiment of the present invention.

Claims (1)

[Scope of Claims] 1) Information indicating the erase state of each record area (hereinafter referred to as erase information) is added to the link information for each record area in the file allocated table of the magneto-optical disk, and 1. A magneto-optical disk operating system characterized in that when writing other than the first write to a disk, the erase information is referred to and writing is performed to a record area in an erased state. 2) In the system according to claim 1,
A magneto-optical disk operating system characterized in that erase processing is performed on a deleted record area before a new write command is issued to the magneto-optical disk.