JPS63257847A - File management system - Google Patents

Abstract

PURPOSE:To effectively use a main storage memory while utilizing the advantage of the memory sufficiently by allowing a control program to manage the main storage memory so as to relieve the load of application programs. CONSTITUTION:A file is placed on a main storage memory 2 as shown in figure and files 10-13 are assigned to always consecutive areas by the management of the control program (os) in the system ROM 4. In case the program file, since the program on the file is executed directly by a CPU 1, the program is executed directly. Then in order to relieve the load of the OS, the deletion of the program file is inhibited during the execution of program and the program file is placed at a lower-order address than that of the data file without fail by the management of the OS, then the program file is not moved during the execution of program. Thus, the load of the OS is relieved and the execution speed of the program is increased.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention is useful for storing data and application programs in a portable data terminal device that does not have an external storage device such as a floppy disk device. It relates to a management method for managing files as files under the control of a control program (hereinafter abbreviated as O8) when storing them on a storage memory.

[Explanation of conventional technology and its problems]

In conventional portable data terminal devices, there was no concept of storing data and programs stored in the main memory as files under the management of the O8. For this reason, the management of the main memory is left to the application program, which has many disadvantages, such as the application program becoming complex and the ability to respond flexibly to changes in memory capacity. Furthermore, even if the file management system used on conventional floppy disk devices were applied directly to the main memory of a data terminal device, the advantages of the main memory could not be fully utilized.

Figure 1 is a conceptual diagram of how to use conventional main memory.
There was no particular concept of memory management.

FIG. 2 is an example of a file management method carried out on a floppy disk device, in which entry addresses indicating data blocks allocated to each file in a file allocation table are shown from a directory corresponding to each file. Each entry in the file allocation table has a one-to-one correspondence with a data block, and successively points to a data block allocated to that file. In this way, the data areas allocated to a certain file are not necessarily continuous. On a floppy disk, there was no particular problem since the data was once loaded into the main memory of the data terminal device and processed, but this concept was not suitable for applying to file management in the main memory of the data terminal device. be. For example, main memory is the CPU
In the case of program files, etc., it can be directly executed on data blocks. However, in this case, the data blocks are not necessarily consecutive in main memory, so it is necessary to check each time whether the next instruction fetch address fits within the data block, which increases system overhead and The advantages of memory cannot be fully utilized.

[Means (and effects) for solving the problem] The present invention eliminates the above-mentioned drawbacks and allows O8 to manage the main memory, thereby lightening the load on application programs and simplifying the program. It has also become possible to take full advantage of the advantages of storage memory and use main memory effectively.

〔Example〕

FIG. 3 shows an example of the configuration of a portable data terminal device according to the present invention, which is the configuration of an extremely common computer. 1
is a CPU, 2 is a main memory, 3 is a memory back as an auxiliary memory, 4 is a system ROM in which a control program (OS) is placed, 5 is a keyboard, 6 is a display, and 7 is a power control circuit. , 8 is a battery which is a power source.

Figure 4 is an example of the concept of file management according to the present invention.
, 9 is a pointer that is a management table) IJ, 10.11 is a file for storing programs, 12.13 is a file for storing data, and 14 is an unused free area.

Files 10 to 13 are managed by O8 so that they are always allocated to consecutive memory areas. FIG. 5 is a diagram showing an example of a memory management method. The directory section manages the start address and size of each file.

In the example of FIG. 5, file 2 is deleted, and when data is added to file 2, another file (file 3 in the example of FIG. 5) is moved.

In the present invention, files are placed on the main memory and managed so that they are always allocated to a contiguous memory area, so in the case of a program file, it is possible to directly execute the program on that file from the CPU. Execute directly. However, when the program erases a file, and the file to be erased is at a lower address than the program file being executed, the file is moved by O8, and the program being executed is also moved.

In this case, OiS must check whether the file to be moved is a program file that is being executed, and if so, change the execution address, increasing the load on O8. Therefore, if the O8 manages files so that deletion of program files is prohibited while the program is running, and program files are always placed at lower addresses than data files, then the program file being executed cannot be moved while the program is running. Nothing will happen. Furthermore, it is necessary to erase copied programs only during program development and system setup, and there is no disadvantage to prohibiting the erasure of program files while the program is running.

In the example shown in Figure 5, only one directory section is set at the beginning of the memory for file management, but this is set at the beginning of each file as a header, and each header can be accessed in turn with a pointer. A method (Fig. 6) can also be considered.

〔Effect of the invention〕

As explained above, when data and programs are stored in the main memory of a data terminal device, they are managed as files, the area is allocated contiguously, and the program file is placed on the lower address side of the remote than the data file. By managing the program files so that they are positioned in the correct position, and by prohibiting deletion of the program files while the program is running, the program on the program file can be executed directly on the CPU, and the movement of program files is also eliminated. The load on O8 is reduced and the program execution speed is improved.

[Brief explanation of the drawing]

Figure 1 is a conceptual diagram of memory management in a conventional data terminal device.
FIG. 2 is a diagram showing an example of a file management method in a floppy disk device, FIG. 3 is a diagram showing an example of the configuration of a data terminal device according to the present invention, and FIG. 4 is a diagram showing an example of the concept of file management according to the present invention. 5 is a diagram showing a file management method according to the present invention, and FIG. 6 is a diagram showing another example of the concept of file management according to the present invention. 1... CPU 2... Main memory 3... Memory pack 4... System ROM 5... Keyboard 6... Display 7... Power control circuit 8... Battery 9... Directory part 10.11...Program file 12.13...Data file 14...Free space

Claims (1)

[Claims] In a data terminal device that does not have an external storage device, when data and programs are stored in a continuous area in the form of files on the main storage device, the files are classified into data files and program files. , a file management method characterized by locating program files at lower addresses than data files.