JPS63126046A - Method for managing external storage device - Google Patents

Abstract

PURPOSE:To improve the using efficiency of an external storage device by storing corrected data in another dead area when the corrected data can not be stored in its original storing position, and if there is no dead area, condensing the storing state of the external storage device and then storing the corrected data in a formed dead area. CONSTITUTION:The storing positions of respective pages in a document file stored in the external storage device 11 are controlled by a page control table 12b and dead areas in the external storage device are controlled by a dead area control table 12c. Under said status, the data of one page at least read out from a data storing area 11a in the external storage device are corrected. When the corrected data can be stored in the original storing area position 11a, the corrected data are stored in the position 11a, and if there is no dead area to store the corrected data, the storing state of the external storage device is condensed and the corrected data are stored in a dead area 11b generated as the condensed result.

Description

DETAILED DESCRIPTION OF THE INVENTION - <Industrial Application Field> The present invention relates to a method for managing an external storage device, and particularly to a method for managing an external storage device that stores a file larger than the working area of a system's built-in memory.

<Prior Art> In a word processor or the like, a created document file is stored in an external storage device such as a floppy disk or a hard disk.

Now, in order to modify a file stored in such an external storage device, the file is read into the internal memory and modified, and then (il correction file is stored after the final file in the external storage device, or (iil Automatically condenses the external storage device and stores it after the final file.

If the file is larger than the working area of the internal memory, the file is divided into subfiles, each subfile is modified, and then (il or (ii)
1 is executed and stored in the external storage device.

<Problem that the invention is trying to solve> However, the above (
Method i) has the problem that the external storage device cannot be used effectively, and method (11) always requires condensation processing, which takes time for storage processing, and also causes negative effects on the processor. There is an audience power of 5. Furthermore, if the file is larger than the capacity of the internal memory, it is necessary to newly generate a subfile, which causes a problem of troublesome correction processing.

In view of the above, an object of the present invention is to provide a method for managing an external storage device that can effectively utilize the storage area of the external storage device, reduce the number of condensation processes (and also eliminate the need to divide files into subfiles). It is to be.

<Means for Solving the Problems> FIG. 1 is a schematic explanatory diagram of a method for managing an external storage device according to the present invention.

11 is an external storage device, lla is a data storage area before modification,
12 is an internal memory, 12a is a work area, 12b is a page management table, and 12c is a free space management table. Note that in the external storage device 11, the shaded area is a data storage area that constitutes a file, and the white area is a free area.

Function> The storage position of each page in the document file stored in the external storage device 11 is managed by the page management table 12b, and the free space in the external storage device 11 is managed by the free space management table 12c. In this state, at least one page of data read from the data storage area 11m of the external storage device 11 is corrected.

If the corrected data fits in the original storage location 11a, the corrected data should be stored in that location (see al), and if it does not fit in the original storage location 11a, it should be stored in another free area 11b (see FIG. 1b). )), if there is no free space in which to store the modified data, the storage state of the external storage device 11 is condensed, and the resulting free space is stored in the free space 11b (see FIG. 1(c)).

<Embodiment> FIG. 2 is a block diagram of a system (for example, a word processor) that implements the present invention, in which 1 is a processor, 2 is a ROM that stores a loading program, 3 is an internal memory (RAM), 4 is a keyboard, 5 is a display device, 6 is a disk controller, 7a to 7C are floppy disks (hereinafter simply referred to as floppy disks), and 8 is a printer. Note that 7a is a system floppy that stores the system program, 7b is a floppy that stores original document files, and 7c is a floppy that stores a work file.The floppy 7c that stores this work file will be used as an external storage device from now on. becomes.

The internal memory RAM 3 includes a system program storage area 3a, a storage area 3b for a page management table that manages the storage location of each page that makes up a document file, and a storage area for a free management table that manages free space in the external storage device 11. 3c, a work area 3d, etc. are provided.

The page management table is stored in a memory for each page (internal memory 3,) and 4P 7b.

7c), the number of bytes of the page, a memory address (pointer) for storing the page, a modification flag indicating whether modification has been made, etc.

FIG. 3 is a flowchart of the process of the present invention. The present invention will be explained below with reference to FIGS. 1 to 3.

It is assumed that the system program has been transferred from the system floppy disk 7a to the storage area 3a of the RAM 3, and that an original document file consisting of multiple pages has been copied as a work file from the floppy disk 7b to the floppy disk 7C. It is assumed that a page management table and a free space management table are generated in areas 3b and 3c, respectively.

Furthermore, the size of the work file is assumed to be larger than the capacity of the work area 3d of the internal memory 3.

Now, due to a request to modify the work file, processor 1
The page management table stored in the storage area 3b of the internal memory 3 is saved in a save area (not shown) under the control of the system program.

(step 100).

Next, the work file data of the specified page is read from the floppy disk 7C and stored in the work area 3d (
(see step 102).

Thereafter, the load status flag and pointer in the page management table of the page read into the work area 3d are updated. The load status flag is expressed, for example, in 2 bits, with "00" indicating the floppy 7a, "01" indicating the floppy 7c, and "10" indicating the internal memory. Further, the pointer indicates the start address of the page in the memory where the page is stored (step 104).

After the above processing, the operator performs predetermined processing such as correction. Note that the modification flag in the page management table of the modified page becomes "1" (step 106).

After the process in step 106, when an operation is performed to write the data in the work area to the floppy disk 7c, the processor 1 determines whether or not corrections such as deletion, addition, change, etc. have been made in the process in step 106 by referring to the correction flag. Step 108), if equivalent correction processing has not been performed, save the page management table in the save area and restore it (Step 110), and then wait for instructions from the law and perform the processing from Step 100 onwards.

On the other hand, if the correction process is performed in step 106, rYEsJ is obtained in step 108. As a result, the processor 1 regards the storage location of the floppy 7c where the page read out in step 102 was stored as a free area, and updates the free space management table (step 11).
2).

Next, the processor determines whether the modified data can be stored in the original storage location, and if so, stores it in the area (see FIG. 1 (al)).

However, if it cannot be stored, it is determined whether it can be stored in another free area, and if there is a free space that can be stored, it is stored in the free area (see FIG. 1 (bl)...step 114. 116 Next, update the free space management table and page management table, and wait for the next instruction (steps 118 and 120).

On the other hand, if there is no free space capable of storing the modified data in step 114, the processor 1
Check whether the floppy disk 7c has been condensed (step 122), and if not, condense the floppy disk 7c (step 124), then proceed to step 112 and subsequent steps.

Incidentally, if the data has already been condensed in step 122, a message indicating that there is no storage location for the corrected data is displayed on the display screen.

Although the floppy disk 7c has been described above as an external storage device, the present invention is not limited to such a case;
Other storage media may also be used.

<Effects of the Invention> According to the present invention, if the corrected data fits in the original storage location, the corrected data is stored at that location, and if it does not fit, the corrected data is stored in another free area and the data is corrected. If there is no free space to store the data, the storage state of the external storage device is condensed and then stored in the free space. This improves the usage efficiency of the external storage device. Since this is only done when there is no available free space, the number of times of condensation can be reduced and the correction process can be shortened. Furthermore, since files are managed in page units, there is no need to divide the file into subfiles even if the file size becomes larger than the capacity of the work area.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of an external storage device management method according to the present invention, FIG. 2 is a block diagram of a system implementing the present invention, and FIG. 3 is a flowchart of the processing of the present invention. 11...External storage device, 11a...Data storage area before correction, 12...Internal memory, 12a...Work area, 12b...Page management table, 12c...Free space management table Patent applicant Alps Electric Co., Ltd. Figure 3 (a)

Claims (1)

[Claims] The file is divided into pages, the storage location of each page is managed by a page management table, free space in an external storage device is managed by a free management table, and the file is read from the external storage device. When at least one page worth of data is modified, it is determined whether the modified data can be stored in the original storage location, and if it is, the modified data is stored in that location, and if it is not, the modified data is stored in that location. A method for managing an external storage device, characterized in that the data is stored in another free space that can store the modified data, and if there is no free space that can store the modified data, the storage state of the external storage device is condensed and then stored in the free space. .