JPH03211638A - Compression system for program backup file - Google Patents

Abstract

PURPOSE:To reduce the capacity of an external storage device by providing the correspondence allocation table of a program area and compressing the backup file of a program on a main storage device so as to provided it on the external storage device. CONSTITUTION:The main storage device 1 is provided with the correspondence allocation table (TBL) 11 of the program area 12 and the program area on the backup file 21 in a hard disk 2. The leading address and the tailing address of the areas in using programs A and B in the program area 12, and the leading addresses of program areas A' and B' in the backup file 21 are correspondingly allocated to TBL 11 and are controlled. When the tailing address of the area of the using program A and the leading address of the area in the using program B are allowed to correspond to the leading address of the program area B' in the backup file 21, the area of an unused program (a) is not allocated to the backup file 21. Thus, the capacity of the hard disk can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a compression method for program backup files in an electronic exchange system.

[Conventional technology]

In conventional electronic exchange systems, the hard disk has a backup file that corresponds one-to-one with the program on the main storage device.

[Problem to be solved by the invention]

Generally, an unused area is reserved in the main memory where processing does not run in consideration of system expandability, but in the conventional electronic switching system described above, the main memory is Since there is a one-to-one correspondence between the program on the storage device 4 and the backup file on the hard disk 5, there is also an area on the hard disk 5 for this unused program a, which has the disadvantage that the backup file becomes large. Furthermore, since multiple backup files are usually required, there is a drawback that a relatively large capacity hard disk is required.

[Means to solve the problem]

The program backup file compression method of the present invention provides an electronic exchange system including a main storage device, an external storage device, and a central processing unit, in which the main storage device has a program area and a program area on the external storage device. The central processing unit includes a correspondence allocation table, and the central processing unit includes compression control means for compressing a backup file of the program on the main storage device and storing it in the external storage device.

〔Example〕

Next, the present invention will be explained with reference to FIGS. 1 to 4.

Fig. 1 is a block diagram of an electronic exchange system showing an embodiment of the present invention, Fig. 2 is a diagram showing an example of the correspondence allocation table in Fig. 1, and Figs. 3 and 4 are central processing in Fig. 1. It is a figure which shows the program read-out procedure of a device, and a program write-in procedure.

As shown in FIG. 1, the electronic exchange system of this embodiment has a main memory device (hereinafter referred to as MM
) 2 and a central processing unit (hereinafter referred to as CPLl) 3, the MMI includes a program area 12 and a correspondence layout table (hereinafter referred to as TBL) 11 between the program area 12 and the program areas on the backup file 21 of the DK2. We are prepared. Note that the program area 12 has programs A and B in use and an unused program a, and the backup file 21 has only a program area A'B'.

As shown in Figure 2, TBLII contains the start address and end address (both absolute addresses) of the area of the program A in use in the program area 12, and the start address (physical address) of the program area A' of the backup file 21. , and the start address and end address of the area of the program B in use in the program area 12 and the start address of the program area B' of the backup file 21 are allocated and managed in a corresponding manner. If the last address of the area of the program A in use and the start address of the area of the program B in use are both made to correspond to the start address of the program area B' of the backup file 21,
The area of unused program a is not allocated to the backup file 21.

Next, program reading and program writing operations by the CPU 3 in this embodiment will be explained.

First, when reading a program from DK2 to MMI, as shown in Figure 3, CPU3 creates TBLI 1 at the initial setting of MMl, and thereafter uses TBLll when reading a program to MM1 since there is no change in TBL. The programs on program areas A' and B' of the backup file 21 of the DK2 are read out.

Next, when writing a program from the MMI to the DK2, as shown in FIG.
Write to the program areas A' and B' of the backup file 21 of the DK2 according to the correspondence of I. Also, since the unused program a in the program area 12 has no corresponding area on the backup file 21, TBLl
After updating l and securing a corresponding area (not shown) on the DK2, the data is written there.

〔Effect of the invention〕

As explained above, the present invention has a correspondence allocation table between the program area on the main storage device and the program area on the external storage device, compresses the backup file of the program on the main storage device, and stores it on the external storage device. This has the effect of reducing the capacity of the external storage device.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an electronic exchange system showing an embodiment of the present invention, Fig. 2 is a diagram showing an example of the correspondence allocation table in Fig. 1, and Figs. 3 and 4 are central processing in Fig. 1. Device program reading procedure. FIG. 5, which is a diagram showing a program writing procedure, is a diagram showing an example of a conventional program allocation image between a main storage device and a hard disk. 1.4... Main memory (MM), 2.5... Hard disk (DK), 3... Central processing unit (CPU),
11... Layout correspondence table (TBL), 12... Program area, 2 1... Backup file.

Claims (1)

[Claims] In an electronic switching system including a main storage device, an external storage device, and a central processing unit, the main storage device is provided with a correspondence layout table between its program area and the program area on the external storage device, and the central processing unit A compression method for a program backup file, comprising compression control means for compressing a program backup file on the main storage device and storing the compressed program backup file in the external storage device.