JPS6345636A - Program loading system - Google Patents

Abstract

PURPOSE:To easily correct a program without exchanging the ROM by loading the program stored in a ROM to a main memory and then rewriting the program based on the correction information read out of an external memory medium. CONSTITUTION:A ROM storage program 6 stored in a ROM 1 is loaded to a main memory 5. In this case, the contents of an N address of the program 6 stored in the memory 5 are equal to the contents XN of the program 6. Then the correction information 8 is read out of a floppy disk by a floppy disk device 3. Furthermore the contents of the program 6 in the memory 5 are corrected and written by a floppy disk loader 4 based on the information 8. Thus it is possible to store a corrected program 7 to which the corrected contents are reflected into the memory 5 just with a small quantity of information 8 without exchanging the ROM 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a program loading method, and particularly to a ROM (read only memory; hereinafter the same) and a program loading method.

The present invention relates to a computer program loading method for loading a program into main memory from a removable external storage medium such as a disc.

[Conventional technology]

Conventionally, in this type of program loading method, when the program to be loaded needs to be modified, the ROM is replaced when modifying the program stored in the ROM, and the program stored in the external storage medium is replaced. When making corrections, the stored contents of the external storage medium are rewritten and the program is loaded from a new ROM or the external storage medium with the rewritten stored contents.

[Problem that the invention seeks to solve]

In the conventional program loading method described above, when modifying the program stored in the ROM to be loaded, it is necessary to replace the ROM, so the programs stored in the ROM are limited to basic programs such as loaders. Most of the programs to be loaded are often stored in external storage media.

In such cases, the capacity of the program to be loaded becomes large (the capacity of one program becomes large and the programs loaded simultaneously, such as during initial loading (loading of multiple programs when starting up a computer system)) (including an increase in the number of external storage media) and programs that cannot be stored on one external storage medium (for example, one floppy disk), so programs must be loaded while replacing multiple external storage media ( It has the disadvantage of poor operability.

Also, if you try to reduce the number of programs stored on the external storage medium to improve the ease of loading, the RO
RO is the reason why the number of programs stored in M increases and the program needs to be modified due to program bugs, etc.
This has the disadvantage that the ROM may need to be replaced more often because the possibilities of the program stored in M to be loaded become larger.

SUMMARY OF THE INVENTION In view of the above-mentioned points, an object of the present invention is to update the RO
Modifications can be easily made based on the information stored on the external storage medium without replacing M, and the amount of information stored on the external storage medium is small, so there is no need to worry about replacing the external storage medium, and when the program is loaded. An object of the present invention is to provide a program loading method that can improve operability.

[Means for solving problems]

The program loading method of the present invention includes a ROM for storing a program to be loaded into a main memory, a program loading means for reading the program from the ROM and loading it into the main memory, and a method for modifying the program stored in the ROM. modification information reading means for reading modification information from an external storage medium storing modification information including modification addresses and modification contents; and loading into the main memory based on the modification information read by the modification information reading means. and a program rewriting means for rewriting a part of the program.

[Effect]

In the program loading method of the present invention, a ROM stores a program to be loaded into the main memory, a program loading means reads the program from the ROM and loads it into the main memory,
The modification information reading means reads the modification information for modifying the program stored in the ROM from the external storage medium, and the program rewriting means rewrites the program loaded into the main memory based on the modification information. Rewrite the section.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the program loading method of the present invention. In the program loading method of this embodiment, a ROMI storing a ROM storage program 6 (see FIG. 2) to be loaded into the main memory 5 and a ROM
R to read the stored program 6 and load it into the main memory 5
An OM loader 2, a floppy disk device 3 that reads correction information 8 from a floppy disk in which a correction information 8 (see FIG. 2) is written for correcting the ROM stored program 6, and a floppy disk device 3. main memory 5 based on the correction information 8 read by
A modified program 7 is composed of a floppy disk loader 4 that rewrites the contents of the ROM stored program 6 loaded into the ROM storage program 6, and a RAM (random access memory), and the ROM stored program 6 is modified based on modification information 8 (FIG. 2). (see) and a main memory 5 in which are stored.

Next, the operation of the program loading method of this embodiment configured as described above will be explained. Here, as shown in FIG. 2, the ROM storage program 6 stored in the ROMI (the contents of address A+1 are XA, the contents of address A+1 are Xa*++, the contents of address N are XN, . ... (each address is indicated by the address on the main memory 5 when loaded into the main memory 5)) is stored in the floppy disk (ROM storage program 6).
Contents that address N (1m correct address) is Y (correction content)
An example will be described in which a modified program 7 is stored in the main memory 5 based on the modified program 7 (including information instructing modification to be performed).

When it becomes necessary to modify the contents of the ROM storage program 6 to be loaded into the main memory 5, the modification address, which is the address to be modified, and the modification contents, which are the contents after the contents of that address are modified, are made to correspond. The modification information 8 shown is written to the floppy disk.

When the ROM storage program 6 and the modification information 8 are prepared as described above, the ROM storage program 6 stored in the ROMI is first loaded into the main memory 5.

In the example shown in FIG. 2, the content at address N of the program loaded onto the main memory 5 at this time is XH, which is the same as the content of the ROM stored program 6.

Next, the correction information 8 written on the floppy disk is read by the floppy disk device 3.

Based on this modification information 8, the contents of the program loaded into the main memory 5 by the floppy disk loader 4 are modified and written.

In the example shown in FIG. 2, Yo is written to the contents of address N whose contents are XN (correction contents are also written to the contents of other addresses that require correction based on correction information 8).
.

In this way, the modified program 7 that reflects the modified content is stored in the main memory 5 using only a small amount of modification information 8 without the need to replace the ROMI.

In this embodiment, a case has been described in which a floppy disk is used as a removable external storage medium, but it is also possible to use other external storage media such as a cassette magnetic tape.

Furthermore, in this embodiment, a case has been described in which the correction address in the correction information 8 indicates the absolute address on the main memory 5 when the ROM storage program 6 is loaded, but the starting address of the ROM storage program 6 is assumed to be the O address. It may also be indicated by a relative address.

〔Effect of the invention〕

As explained above, the present invention loads the program stored in the ROM into the main memory and rewrites the program based on the modification information G read from the external storage medium. This has the advantage that when a need for correction arises, it can be easily corrected based on the correction information stored in the external storage medium without replacing the ROM.

Additionally, in this case, the amount of information stored in the external storage medium can be reduced to just the correction information, which has the effect of improving operability when loading programs without the hassle of replacing the external storage medium. be.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention.
FIG. 7 is a diagram illustrating an example of an operation when loading a stored program into main memory and modifying it based on modification information. In the figure, ■...ROM. 2... ROM loader, 3... Floppy disk device, 4... Floppy disk loader, 5... Main memory, 6... ROM storage program, 7... Modified program, 8... This is correction information.

Claims (1)

[Scope of Claims] A ROM that stores a program to be loaded into a main memory, a program loading means that reads the program from the ROM and loads it into the main memory, and a modification for modifying the program stored in the ROM. modification information reading means for reading modification information including an address and modification information from an external storage medium in which the modification information is stored; A program loading method comprising: program rewriting means for rewriting part of the program.