Computer system

• US 5,220,667 A
• Filed: 09/19/1990
• Issued: 06/15/1993
• Est. Priority Date: 09/25/1989
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Ichieda, Keisuke
• Primary Examiner(s): Bowler, Alyssa H.
• Application Number:
  US07/584,606
• Time in Patent Office: 1,000 Days
• Field of Search: 395/600, 395/425, 395/400, 395/700, 364/DIG. 1, 364/222.81, 364/280.2, 364/946.9, 364/957.1, 364/975.2
• US Class Current: 713/1
• CPC Class Codes: G06F 9/4406 Loading of operating system

Abstract

A computer system according to this invention makes it possible to perform initial loading of files directly from an auxiliary memory according to a check code in a management table in a battery-backed-up memory. In direct file loading, the auxiliary memory is accessed as per physical addresses and sizes of each of the blocks constituting each file to be loaded. This direct reading of necessary files enables to reduce significantly the number of times the auxiliary memory is accessed for the purpose, thereby shortening the time required for initial loading of the files.

Claims

1. A computer system comprising:

a main memory means to which a file is loaded when said system is powered on or reset;

an auxiliary memory means for storing said file in units of blocks;

a memory means, backed up by a battery, for storing a management table which contains physical addresses and sizes of each of said blocks of said file on said auxiliary memory means, and a check code for checking to see if the contents of said file'"'"'s information are properly retained; and

a judging means, based on said check code in said management table, for deciding whether said file is to be loaded from said auxiliary memory means to said main memory means in accordance with a conventional file selection method or in a direct manner as per said physical addresses and sizes found in said management table.

2. An apparatus as claimed in claim 1 wherein the main memory means comprises a random access memory.

3. An apparatus as claimed in claim 1 wherein the auxiliary memory means is selected for the group consisting of a magnetic disk device, an optical read/write device, and a magnetic tape device.

4. An apparatus as claimed in claim 1 wherein the memory means comprises a random access memory.

5. A method for initial loading of computer program files into a computer main memory which comprises the steps of:

providing a computer system with at least a main memory, an auxiliary memory, a memory backed-up by battery power, and a judging means for comparing a check code with auxiliary memory contents;

providing said auxiliary memory with said program files;

creating a management table containing file location and file size data of all said files on said auxiliary memory, the size of said management table, and a check code;

storing said management table in said memory backed-up by battery power;

comparing said check code with auxiliary memory contents for establishing the accuracy of said management table;

loading said program files either in accordance with conventional file selection method or in a direct manner as per said file location and said file size data found in said management table based on said comparison of said check code with said auxiliary memory contents.

6. A method as claimed in claim 5 wherein the steps of comparing said check code further comprises:

initializing said computer system;

computing file data of said auxiliary memory;

reading said check code from said management table; and

comparing said check code with said file data of said auxiliary memory for equivalency.

7. A method as claimed in claim 6 wherein the step of loading said program files further comprises:

loading said program files from said file location and said file size data stored in said management table when said check code is equivalent to said file data;

loading said program file in accordance with said conventional file selection method when said check code is not equivalent to said file data; and

rewriting said management table when said check code is not equivalent to said file data.