simpletron_v2.c

#include<stdio.h>
#include<stdlib.h>
#define READ    10
#define WRITE   11
#define LOAD    20
#define STORE   21
#define ADD     30
#define SUBTRACT 31
#define DIVIDE  32
#define MULTIPLY 33
#define BRANCH 40
#define BRANCHNEG 41
#define BRANCHZERO 42
#define HALT 43



int main()
{
    int memory[100] = { 0 };
    int accumulator = 0;
    int instruction_counter = 0; //boot address - 0000
    int instruction_register = 0;
    int operation_code = 0;
    int operand = 0;
    /*
    FILE* fp;
    fopen_s(&fp,"d:\\test.txt", "w");
    if (fp != NULL)
    {
        fprintf_s(fp, "%d\n", 1050);
        fprintf_s(fp, "%d\n", 2050);
        fprintf_s(fp, "%d\n", 1051);
        fprintf_s(fp, "%d\n", 3051);
        fprintf_s(fp, "%d\n", 2152);
        fprintf_s(fp, "%d\n", 1152);
        fprintf_s(fp, "%d\n", 4300);
        fclose(fp);
    }
    */
    int index = 0;
    FILE* fin;
    fopen_s(&fin, "D:\\test.txt", "r");
    printf("EOF = %d\n\n", EOF);
    if (fin != NULL)
    {
        while (fscanf_s(fin, "%d", &memory[index++]) > 0)
        {

        }


        fclose(fin);
    }



    //LOAD PROGRAM INTO MEMORY
    //memory[0] = 1050;
    //memory[1] = 2050;
    //memory[2] = 1051;
    //memory[3] = 3051;
    //memory[4] = 2152;
    //memory[5] = 1152;
    //memory[6] = 4300;

    while (1)
    {
        instruction_register = memory[instruction_counter++];
        operation_code = instruction_register / 100;
        operand = instruction_register % 100;
        switch (operation_code)
        {
        case 10:
            scanf_s("%d", &memory[operand]);
            break;
        case 11:
            printf("%d", memory[operand]);
            break;
        case 20:
            accumulator = memory[operand];
            break;
        case 21:
            memory[operand] = accumulator;
            break;
        case 30:
            accumulator += memory[operand];
            break;
        case 31:
            accumulator -= memory[operand];
            break;
        case 32:
            accumulator /= memory[operand];
            break;
        case 33:
            accumulator *= memory[operand];
            break;
        case 40:
            instruction_counter = operand;
            break;
        case 41:
            if (accumulator < 0)
            {
                instruction_counter = operand;
            }
            break;
        case 42:
            if (accumulator == 0)
            {
                instruction_counter = operand;
            }
            break;
        case 43:
            printf("Program is terminated!");
            exit(0);
            break;
        default:
            printf("Err! No such instruction!!!! . Program is terminated!");
            exit(0);
            break;
        }

    }


    return 0;
}