Bottom Text.exe

#include <stdio.h>
#include <stdlib.h>
#define MaxProgSize  100
#define MaxMemSize  50

struct Instruction {int OpCode, Address;
};


	struct Instruction IM[MaxProgSize];
	struct Instruction MDR1;
	struct Instruction IR;
	int DM[MaxMemSize];
	int PC = 0, MAR, MDR2, A;
	int j = 0;

	struct Instruction fetchExe();
	int load();
	int add();
	int store();
	int subt();
	int in();
	int out();
	void end();
	int jmp();
	int skipz();

int main(int argc, char *argv[]){
	 int c;
	 int i;
    //Pointing towards the input file Final.txt
    FILE *Final;

//Instead of using Final = fopen(argv[1], "r"); ,
//I used this because the command line in DevC++ does not read my file "Final.txt" if it sets on argv[1]
    Final = fopen("Final.txt", "r");
//    if the file does not exist,
	if (Final == NULL)
	printf("Cannot open file!");
//	if it exists and does work.
    else {
        printf("Assembling Program...\n");
        int i = 0;
        while ((c = getc(Final)) != EOF){
            c-='0';
            if(c<0||c>9){
                continue;
            }
            if(i%2==0){
                IM[PC+i/2].OpCode=c;
            }else{
                IM[PC+i/2].Address=c;
            }
            i++;
        }
        printf("Program assembled\n Run.\n");

			printf("PC = %d \t A = %d \t MEM = [",PC,A);
    		for(j=0;j<MaxMemSize-1;j++){
        		printf("%d, ",DM[j]);
    		}
    		printf("%d]\n",DM[j]);



	while(MaxProgSize > A ){
		switch(IR.OpCode){
			case 0: fetchExe();
				break;
			case 1: load();{
			printf("PC = %d \t A = %d \t MEM = [",PC,A);
    		for(j=0;j<MaxMemSize-1;j++){
        		printf("%d, ",DM[j]);
    		}
    		printf("%d]\n",DM[j]);
    		}
			break;
			case 2: add();{
			printf("PC = %d \t A = %d \t MEM = [",PC,A);
    		for(j=0;j<MaxMemSize-1;j++){
        		printf("%d, ",DM[j]);
    		}
    		printf("%d]\n",DM[j]);
    		}
			break;
			case 3: store();{
			printf("PC = %d \t A = %d \t MEM = [",PC,A);
    		for(j=0;j<MaxMemSize-1;j++){
        		printf("%d, ",DM[j]);
    		}
    		printf("%d]\n",DM[j]);
    		}
			break;
			case 4: subt();{
			printf("PC = %d \t A = %d \t MEM = [",PC,A);
    		for(j=0;j<MaxMemSize-1;j++){
        		printf("%d, ",DM[j]);
    		}
    		printf("%d]\n",DM[j]);
    		}
			break;
			case 5: in();{
			printf("PC = %d \t A = %d \t MEM = [",PC,A);
    		for(j=0;j<MaxMemSize-1;j++){
        		printf("%d, ",DM[j]);
    		}
    		printf("%d]\n",DM[j]);
    		}
			break;
			case 6: out();
			break;
			case 7: end();
			break;
			case 8: jmp();{
			printf("PC = %d \t A = %d \t MEM = [",PC,A);
    		for(j=0;j<MaxMemSize-1;j++){
        		printf("%d, ",DM[j]);
    		}
    		printf("%d]\n",DM[j]);
    		}
			break;
			case 9: skipz();{
			printf("PC = %d \t A = %d \t MEM = [",PC,A);
    		for(j=0;j<MaxMemSize-1;j++){
        		printf("%d, ",DM[j]);
    		}
    		printf("%d]\n",DM[j]);
    		}
			break;
		}
	}
        printf("Program Complete\n");
        fclose(Final);
    }
    system("PAUSE");
    return 0;
}
//Fetching instructions and address to perform operations
struct Instruction fetchExe(){
	MAR = PC;
	PC = PC +1;
	MDR1 = IM[MAR];
	IR = MDR1;
	return IR;
}

//loading the value from Accumulator from DM
int load(){
	printf("/*Loading Accumulator to DM %d */ \n", IR.Address);
	MAR = IR.Address;
	MDR2 = DM[MAR];
	A = MDR2;
	IR.OpCode = 0;
	return IR.OpCode;
}


//Adding the value of the loaded address to the target address
int add(){
	MAR = IR.Address;
	MDR2 = DM[MAR];
	printf("/*Adding %d and %d */ \n", A, MDR2);
	A = A + MDR2;
	IR.OpCode = 0;
	return IR.OpCode;
}

//Storing the value to the target address
int store(){
	printf("/* Storing Accumulator to memory %d */ \n", IR.Address);
	MAR = IR.Address;
	MDR2 = A;
	DM[MAR] = MDR2;
	IR.OpCode = 0;
	return IR.OpCode;
}

//Subtracting the value of the loaded address to the target address
int subt(){
	MAR  = IR.Address;
	MDR2 = DM[MAR];
	printf("/*Subtracting %d and %d */ \n", A, MDR2);
	A = A - MDR2;
	IR.OpCode = 0;
	return IR.OpCode;
}

//Inputting value
int in(){
	printf("/* Input value */ \n");
    printf("Enter a number: ");
    scanf("%d",&A);
	IR.OpCode = 0;
	return IR.OpCode;
}

//showing the value by printing it
int out(){
	printf("/* Outputting accumulator to screen */ \n");
		printf("PC = %d \t A = %d \t MEM = [",PC,A);
    for(j=0;j<MaxMemSize-1;j++){
        printf("%d, ",DM[j]);
    }
    printf("%d]\n",DM[j]);
	IR.OpCode = 0;
	return IR.OpCode;
}


void end(){
	printf("/*Program terminated.*/ \n");
	exit(1);
}

int jmp(){
	int i;
	PC = IR.Address;
	printf("/*Jumping to %d */ \n", PC);
	IR.OpCode = 0;
	return IR.OpCode;
}

int skipz(){
	int i;
	if(A == 0){
	PC = PC +1;
	IR.OpCode = 0;
	return IR.OpCode;
	}
}