Now execute circles not get passed to execute variable - it can check now if there is EOF

src/6502/main.c

@@ -4,7 +4,6 @@
 
 struct CPU cpu;
 struct MEMORY mem;
-byte cycles;
 
 void memory_init () {
 	for (int i = 0; i < MAX_MEMORY; i++){
@@ -32,7 +31,6 @@ void dump_cpu(struct CPU cpu) {
 byte fetch_byte() {
 	byte data = mem.memory[cpu.PC];
 	cpu.PC++;
-	cycles--;
 	return data;
 }
 
@@ -42,14 +40,12 @@ word fetch_word() {
 
 	data |= (mem.memory[cpu.PC] << 8);
 	cpu.PC++;
-	cycles -= 2;
 
 	return data;
 }
 
 byte read_byte(word addr) {
 	byte data = mem.memory[addr];
-	cycles--;
 	cpu.PC++;
 	return data;
 }
@@ -59,28 +55,20 @@ word read_word(word addr) {
 	data |= (mem.memory[addr+1] << 8);
 	cpu.PC++;
 	cpu.PC++;
-	cycles -= 2;
 	return data;
 }
 
 void write_byte(byte addr, byte value) {
 	mem.memory[addr] 	= value;
-	cycles--;
 }
 
 void write_word(byte addr, word value) {
 	mem.memory[addr] 	= value & 0xFF;
 	mem.memory[addr+1] 	= (value >> 8);
-	cycles -= 2;
 }
 
-void execute(byte exec_cycles) {
-	cycles = exec_cycles;
-	if (cycles <= 0) {
-		printf("ERROR\n");
-		exit(1);
-	}
-	while (cycles > 0) {
+void execute() {
+	while (1) {
 		byte instruction = fetch_byte();
 		switch(instruction) {
 			case INS_LDA_IM: 
@@ -97,7 +85,6 @@ void execute(byte exec_cycles) {
 				break;
 			case INS_LDA_ZPX: 
 				byte zero_page_x_addr = cpu.X + fetch_byte();
-				cycles--;
 				cpu.A = read_byte(zero_page_x_addr);	
 				cpu.Z = (cpu.A == 0);
 				cpu.N = (cpu.A & 0b1000000) > 0;
@@ -117,7 +104,6 @@ void execute(byte exec_cycles) {
 				break;
 			case INS_LDX_ZPY:
 				byte zero_page_y_addr = cpu.Y + fetch_byte();
-				cycles--;
 				cpu.X = read_byte(zero_page_y_addr);	
 				cpu.Z = (cpu.X == 0);
 				cpu.N = (cpu.X & 0b1000000) > 0;
@@ -137,7 +123,6 @@ void execute(byte exec_cycles) {
 				break;
 			case INS_LDY_ZPX:
 				zero_page_x_addr = cpu.Y + fetch_byte();
-				cycles--;
 				cpu.Y = read_byte(zero_page_x_addr);	
 				cpu.Z = (cpu.Y == 0);
 				cpu.N = (cpu.Y & 0b1000000) > 0;
@@ -148,14 +133,15 @@ void execute(byte exec_cycles) {
 				write_word(cpu.PC - 1, cpu.SP);
 				cpu.SP++;
 				cpu.PC = jsr_addr;
-				cycles--;
 				break;
 			case INS_RTS:
 				// TODO
 				break;
+		        case 0xFF: // EOF
+			        return;
 			default: 
 				printf("%04X: Unhandled instruction: %04X\n", cpu.PC, instruction);
-				cycles = 0;
+				return;
 		}
 	}
 }
@@ -172,8 +158,9 @@ int main(int argc, char *argv[]) {
 	  mem.memory[pos] = ch;
 	  pos++;
 	}
+	mem.memory[pos] = EOF;
         
-	execute(5); // FIXME: count how many circles is needed based on instructions
+	execute();
 	dump_cpu(cpu);
 	return 0;
 }

src/6502/test.bin

@@ -1 +1 @@
-ｩVV
+ｩVｩdｩB