add LD_(BC)_A() opcode

src/cpu.cpp

@@ -27,7 +27,7 @@ CPU::CPU()
 int CPU::NOP()
 {
 	reg_PC.dat += 1;
-	printf("NOP");
+	printf("NOP\n");
 	return 4;
 }
 
@@ -40,10 +40,24 @@ int CPU::LD_BC_u16()
 	// OR the second byte
 	reg_BC.dat = ((*mMap)[reg_PC.dat + 1] << 8) | (*mMap)[reg_PC.dat + 2];
 	reg_PC.dat += 3;
-	printf("LD BC, u16");
+	printf("LD BC, u16\n");
 	return 12;
 }
 
+// LD (BC), A
+// Loads the contents of A into the memory address pointed to by BC
+int CPU::LD_BC_A()
+{
+	// Write the contents of A into the memory address pointed to by BC
+	mMap->writeMemory(reg_BC.dat, reg_AF.lo);
+
+	// Increment the program counter
+	reg_PC.dat += 1;
+
+	printf("LD (BC), A\n");
+	return 8;
+}
+
 int CPU::executeNextInstruction()
 {
 	// Get the opcode

src/cpu.h

@@ -56,10 +56,10 @@ class CPU
 	// ISA
 	// Pulled from https://izik1.github.io/gbops/index.html
 	typedef int (CPU::*method_function)();
-	method_function method_pointer[0x02] = {
+	method_function method_pointer[0x03] = {
 		&CPU::NOP,
-		&CPU::LD_BC_u16
-		// &CPU::LD_BC_A,
+		&CPU::LD_BC_u16,
+		&CPU::LD_BC_A
 		// &CPU::INC_BC,
 		// &CPU::INC_B,
 		// &CPU::DEC_B,
@@ -321,6 +321,9 @@ class CPU
 	// LD nn, nn
 	int LD_BC_u16();
 
+	// LD (BC), A
+	int LD_BC_A();
+
 public:
 	const int clockSpeed = 4194304; // 4.194304 MHz CPU
 	const int clockSpeedPerFrame = 70224; // 4194304 / 59.73fps
@@ -330,5 +333,7 @@ class CPU
 	// set the memory map
 	void setMemory(MemoryMap* memory) { mMap = memory; }
 
+	void set_reg_BC(Word value) { reg_BC.dat = value; }
+
 	int executeNextInstruction();
 };

src/gameBoy.cpp

@@ -17,6 +17,9 @@ GBE::GBE()
 	gbe_mMap->debugWriteMemory(0x0101, 0x01);
 	gbe_mMap->debugWriteMemory(0x0102, 0x02);
 	gbe_mMap->debugWriteMemory(0x0103, 0x03);
+	gbe_cpu->set_reg_BC(0x8001); 
+	gbe_mMap->debugWriteMemory(0x0104, 0x02);
+	gbe_mMap->debugWriteMemory(0x0105, 0x04);
 
 	update();
 }