diff --git a/Ricoh2A03/inc/Ricoh2A03.h b/Ricoh2A03/inc/Ricoh2A03.h
index 1264900..d32ee6d 100644
--- a/Ricoh2A03/inc/Ricoh2A03.h
+++ b/Ricoh2A03/inc/Ricoh2A03.h
@@ -11,7 +11,7 @@ namespace EightBit {
 		virtual ~Ricoh2A03() = default;
 
 	protected:
-		virtual uint8_t sub(uint8_t operand, int borrow) noexcept final;
-		virtual uint8_t add(uint8_t operand, int carry) noexcept final;
+		uint8_t sub(uint8_t operand, int borrow) noexcept final;
+		void adc() noexcept final;
 	};
 }
\ No newline at end of file
diff --git a/Ricoh2A03/src/Ricoh2A03.cpp b/Ricoh2A03/src/Ricoh2A03.cpp
index b63690c..f99fa76 100644
--- a/Ricoh2A03/src/Ricoh2A03.cpp
+++ b/Ricoh2A03/src/Ricoh2A03.cpp
@@ -6,11 +6,9 @@ EightBit::Ricoh2A03::Ricoh2A03(Bus& bus)
 }
 
 uint8_t EightBit::Ricoh2A03::sub(uint8_t operand, int borrow) noexcept {
-	const auto data = BUS().DATA();
-	return MOS6502::sub_b(operand ,data, borrow);
+	return MOS6502::sub_b(operand, borrow);
 }
 
-uint8_t EightBit::Ricoh2A03::add(uint8_t operand, int carry) noexcept {
-	const auto data = BUS().DATA();
-	return MOS6502::add_b(operand, data, carry);
+void EightBit::Ricoh2A03::adc() noexcept {
+	MOS6502::adc_b();
 }