diff --git a/Gaming/inc/Game.h b/Gaming/inc/Game.h
index c0d1fec..8cfa49a 100644
--- a/Gaming/inc/Game.h
+++ b/Gaming/inc/Game.h
@@ -23,7 +23,7 @@ namespace Gaming {
 		virtual ~Game();
 
 		virtual void runLoop();
-		void raisePOWER() override;
+		void raisePOWER() noexcept override;
 
 	protected:
 		[[nodiscard]] virtual float fps() const noexcept = 0;
diff --git a/Gaming/src/Game.cpp b/Gaming/src/Game.cpp
index a3a9c4e..a6ee8e5 100644
--- a/Gaming/src/Game.cpp
+++ b/Gaming/src/Game.cpp
@@ -25,7 +25,7 @@ int Game::displayHeight() const noexcept {
 	return rasterHeight();
 }
 
-void Game::raisePOWER() {
+void Game::raisePOWER() noexcept {
 
 	Device::raisePOWER();
 
diff --git a/Intel8080/inc/Intel8080.h b/Intel8080/inc/Intel8080.h
index f2f790a..c66538e 100644
--- a/Intel8080/inc/Intel8080.h
+++ b/Intel8080/inc/Intel8080.h
@@ -32,8 +32,8 @@ namespace EightBit {
 		Signal<Intel8080> ExecutingInstruction;
 		Signal<Intel8080> ExecutedInstruction;
 
-		virtual int execute() final;
-		virtual int step() final;
+		int execute() noexcept final;
+		int step() noexcept final;
 
 		[[nodiscard]] const register16_t& AF() const noexcept final;
 		[[nodiscard]] auto& AF() noexcept { return IntelProcessor::AF(); }
@@ -51,14 +51,14 @@ namespace EightBit {
 		[[nodiscard]] bool requestingWrite() noexcept { return lowered(WR()); }
 
 	protected:
-		void handleRESET() final;
-		void handleINT() final;
+		void handleRESET() noexcept final;
+		void handleINT() noexcept final;
 
-		void memoryWrite() final;
-		uint8_t memoryRead() final;
+		void memoryWrite() noexcept final;
+		uint8_t memoryRead() noexcept final;
 
-		void busWrite() final;
-		uint8_t busRead() final;
+		void busWrite() noexcept final;
+		uint8_t busRead() noexcept final;
 
 	private:
 		bool m_requestIO = false;
diff --git a/Intel8080/src/Intel8080.cpp b/Intel8080/src/Intel8080.cpp
index cbe164f..9fa596e 100644
--- a/Intel8080/src/Intel8080.cpp
+++ b/Intel8080/src/Intel8080.cpp
@@ -37,39 +37,39 @@ const EightBit::register16_t& EightBit::Intel8080::HL() const noexcept {
 	return hl;
 }
 
-void EightBit::Intel8080::memoryWrite() {
+void EightBit::Intel8080::memoryWrite() noexcept {
 	requestMemory();
 	IntelProcessor::memoryWrite();
 	releaseMemory();
 }
 
-uint8_t EightBit::Intel8080::memoryRead() {
+uint8_t EightBit::Intel8080::memoryRead() noexcept {
 	requestMemory();
 	const auto returned = IntelProcessor::memoryRead();
 	releaseMemory();
 	return returned;
 }
 
-void EightBit::Intel8080::busWrite() {
+void EightBit::Intel8080::busWrite() noexcept {
 	requestWrite();
 	IntelProcessor::busWrite();
 	releaseWrite();
 }
 
-uint8_t EightBit::Intel8080::busRead() {
+uint8_t EightBit::Intel8080::busRead() noexcept {
 	requestRead();
 	const auto returned = IntelProcessor::busRead();
 	releaseRead();
 	return returned;
 }
 
-void EightBit::Intel8080::handleRESET() {
+void EightBit::Intel8080::handleRESET() noexcept {
 	IntelProcessor::handleRESET();
 	di();
 	tick(3);
 }
 
-void EightBit::Intel8080::handleINT() {
+void EightBit::Intel8080::handleINT() noexcept {
 	IntelProcessor::handleINT();
 	raiseHALT();
 	if (m_interruptEnable) {
@@ -310,7 +310,7 @@ uint8_t EightBit::Intel8080::portRead() {
 	return returned;
 }
 
-int EightBit::Intel8080::step() {
+int EightBit::Intel8080::step() noexcept {
 	ExecutingInstruction.fire(*this);
 	resetCycles();
 	if (LIKELY(powered())) {
@@ -328,7 +328,7 @@ int EightBit::Intel8080::step() {
 	return cycles();
 }
 
-int EightBit::Intel8080::execute() {
+int EightBit::Intel8080::execute() noexcept {
 
 	const auto& decoded = getDecodedOpcode(opcode());
 
diff --git a/Intel8080/test/Board.cpp b/Intel8080/test/Board.cpp
index e78de3f..2799beb 100644
--- a/Intel8080/test/Board.cpp
+++ b/Intel8080/test/Board.cpp
@@ -10,14 +10,14 @@ Board::Board(const Configuration& configuration)
   m_disassembler(*this) {
 }
 
-void Board::raisePOWER() {
+void Board::raisePOWER() noexcept {
 	EightBit::Bus::raisePOWER();
 	CPU().raisePOWER();
 	CPU().raiseRESET();
 	CPU().raiseINT();
 }
 
-void Board::lowerPOWER() {
+void Board::lowerPOWER() noexcept {
 	CPU().lowerPOWER();
 	EightBit::Bus::lowerPOWER();
 }
diff --git a/Intel8080/test/Board.h b/Intel8080/test/Board.h
index b765e4b..ba86b67 100644
--- a/Intel8080/test/Board.h
+++ b/Intel8080/test/Board.h
@@ -17,8 +17,8 @@ public:
 	EightBit::Intel8080& CPU() { return m_cpu; }
 	const EightBit::Intel8080& CPU() const { return m_cpu; }
 
-	virtual void raisePOWER() final;
-	virtual void lowerPOWER() final;
+	void raisePOWER() noexcept final;
+	void lowerPOWER() noexcept final;
 
 	virtual void initialise() final;
 
diff --git a/LR35902/fusetest_LR35902/FuseTestRunner.cpp b/LR35902/fusetest_LR35902/FuseTestRunner.cpp
index 65ed458..037a69f 100644
--- a/LR35902/fusetest_LR35902/FuseTestRunner.cpp
+++ b/LR35902/fusetest_LR35902/FuseTestRunner.cpp
@@ -9,7 +9,7 @@ Fuse::TestRunner::TestRunner(const Test& test, const ExpectedTestResult& expecte
 
 //
 
-void Fuse::TestRunner::raisePOWER() {
+void Fuse::TestRunner::raisePOWER() noexcept {
 	EightBit::Bus::raisePOWER();
 	CPU().raisePOWER();
 	CPU().raiseRESET();
@@ -18,7 +18,7 @@ void Fuse::TestRunner::raisePOWER() {
 	initialiseMemory();
 }
 
-void Fuse::TestRunner::lowerPOWER() {
+void Fuse::TestRunner::lowerPOWER() noexcept {
 	CPU().lowerPOWER();
 	EightBit::Bus::lowerPOWER();
 }
diff --git a/LR35902/fusetest_LR35902/FuseTestRunner.h b/LR35902/fusetest_LR35902/FuseTestRunner.h
index 8603301..d378639 100644
--- a/LR35902/fusetest_LR35902/FuseTestRunner.h
+++ b/LR35902/fusetest_LR35902/FuseTestRunner.h
@@ -46,8 +46,8 @@ namespace Fuse {
 		bool failed() const { return m_failed; }
 		bool unimplemented() const { return m_unimplemented; }
 
-		virtual void raisePOWER() final;
-		virtual void lowerPOWER() final;
+		void raisePOWER() noexcept final;
+		void lowerPOWER() noexcept final;
 
 		void initialise();
 	};
diff --git a/LR35902/inc/GameBoyBus.h b/LR35902/inc/GameBoyBus.h
index 38b1aca..261d433 100644
--- a/LR35902/inc/GameBoyBus.h
+++ b/LR35902/inc/GameBoyBus.h
@@ -36,8 +36,8 @@ namespace EightBit {
 
 			Bus() noexcept;
 
-			virtual void raisePOWER() override;
-			virtual void lowerPOWER() override;
+			void raisePOWER() noexcept override;
+			void lowerPOWER() noexcept override;
 
 			[[nodiscard]] auto& CPU() noexcept { return m_cpu; }
 			[[nodiscard]] auto& VRAM() noexcept { return m_videoRam; }
diff --git a/LR35902/inc/LR35902.h b/LR35902/inc/LR35902.h
index 4839350..b4b7c0d 100644
--- a/LR35902/inc/LR35902.h
+++ b/LR35902/inc/LR35902.h
@@ -47,22 +47,22 @@ namespace EightBit {
 			void tickMachine() { tick(4); MachineTicked.fire(); }
 
 		protected:
-			int execute() final;
-			int step() final;
+			int execute() noexcept final;
+			int step() noexcept final;
 
-			void handleRESET() final;
-			void handleINT() final;
+			void handleRESET() noexcept final;
+			void handleINT() noexcept final;
 
-			void memoryWrite() final;
-			uint8_t memoryRead() final;
+			void memoryWrite() noexcept final;
+			uint8_t memoryRead() noexcept final;
 
-			void pushWord(register16_t value) final;
+			void pushWord(register16_t value) noexcept final;
 
-			void jr(int8_t offset) final;
-			int jumpConditional(int condition) final;
-			int returnConditional(int condition) final;
-			int jrConditional(int condition) final;
-			void ret() final;
+			void jr(int8_t offset) noexcept final;
+			int jumpConditional(int condition) noexcept final;
+			int returnConditional(int condition) noexcept final;
+			int jrConditional(int condition) noexcept final;
+			void ret() noexcept final;
 
 		private:
 			Bus& m_bus;
diff --git a/LR35902/src/GameBoyBus.cpp b/LR35902/src/GameBoyBus.cpp
index b8b147f..a27e4dd 100644
--- a/LR35902/src/GameBoyBus.cpp
+++ b/LR35902/src/GameBoyBus.cpp
@@ -8,14 +8,14 @@ EightBit::GameBoy::Bus::Bus() noexcept
 	WrittenByte.connect(std::bind(&GameBoy::Bus::Bus_WrittenByte, this, std::placeholders::_1));
 }
 
-void EightBit::GameBoy::Bus::raisePOWER() {
+void EightBit::GameBoy::Bus::raisePOWER() noexcept {
 	EightBit::Bus::raisePOWER();
 	CPU().raisePOWER();
 	CPU().raiseINT();
 	reset();
 }
 
-void EightBit::GameBoy::Bus::lowerPOWER() {
+void EightBit::GameBoy::Bus::lowerPOWER() noexcept {
 	CPU().lowerPOWER();
 	EightBit::Bus::lowerPOWER();
 }
diff --git a/LR35902/src/LR35902.cpp b/LR35902/src/LR35902.cpp
index 50a7b0c..5149742 100644
--- a/LR35902/src/LR35902.cpp
+++ b/LR35902/src/LR35902.cpp
@@ -31,59 +31,59 @@ const EightBit::register16_t& EightBit::GameBoy::LR35902::HL() const noexcept {
 	return hl;
 }
 
-void EightBit::GameBoy::LR35902::handleRESET() {
+void EightBit::GameBoy::LR35902::handleRESET() noexcept {
 	IntelProcessor::handleRESET();
 	di();
 	SP() = Mask16 - 1;
 	tickMachine(4);
 }
 
-void EightBit::GameBoy::LR35902::handleINT() {
+void EightBit::GameBoy::LR35902::handleINT() noexcept {
 	IntelProcessor::handleINT();
 	raiseHALT();
 	di();
 	restart(BUS().DATA());
 }
 
-void EightBit::GameBoy::LR35902::memoryWrite() {
+void EightBit::GameBoy::LR35902::memoryWrite() noexcept {
 	tickMachine();
 	IntelProcessor::memoryWrite();
 }
 
-uint8_t EightBit::GameBoy::LR35902::memoryRead() {
+uint8_t EightBit::GameBoy::LR35902::memoryRead() noexcept {
 	tickMachine();
 	return IntelProcessor::memoryRead();
 }
 
-void EightBit::GameBoy::LR35902::pushWord(register16_t value) {
+void EightBit::GameBoy::LR35902::pushWord(register16_t value) noexcept {
 	tickMachine();
 	IntelProcessor::pushWord(value);
 }
 
-void EightBit::GameBoy::LR35902::jr(int8_t offset) {
+void EightBit::GameBoy::LR35902::jr(int8_t offset) noexcept {
 	IntelProcessor::jr(offset);
 	tickMachine();
 }
 
-int EightBit::GameBoy::LR35902::jumpConditional(const int condition) {
+int EightBit::GameBoy::LR35902::jumpConditional(const int condition) noexcept {
 	if (IntelProcessor::jumpConditional(condition))
 		tickMachine();
 	return condition;
 }
 
-int EightBit::GameBoy::LR35902::returnConditional(const int condition) {
+int EightBit::GameBoy::LR35902::returnConditional(const int condition) noexcept {
 	IntelProcessor::returnConditional(condition);
 	tickMachine();
 	return condition;
 }
 
-int EightBit::GameBoy::LR35902::jrConditional(const int condition) {
+int EightBit::GameBoy::LR35902::jrConditional(const int condition) noexcept {
 	if (!IntelProcessor::jrConditional(condition))
 		tickMachine();
 	return condition;
 }
 
-void EightBit::GameBoy::LR35902::ret() {
+void EightBit::GameBoy::LR35902::ret() noexcept {
 	IntelProcessor::ret();
 	tickMachine();
 }
@@ -435,7 +435,7 @@ uint8_t EightBit::GameBoy::LR35902::maskedInterrupts() noexcept {
 	return enabledInterrupts() & flaggedInterrupts();
 }
 
-int EightBit::GameBoy::LR35902::step() {
+int EightBit::GameBoy::LR35902::step() noexcept {
 
 	ExecutingInstruction.fire(*this);
 	m_prefixCB = false;
@@ -470,7 +470,7 @@ int EightBit::GameBoy::LR35902::step() {
 	return cycles();
 }
 
-int EightBit::GameBoy::LR35902::execute() {
+int EightBit::GameBoy::LR35902::execute() noexcept {
 
 	const auto& decoded = getDecodedOpcode(opcode());
 
@@ -486,8 +486,7 @@ int EightBit::GameBoy::LR35902::execute() {
 	else
 		executeCB(x, y, z, p, q);
 
-	if (UNLIKELY(cycles() == 0))
-		throw std::logic_error("Unhandled opcode");
+	assert(cycles() > 0);
 
 	return cycles();
 }
@@ -802,14 +801,14 @@ void EightBit::GameBoy::LR35902::executeOther(const int x, const int y, const in
 				IntelProcessor::memoryWrite(IoRegisters::BASE + C(), A());
 				break;
 			case 5:	// GB: LD (nn),A
-				BUS().ADDRESS() = MEMPTR() = fetchWord();
-				IntelProcessor::memoryWrite(A());
+				MEMPTR() = BUS().ADDRESS() = fetchWord();
+					IntelProcessor::memoryWrite(A());
 				break;
 			case 6:	// GB: LD A,(FF00 + C)
 				A() = IntelProcessor::memoryRead(IoRegisters::BASE + C());
 				break;
 			case 7:	// GB: LD A,(nn)
-				BUS().ADDRESS() = MEMPTR() = fetchWord();
+				MEMPTR() = BUS().ADDRESS() = fetchWord();
 				A() = memoryRead();
 				break;
 			default:
diff --git a/M6502/HarteTest_6502/TestRunner.cpp b/M6502/HarteTest_6502/TestRunner.cpp
index 15117d6..f175339 100644
--- a/M6502/HarteTest_6502/TestRunner.cpp
+++ b/M6502/HarteTest_6502/TestRunner.cpp
@@ -7,7 +7,7 @@ EightBit::MemoryMapping TestRunner::mapping(const uint16_t address) noexcept {
     return { RAM(), 0x0000, 0xffff, EightBit::MemoryMapping::AccessLevel::ReadWrite };
 }
 
-void TestRunner::raisePOWER() {
+void TestRunner::raisePOWER() noexcept {
     EightBit::Bus::raisePOWER();
     CPU().raisePOWER();
     CPU().raiseRESET();
@@ -17,7 +17,7 @@ void TestRunner::raisePOWER() {
     CPU().raiseRDY();
 }
 
-void TestRunner::lowerPOWER() {
+void TestRunner::lowerPOWER() noexcept {
     CPU().lowerPOWER();
     EightBit::Bus::lowerPOWER();
 }
diff --git a/M6502/HarteTest_6502/TestRunner.h b/M6502/HarteTest_6502/TestRunner.h
index 2bc2a01..874aed8 100644
--- a/M6502/HarteTest_6502/TestRunner.h
+++ b/M6502/HarteTest_6502/TestRunner.h
@@ -15,8 +15,8 @@ protected:
 public:
     TestRunner();
 
-    void raisePOWER() final;
-    void lowerPOWER() final;
+    void raisePOWER() noexcept final;
+    void lowerPOWER() noexcept final;
 
     void initialise() final;
 
diff --git a/M6502/inc/mos6502.h b/M6502/inc/mos6502.h
index f1e05dd..20ac98f 100644
--- a/M6502/inc/mos6502.h
+++ b/M6502/inc/mos6502.h
@@ -38,8 +38,8 @@ namespace EightBit {
 		Signal<MOS6502> ExecutingInstruction;
 		Signal<MOS6502> ExecutedInstruction;
 
-		int execute() final;
-		[[nodiscard]] int step() final;
+		int execute() noexcept final;
+		[[nodiscard]] int step() noexcept final;
 
 		[[nodiscard]] constexpr auto& X() noexcept { return x; }
 		[[nodiscard]] constexpr auto& Y() noexcept { return y; }
@@ -50,11 +50,11 @@ namespace EightBit {
 		[[nodiscard]] constexpr const auto& P() const noexcept { return p; }
 
 	protected:
-		void handleRESET() final;
-		void handleINT() final;
+		void handleRESET() noexcept final;
+		void handleINT() noexcept final;
 
-		void busWrite() final;
-		[[nodiscard]] uint8_t busRead() final;
+		void busWrite() noexcept final;
+		[[nodiscard]] uint8_t busRead() noexcept final;
 
 		[[nodiscard]] virtual uint8_t sub(uint8_t operand, uint8_t data, int borrow = 0) noexcept;
 		[[nodiscard]] uint8_t sbc(uint8_t operand, uint8_t data) noexcept;
@@ -71,16 +71,16 @@ namespace EightBit {
 		const uint8_t RSTvector = 0xfc;		// RST vector
 		const uint8_t NMIvector = 0xfa;		// NMI vector
 
-		void handleNMI();
-		void handleSO();
+		void handleNMI() noexcept;
+		void handleSO() noexcept;
 
 		void interrupt();
 
-		void push(uint8_t value) final;
-		[[nodiscard]] uint8_t pop() final;
+		void push(uint8_t value) noexcept final;
+		[[nodiscard]] uint8_t pop() noexcept final;
 
 		// Dummy stack push, used during RESET
-		void dummyPush(uint8_t value);
+		void dummyPush(uint8_t value) noexcept;
 
 		// Addressing modes
 
diff --git a/M6502/src/mos6502.cpp b/M6502/src/mos6502.cpp
index 465727c..fac850b 100644
--- a/M6502/src/mos6502.cpp
+++ b/M6502/src/mos6502.cpp
@@ -20,7 +20,7 @@ DEFINE_PIN_LEVEL_CHANGERS(SYNC, MOS6502);
 DEFINE_PIN_LEVEL_CHANGERS(RDY, MOS6502);
 DEFINE_PIN_LEVEL_CHANGERS(RW, MOS6502);
 
-int EightBit::MOS6502::step() {
+int EightBit::MOS6502::step() noexcept {
 	resetCycles();
 	ExecutingInstruction.fire(*this);
 	if (LIKELY(powered())) {
@@ -46,25 +46,25 @@ int EightBit::MOS6502::step() {
 
 // Interrupt (etc.) handlers
 
-void EightBit::MOS6502::handleSO() {
+void EightBit::MOS6502::handleSO() noexcept {
 	raiseSO();
 	P() |= VF;
 }
 
-void EightBit::MOS6502::handleRESET() {
+void EightBit::MOS6502::handleRESET() noexcept {
 	raiseRESET();
 	m_handlingRESET = true;
 	opcode() = 0x00;	// BRK
 }
 
 
-void EightBit::MOS6502::handleNMI() {
+void EightBit::MOS6502::handleNMI() noexcept {
 	raiseNMI();
 	m_handlingNMI = true;
 	opcode() = 0x00;	// BRK
 }
 
-void EightBit::MOS6502::handleINT() {
+void EightBit::MOS6502::handleINT() noexcept {
 	raiseINT();
 	m_handlingINT = true;
 	opcode() = 0x00;	// BRK
@@ -92,13 +92,13 @@ void EightBit::MOS6502::interrupt() {
 
 //
 
-void EightBit::MOS6502::busWrite() {
+void EightBit::MOS6502::busWrite() noexcept {
 	tick();
 	lowerRW();
 	Processor::busWrite();
 }
 
-uint8_t EightBit::MOS6502::busRead() {
+uint8_t EightBit::MOS6502::busRead() noexcept {
 	tick();
 	raiseRW();
 	return Processor::busRead();
@@ -106,7 +106,7 @@ uint8_t EightBit::MOS6502::busRead() {
 
 //
 
-int EightBit::MOS6502::execute() { 
+int EightBit::MOS6502::execute() noexcept {
 
 	raiseSYNC();	// Instruction fetch has now completed
 
@@ -391,15 +391,15 @@ int EightBit::MOS6502::execute() {
 
 ////
 
-void EightBit::MOS6502::push(uint8_t value) {
+void EightBit::MOS6502::push(uint8_t value) noexcept {
 	setBytePaged(1, S()--, value);
 }
 
-uint8_t EightBit::MOS6502::pop() {
+uint8_t EightBit::MOS6502::pop() noexcept {
 	return getBytePaged(1, ++S());
 }
 
-void EightBit::MOS6502::dummyPush(const uint8_t value) {
+void EightBit::MOS6502::dummyPush(const uint8_t value) noexcept {
 	tick();
 	BUS().DATA() = value;
 	BUS().ADDRESS() = { S()--, 1 };
diff --git a/M6502/test/Board.cpp b/M6502/test/Board.cpp
index 6ed4310..b0c15aa 100644
--- a/M6502/test/Board.cpp
+++ b/M6502/test/Board.cpp
@@ -10,7 +10,7 @@
 Board::Board(const Configuration& configuration)
 : m_configuration(configuration) {}
 
-void Board::raisePOWER() {
+void Board::raisePOWER() noexcept {
 	EightBit::Bus::raisePOWER();
 	CPU().raisePOWER();
 	CPU().raiseRESET();
@@ -20,7 +20,7 @@ void Board::raisePOWER() {
 	CPU().raiseRDY();
 }
 
-void Board::lowerPOWER() {
+void Board::lowerPOWER() noexcept {
 	CPU().lowerPOWER();
 	EightBit::Bus::lowerPOWER();
 }
diff --git a/M6502/test/Board.h b/M6502/test/Board.h
index 8d8b09d..260b82b 100644
--- a/M6502/test/Board.h
+++ b/M6502/test/Board.h
@@ -17,10 +17,10 @@ public:
 
 	EightBit::MOS6502& CPU() { return m_cpu; }
 
-	virtual void raisePOWER() final;
-	virtual void lowerPOWER() final;
+	void raisePOWER() noexcept final;
+	void lowerPOWER() noexcept final;
 
-	virtual void initialise() final;
+	void initialise() final;
 
 protected:
 	virtual EightBit::MemoryMapping mapping(uint16_t address) noexcept final {
diff --git a/MC6809/inc/mc6809.h b/MC6809/inc/mc6809.h
index 6763a75..d5ade08 100644
--- a/MC6809/inc/mc6809.h
+++ b/MC6809/inc/mc6809.h
@@ -66,8 +66,8 @@ namespace EightBit {
 		Signal<mc6809> ExecutingInstruction;
 		Signal<mc6809> ExecutedInstruction;
 
-		int execute() final;
-		[[nodiscard]] int step() final;
+		int execute() noexcept final;
+		[[nodiscard]] int step() noexcept final;
 
 		[[nodiscard]] constexpr auto& D() noexcept { return m_d; }
 		[[nodiscard]] constexpr auto& A() noexcept { return D().high; }
@@ -111,21 +111,21 @@ namespace EightBit {
 	protected:
 		// Default push/pop handlers
 
-		void push(uint8_t value) final;
-		[[nodiscard]] uint8_t pop() final;
+		void push(uint8_t value) noexcept final;
+		[[nodiscard]] uint8_t pop() noexcept final;
 
 		// Interrupt (etc.) handlers
 
-		void handleRESET() final;
-		void handleINT() final;
+		void handleRESET() noexcept final;
+		void handleINT() noexcept final;
 
 		// Bus reader/writers
 
-		void busWrite() final;
-		uint8_t busRead() final;
+		void busWrite() noexcept final;
+		uint8_t busRead() noexcept final;
 
-		void call(register16_t destination) final;
-		void ret() final;
+		void call(register16_t destination) noexcept final;
+		void ret() noexcept final;
 
 	private:
 		const uint8_t RESETvector = 0xfe;		// RESET vector
diff --git a/MC6809/src/mc6809.cpp b/MC6809/src/mc6809.cpp
index ba067d8..9aa780e 100644
--- a/MC6809/src/mc6809.cpp
+++ b/MC6809/src/mc6809.cpp
@@ -20,7 +20,7 @@ DEFINE_PIN_LEVEL_CHANGERS(BA, mc6809);
 DEFINE_PIN_LEVEL_CHANGERS(BS, mc6809);
 DEFINE_PIN_LEVEL_CHANGERS(RW, mc6809);
 
-int EightBit::mc6809::step() {
+int EightBit::mc6809::step() noexcept {
 	resetCycles();
 	ExecutingInstruction.fire(*this);
 	if (LIKELY(powered())) {
@@ -49,7 +49,7 @@ void EightBit::mc6809::handleHALT() {
 	raiseBS();
 }
 
-void EightBit::mc6809::handleRESET() {
+void EightBit::mc6809::handleRESET() noexcept {
 	BigEndianProcessor::handleRESET();
 	memoryRead({ RESETvector, 0xff });
 	raiseNMI();
@@ -80,7 +80,7 @@ void EightBit::mc6809::handleNMI() {
 	eat();
 }
 
-void EightBit::mc6809::handleINT() {
+void EightBit::mc6809::handleINT() noexcept {
 	BigEndianProcessor::handleINT();
 	lowerBA();
 	raiseBS();
@@ -111,13 +111,13 @@ void EightBit::mc6809::handleFIRQ() {
 
 //
 
-void EightBit::mc6809::busWrite() {
+void EightBit::mc6809::busWrite() noexcept {
 	tick();
 	lowerRW();
 	Processor::busWrite();
 }
 
-uint8_t EightBit::mc6809::busRead() {
+uint8_t EightBit::mc6809::busRead() noexcept {
 	tick();
 	raiseRW();
 	return Processor::busRead();
@@ -125,21 +125,21 @@ uint8_t EightBit::mc6809::busRead() {
 
 //
 
-void EightBit::mc6809::call(register16_t destination) {
+void EightBit::mc6809::call(register16_t destination) noexcept {
 	memoryRead(destination);
 	eat();
 	BigEndianProcessor::pushWord(PC());
 	jump(destination);
 }
 
-void EightBit::mc6809::ret() {
+void EightBit::mc6809::ret() noexcept {
 	BigEndianProcessor::ret();
 	eat();
 }
 
 //
 
-int EightBit::mc6809::execute() {
+int EightBit::mc6809::execute() noexcept {
 	lowerBA();
 	lowerBS();
 	const bool prefixed = m_prefix10 || m_prefix11;
@@ -628,11 +628,11 @@ void EightBit::mc6809::execute11() {
 
 //
 
-void EightBit::mc6809::push(const uint8_t value) {
+void EightBit::mc6809::push(const uint8_t value) noexcept {
 	pushS(value);
 }
 
-uint8_t EightBit::mc6809::pop() {
+uint8_t EightBit::mc6809::pop() noexcept {
 	return popS();
 }
 
diff --git a/MC6809/test/Board.cpp b/MC6809/test/Board.cpp
index 30c5c24..bd1a814 100644
--- a/MC6809/test/Board.cpp
+++ b/MC6809/test/Board.cpp
@@ -4,7 +4,7 @@
 Board::Board(const Configuration& configuration)
 : m_configuration(configuration) {}
 
-void Board::raisePOWER() {
+void Board::raisePOWER() noexcept {
 
 	EightBit::Bus::raisePOWER();
 
@@ -26,7 +26,7 @@ void Board::raisePOWER() {
 	accessAcia();
 }
 
-void Board::lowerPOWER() {
+void Board::lowerPOWER() noexcept {
 
 	if (m_configuration.isProfileMode()) {
 		m_profiler.EmitLine.connect([this](EightBit::ProfileLineEventArgs line) {
diff --git a/MC6809/test/Board.h b/MC6809/test/Board.h
index 8763a28..4eb68a2 100644
--- a/MC6809/test/Board.h
+++ b/MC6809/test/Board.h
@@ -20,8 +20,8 @@ public:
 	auto& CPU() { return m_cpu; }
 	auto& ACIA() { return m_acia; }
 
-	void raisePOWER() final;
-	void lowerPOWER() final;
+	void raisePOWER() noexcept final;
+	void lowerPOWER() noexcept final;
 
 	virtual void initialise() final;
 
diff --git a/MC6809/unittest/Board.cpp b/MC6809/unittest/Board.cpp
index 3e43d95..d1219ff 100644
--- a/MC6809/unittest/Board.cpp
+++ b/MC6809/unittest/Board.cpp
@@ -3,7 +3,7 @@
 
 Board::Board() {}
 
-void Board::raisePOWER() {
+void Board::raisePOWER() noexcept {
 	EightBit::Bus::raisePOWER();
 
 	CPU().raisePOWER();
@@ -16,7 +16,7 @@ void Board::raisePOWER() {
 	CPU().raiseHALT();
 }
 
-void Board::lowerPOWER() {
+void Board::lowerPOWER() noexcept {
 	CPU().lowerPOWER();
 	EightBit::Bus::lowerPOWER();
 }
diff --git a/MC6809/unittest/Board.h b/MC6809/unittest/Board.h
index 535cf3c..f7d405a 100644
--- a/MC6809/unittest/Board.h
+++ b/MC6809/unittest/Board.h
@@ -11,8 +11,8 @@ public:
 
 	constexpr EightBit::mc6809& CPU() noexcept { return m_cpu; }
 
-	void raisePOWER() final;
-	void lowerPOWER() final;
+	void raisePOWER() noexcept final;
+	void lowerPOWER() noexcept final;
 
 protected:
 	void initialise() final;
diff --git a/Z80/fusetest_Z80/FuseExpectedTestResult.cpp b/Z80/fusetest_Z80/FuseExpectedTestResult.cpp
index bc25428..676731a 100644
--- a/Z80/fusetest_Z80/FuseExpectedTestResult.cpp
+++ b/Z80/fusetest_Z80/FuseExpectedTestResult.cpp
@@ -45,4 +45,15 @@ void Fuse::ExpectedTestResult::read(std::ifstream& file) {
 			memoryData.push_back(datum);
 		}
 	} while (!line.empty());
-}
\ No newline at end of file
+}
+
+// returns a vector of: address, expected, actual
+std::vector<std::tuple<int, int, int>> Fuse::ExpectedTestResult::findDifferences(const EightBit::Memory& memory) const {
+	std::vector<std::tuple<int, int, int>> returned;
+	for (const auto& memoryDatum : memoryData) {
+		const auto found = memoryDatum.findDifferences(memory);
+		if (!found.empty())
+			returned.insert(returned.end(), found.begin(), found.end());
+	}
+	return returned;
+}
diff --git a/Z80/fusetest_Z80/FuseExpectedTestResult.h b/Z80/fusetest_Z80/FuseExpectedTestResult.h
index 29bf4ee..ff33567 100644
--- a/Z80/fusetest_Z80/FuseExpectedTestResult.h
+++ b/Z80/fusetest_Z80/FuseExpectedTestResult.h
@@ -3,6 +3,7 @@
 #include <fstream>
 #include <string>
 #include <vector>
+#include <tuple>
 
 #include "FuseTestEvents.h"
 #include "FuseRegisterState.h"
@@ -23,5 +24,8 @@ namespace Fuse {
 		: finish(false) {}
 
 		void read(std::ifstream& file);
+
+		// returns a vector of: address, expected, actual
+		std::vector<std::tuple<int, int, int>> findDifferences(const EightBit::Memory& memory) const;
 	};
 }
\ No newline at end of file
diff --git a/Z80/fusetest_Z80/FuseMemoryDatum.cpp b/Z80/fusetest_Z80/FuseMemoryDatum.cpp
index 871e8ef..e55d408 100644
--- a/Z80/fusetest_Z80/FuseMemoryDatum.cpp
+++ b/Z80/fusetest_Z80/FuseMemoryDatum.cpp
@@ -17,4 +17,21 @@ void Fuse::MemoryDatum::read(std::ifstream& file) {
 		if (!completed)
 			bytes.push_back(byte);
 	} while (!completed);
-}
\ No newline at end of file
+}
+
+void Fuse::MemoryDatum::transfer(EightBit::Memory& memory) const {
+	memory.load(bytes, address);
+}
+
+// returns a vector of: address, expected, actual
+std::vector<std::tuple<int, int, int>> Fuse::MemoryDatum::findDifferences(const EightBit::Memory& memory) const {
+	std::vector<std::tuple<int, int, int>> returned;
+	for (int i = 0; i < bytes.size(); ++i) {
+		const auto expected = bytes[i];
+		int address = this->address + i;
+		const auto actual = memory.peek(address);
+		if (expected != actual)
+			returned.push_back({ address, expected, actual });
+	}
+	return returned;;
+}
diff --git a/Z80/fusetest_Z80/FuseMemoryDatum.h b/Z80/fusetest_Z80/FuseMemoryDatum.h
index 0cf4c33..0a6ac77 100644
--- a/Z80/fusetest_Z80/FuseMemoryDatum.h
+++ b/Z80/fusetest_Z80/FuseMemoryDatum.h
@@ -3,6 +3,9 @@
 #include <cinttypes>
 #include <vector>
 #include <fstream>
+#include <tuple>
+
+#include <Memory.h>
 
 namespace Fuse {
 	class MemoryDatum {
@@ -19,5 +22,10 @@ namespace Fuse {
 
 		bool finished() const { return finish; }
 		void read(std::ifstream& file);
+
+		void transfer(EightBit::Memory& memory) const;
+
+		// returns a vector of: address, expected, actual
+		std::vector<std::tuple<int, int, int>> findDifferences(const EightBit::Memory& memory) const;
 	};
 }
\ No newline at end of file
diff --git a/Z80/fusetest_Z80/FuseRegisterState.cpp b/Z80/fusetest_Z80/FuseRegisterState.cpp
index b0e3db3..430ddad 100644
--- a/Z80/fusetest_Z80/FuseRegisterState.cpp
+++ b/Z80/fusetest_Z80/FuseRegisterState.cpp
@@ -1,6 +1,8 @@
 #include "stdafx.h"
 #include "FuseRegisterState.h"
 
+#include <Z80.h>
+
 Fuse::RegisterState::RegisterState()
 : registers(NUMBER_OF_REGISTERS) {
 }
@@ -11,10 +13,10 @@ void Fuse::RegisterState::read(std::ifstream& file) {
 }
 
 void Fuse::RegisterState::readExternal(std::ifstream& file) {
-	for (int idx = 0; idx < registers.size(); ++idx) {
+	for (auto& r : registers) {
 		int input;
 		file >> input;
-		registers[idx] = input;
+		r = input;
 	}
 }
 
@@ -30,3 +32,31 @@ void Fuse::RegisterState::readInternal(std::ifstream& file) {
 	file >> tstates;
 	file >> std::hex;
 }
+
+void Fuse::RegisterState::transfer(EightBit::Z80& cpu) const {
+
+	cpu.AF() = registers[AF_];
+	cpu.BC() = registers[BC_];
+	cpu.DE() = registers[DE_];
+	cpu.HL() = registers[HL_];
+	cpu.exx();
+	cpu.exxAF();
+	cpu.AF() = registers[AF];
+	cpu.BC() = registers[BC];
+	cpu.DE() = registers[DE];
+	cpu.HL() = registers[HL];
+
+	cpu.IX() = registers[IX];
+	cpu.IY() = registers[IY];
+
+	cpu.SP() = registers[SP];
+	cpu.PC() = registers[PC];
+
+	cpu.MEMPTR() = registers[MEMPTR];
+
+	cpu.IV() = i;
+	cpu.REFRESH() = r;
+	cpu.IFF1() = iff1;
+	cpu.IFF2() = iff2;
+	cpu.IM() = im;
+}
diff --git a/Z80/fusetest_Z80/FuseRegisterState.h b/Z80/fusetest_Z80/FuseRegisterState.h
index 70d4a96..a25d6c2 100644
--- a/Z80/fusetest_Z80/FuseRegisterState.h
+++ b/Z80/fusetest_Z80/FuseRegisterState.h
@@ -1,11 +1,14 @@
 #pragma once
 
 #include <vector>
-#include <string>
 #include <fstream>
 
 #include <Register.h>
 
+namespace EightBit {
+	class Z80;
+}
+
 namespace Fuse {
 	class RegisterState {
 	public:
@@ -13,11 +16,11 @@ namespace Fuse {
 			AF, BC, DE, HL, AF_, BC_, DE_, HL_, IX, IY, SP, PC, MEMPTR, NUMBER_OF_REGISTERS
 		};
 		std::vector<EightBit::register16_t> registers;
-		int i, r;
-		bool iff1, iff2;
-		int im;
-		bool halted;
-		int tstates;
+		int i = -1, r = -1;
+		bool iff1 = false, iff2 = false;
+		int im = -1;
+		bool halted = false;
+		int tstates = -1;
 
 	public:
 		RegisterState();
@@ -25,5 +28,7 @@ namespace Fuse {
 		void read(std::ifstream& file);
 		void readInternal(std::ifstream& file);
 		void readExternal(std::ifstream& file);
+
+		void transfer(EightBit::Z80& cpu) const;
 	};
 }
\ No newline at end of file
diff --git a/Z80/fusetest_Z80/FuseTest.cpp b/Z80/fusetest_Z80/FuseTest.cpp
index 1a8ca4a..c991325 100644
--- a/Z80/fusetest_Z80/FuseTest.cpp
+++ b/Z80/fusetest_Z80/FuseTest.cpp
@@ -23,3 +23,12 @@ void Fuse::Test::read(std::ifstream& file) {
 			memoryData.push_back(memoryDatum);
 	} while (!complete);
 }
+
+void Fuse::Test::transferMemory(EightBit::Memory& memory) const {
+	for (const auto& memoryDatum : memoryData)
+		memoryDatum.transfer(memory);
+}
+
+void Fuse::Test::transferRegisters(EightBit::Z80 & cpu) const {
+	registerState.transfer(cpu);
+}
diff --git a/Z80/fusetest_Z80/FuseTest.h b/Z80/fusetest_Z80/FuseTest.h
index 35aa4cd..ca763f4 100644
--- a/Z80/fusetest_Z80/FuseTest.h
+++ b/Z80/fusetest_Z80/FuseTest.h
@@ -7,6 +7,9 @@
 #include "FuseMemoryDatum.h"
 #include "FuseRegisterState.h"
 
+#include <Memory.h>
+#include <Z80.h>
+
 namespace Fuse {
 	class Test {
 	public:
@@ -16,5 +19,8 @@ namespace Fuse {
 		bool finish = false;
 
 		void read(std::ifstream& file);
+
+		void transferMemory(EightBit::Memory& memory) const;
+		void transferRegisters(EightBit::Z80& cpu) const;
 	};
 }
\ No newline at end of file
diff --git a/Z80/fusetest_Z80/FuseTestEvent.cpp b/Z80/fusetest_Z80/FuseTestEvent.cpp
index 57cc271..c49fc69 100644
--- a/Z80/fusetest_Z80/FuseTestEvent.cpp
+++ b/Z80/fusetest_Z80/FuseTestEvent.cpp
@@ -1,6 +1,18 @@
 #include "stdafx.h"
 #include "FuseTestEvent.h"
 
+#include <boost/algorithm/string/predicate.hpp>
+
+#include <Disassembler.h>
+
+bool Fuse::TestEvent::operator==(const TestEvent& rhs) const {
+	const auto equalCycles = cycles == rhs.cycles;
+	const auto equalSpecifier = specifier == rhs.specifier;
+	const auto equalAddress = address == rhs.address;
+	const auto equalValue = value == rhs.value;
+	return equalCycles && equalSpecifier && equalAddress && equalValue;
+}
+
 void Fuse::TestEvent::read(std::ifstream& file) {
 
 	auto prior = file.tellg();
@@ -31,4 +43,14 @@ void Fuse::TestEvent::read(std::ifstream& file) {
 	if (!valid) {
 		file.seekg(prior);
 	}
+}
+
+void Fuse::TestEvent::dump() const {
+	std::cerr << " Event issue " <<
+		"Cycles = " << cycles <<
+		", Specifier = " << specifier <<
+		", Address = " << EightBit::Disassembler::hex((uint16_t)address);
+	if (!boost::algorithm::ends_with(specifier, "C"))
+		std::cerr << ", Value=" << EightBit::Disassembler::hex((uint8_t)value);
+	std::cerr << std::endl;
 }
\ No newline at end of file
diff --git a/Z80/fusetest_Z80/FuseTestEvent.h b/Z80/fusetest_Z80/FuseTestEvent.h
index 8ea1c65..f65fb4c 100644
--- a/Z80/fusetest_Z80/FuseTestEvent.h
+++ b/Z80/fusetest_Z80/FuseTestEvent.h
@@ -12,9 +12,12 @@ namespace Fuse {
 
 		TestEvent() 
 		: valid(false),
-		  cycles(-1), address(-1), value(-1) {
-		}
+		  cycles(-1), address(-1), value(-1) {}
+
+		bool operator==(const TestEvent& rhs) const;
 
 		void read(std::ifstream& file);
+
+		void dump() const;
 	};
 }
\ No newline at end of file
diff --git a/Z80/fusetest_Z80/FuseTestEvents.cpp b/Z80/fusetest_Z80/FuseTestEvents.cpp
index 081393b..a3e1788 100644
--- a/Z80/fusetest_Z80/FuseTestEvents.cpp
+++ b/Z80/fusetest_Z80/FuseTestEvents.cpp
@@ -1,6 +1,15 @@
 #include "stdafx.h"
 #include "FuseTestEvents.h"
 
+bool Fuse::TestEvents::operator==(const TestEvents& rhs) const {
+	auto unequal = events.size() != rhs.events.size();
+	for (int i = 0; !unequal && (i < events.size()); ++i) {
+		const auto equal = events[i] == rhs.events[i];
+		unequal = !equal;
+	}
+	return !unequal;
+}
+
 void Fuse::TestEvents::read(std::ifstream& file) {
 	bool complete = false;
 	do {
@@ -11,3 +20,8 @@ void Fuse::TestEvents::read(std::ifstream& file) {
 			events.push_back(event);
 	}  while (!complete);
 }
+
+void Fuse::TestEvents::dump() const {
+	for (const auto& event : events)
+		event.dump();
+}
diff --git a/Z80/fusetest_Z80/FuseTestEvents.h b/Z80/fusetest_Z80/FuseTestEvents.h
index 9463cdb..0ef4bfa 100644
--- a/Z80/fusetest_Z80/FuseTestEvents.h
+++ b/Z80/fusetest_Z80/FuseTestEvents.h
@@ -8,6 +8,10 @@ namespace Fuse {
 	public:
 		std::vector<TestEvent> events;
 
+		bool operator==(const TestEvents& rhs) const;
+
 		void read(std::ifstream& file);
+
+		void dump() const;
 	};
 }
\ No newline at end of file
diff --git a/Z80/fusetest_Z80/FuseTestRunner.cpp b/Z80/fusetest_Z80/FuseTestRunner.cpp
index 3c3ede0..156b432 100644
--- a/Z80/fusetest_Z80/FuseTestRunner.cpp
+++ b/Z80/fusetest_Z80/FuseTestRunner.cpp
@@ -51,16 +51,16 @@ void Fuse::TestRunner::addActualEvent(const std::string& specifier) {
 
 //
 
-void Fuse::TestRunner::raisePOWER() {
+void Fuse::TestRunner::raisePOWER() noexcept {
 	EightBit::Bus::raisePOWER();
 	m_cpu.raisePOWER();
 	m_cpu.raiseRESET();
 	m_cpu.raiseINT();
 	m_cpu.raiseNMI();
-	initialiseRegisters();
+	m_test.transferRegisters(m_cpu);
 }
 
-void Fuse::TestRunner::lowerPOWER() {
+void Fuse::TestRunner::lowerPOWER() noexcept {
 	m_cpu.lowerPOWER();
 	EightBit::Bus::lowerPOWER();
 }
@@ -99,47 +99,7 @@ EightBit::MemoryMapping Fuse::TestRunner::mapping(uint16_t address) noexcept {
 }
 
 void Fuse::TestRunner::initialise() {
-	initialiseMemory();
-}
-
-void Fuse::TestRunner::initialiseRegisters() {
-
-	const auto& testState = m_test.registerState;
-	const auto& inputRegisters = testState.registers;
-
-	m_cpu.AF() = inputRegisters[Fuse::RegisterState::AF_];
-	m_cpu.BC() = inputRegisters[Fuse::RegisterState::BC_];
-	m_cpu.DE() = inputRegisters[Fuse::RegisterState::DE_];
-	m_cpu.HL() = inputRegisters[Fuse::RegisterState::HL_];
-	m_cpu.exx();
-	m_cpu.exxAF();
-	m_cpu.AF() = inputRegisters[Fuse::RegisterState::AF];
-	m_cpu.BC() = inputRegisters[Fuse::RegisterState::BC];
-	m_cpu.DE() = inputRegisters[Fuse::RegisterState::DE];
-	m_cpu.HL() = inputRegisters[Fuse::RegisterState::HL];
-
-	m_cpu.IX() = inputRegisters[Fuse::RegisterState::IX];
-	m_cpu.IY() = inputRegisters[Fuse::RegisterState::IY];
-
-	m_cpu.SP() = inputRegisters[Fuse::RegisterState::SP];
-	m_cpu.PC() = inputRegisters[Fuse::RegisterState::PC];
-
-	m_cpu.MEMPTR() = inputRegisters[Fuse::RegisterState::MEMPTR];
-
-	m_cpu.IV() = testState.i;
-	m_cpu.REFRESH() = testState.r;
-	m_cpu.IFF1() = testState.iff1;
-	m_cpu.IFF2() = testState.iff2;
-	m_cpu.IM() = testState.im;
-}
-
-void Fuse::TestRunner::initialiseMemory() {
-	for (auto memoryDatum : m_test.memoryData) {
-		auto address = memoryDatum.address;
-		auto bytes = memoryDatum.bytes;
-		for (int i = 0; i < bytes.size(); ++i)
-			m_ram.poke(address + i, bytes[i]);
-	}
+	m_test.transferMemory(m_ram);
 }
 
 //
@@ -378,51 +338,26 @@ void Fuse::TestRunner::checkRegisters() {
 }
 
 void Fuse::TestRunner::checkMemory() {
-
-	bool first = true;
-
-	for (auto memoryDatum : m_result.memoryData) {
-		auto bytes = memoryDatum.bytes;
-		for (int i = 0; i < bytes.size(); ++i) {
-			auto expected = bytes[i];
-			uint16_t address = memoryDatum.address + i;
-			auto actual = m_ram.peek(address);
-			if (expected != actual) {
-				m_failed = true;
-				if (first) {
-					first = false;
-					std::cerr << "**** Failed test (Memory): " << m_test.description << std::endl;
-				}
-				std::cerr
-					<< "**** Difference: "
-					<< "Address: " << EightBit::Disassembler::hex(address)
-					<< " Expected: " << EightBit::Disassembler::hex(expected)
-					<< " Actual: " << EightBit::Disassembler::hex(actual)
-					<< std::endl;
-			}
+	const auto differences = m_result.findDifferences(m_ram);
+	const auto failure = !differences.empty();
+	if (failure) {
+		m_failed = true;
+		std::cerr << "**** Failed test (Memory): " << m_test.description << std::endl;
+		for (const auto& difference : differences) {
+			const auto [address, expected, actual] = difference;
+			std::cerr
+				<< "**** Difference: "
+				<< "Address: " << EightBit::Disassembler::hex((uint16_t)address)
+				<< " Expected: " << EightBit::Disassembler::hex((uint8_t)expected)
+				<< " Actual: " << EightBit::Disassembler::hex((uint8_t)actual)
+				<< std::endl;
 		}
 	}
 }
 
 void Fuse::TestRunner::checkEvents() {
 
-	const auto& expectations = m_expectedEvents.events;
-	const auto& actuals = m_actualEvents.events;
-
-	auto eventFailure = expectations.size() != actuals.size();
-	for (auto i = 0; !eventFailure && (i < expectations.size()); ++i) {
-
-		const auto& expectation = expectations[i];
-		const auto& actual = actuals[i];
-
-		const auto equalCycles = expectation.cycles == actual.cycles;
-		const auto equalSpecifier = expectation.specifier == actual.specifier;
-		const auto equalAddress = expectation.address == actual.address;
-		const auto equalValue = expectation.value == actual.value;
-
-		const auto equal = equalCycles && equalSpecifier && equalAddress && equalValue;
-		eventFailure = !equal;
-	}
+	auto eventFailure = m_expectedEvents != m_actualEvents;
 
 	if (eventFailure) {
 		dumpExpectedEvents();
@@ -435,28 +370,12 @@ void Fuse::TestRunner::checkEvents() {
 
 void Fuse::TestRunner::dumpExpectedEvents() const {
 	std::cerr << "++++ Dumping expected events:" << std::endl;
-	dumpEvents(m_expectedEvents.events);
+	m_expectedEvents.dump();
 }
 
 void Fuse::TestRunner::dumpActualEvents() const {
 	std::cerr << "++++ Dumping actual events:" << std::endl;
-	dumpEvents(m_actualEvents.events);
-}
-
-void Fuse::TestRunner::dumpEvents(const std::vector<TestEvent>& events) {
-	for (const auto& event : events) {
-		dumpEvent(event);
-	}
-}
-
-void Fuse::TestRunner::dumpEvent(const TestEvent& event) {
-	std::cerr << " Event issue " <<
-		"Cycles = " << event.cycles <<
-		", Specifier = " << event.specifier <<
-		", Address = " << EightBit::Disassembler::hex((uint16_t)event.address);
-	if (!boost::algorithm::ends_with(event.specifier, "C"))
-		std::cerr << ", Value=" << EightBit::Disassembler::hex((uint8_t)event.value);
-	std::cerr << std::endl;
+	m_actualEvents.dump();
 }
 
 void Fuse::TestRunner::run() {
diff --git a/Z80/fusetest_Z80/FuseTestRunner.h b/Z80/fusetest_Z80/FuseTestRunner.h
index 4ceba2f..e05b4e8 100644
--- a/Z80/fusetest_Z80/FuseTestRunner.h
+++ b/Z80/fusetest_Z80/FuseTestRunner.h
@@ -26,9 +26,6 @@ namespace Fuse {
 
 		int m_totalCycles;
 
-		void initialiseRegisters();
-		void initialiseMemory();
-
 		void check();
 		void checkRegisters();
 		void checkMemory();
@@ -44,9 +41,6 @@ namespace Fuse {
 		void dumpExpectedEvents() const;
 		void dumpActualEvents() const;
 
-		static void dumpEvents(const std::vector<TestEvent>& events);
-		static void dumpEvent(const TestEvent& event);
-
 	protected:
 		virtual EightBit::MemoryMapping mapping(uint16_t address) noexcept final;
 
@@ -57,9 +51,9 @@ namespace Fuse {
 		bool failed() const { return m_failed; }
 		bool unimplemented() const { return m_unimplemented; }
 
-		virtual void raisePOWER() final;
-		virtual void lowerPOWER() final;
+		void raisePOWER() noexcept final;
+		void lowerPOWER() noexcept final;
 
-		virtual void initialise() final;
+		void initialise() final;
 	};
 }
\ No newline at end of file
diff --git a/Z80/inc/Z80.h b/Z80/inc/Z80.h
index 8d6b6a8..524208b 100644
--- a/Z80/inc/Z80.h
+++ b/Z80/inc/Z80.h
@@ -89,8 +89,8 @@ namespace EightBit {
 		Signal<EventArgs> WritingIO;
 		Signal<EventArgs> WrittenIO;
 
-		int execute() final;
-		int step() final;
+		int execute() noexcept final;
+		int step() noexcept final;
 
 		[[nodiscard]] const register16_t& AF() const noexcept final;
 		[[nodiscard]] auto& AF() noexcept { return IntelProcessor::AF(); }
@@ -101,15 +101,15 @@ namespace EightBit {
 		[[nodiscard]] const register16_t& HL() const noexcept final;
 		[[nodiscard]] auto& HL() noexcept { return IntelProcessor::HL(); }
 
-		[[nodiscard]] const auto& IX() const noexcept { return m_ix; }
+		[[nodiscard]] constexpr const auto& IX() const noexcept { return m_ix; }
 		NON_CONST_REGISTOR_ACCESSOR(IX);
-		[[nodiscard]] auto& IXH() noexcept { return IX().high; }
-		[[nodiscard]] auto& IXL() noexcept { return IX().low; }
+		[[nodiscard]] constexpr auto& IXH() noexcept { return IX().high; }
+		[[nodiscard]] constexpr auto& IXL() noexcept { return IX().low; }
 
-		[[nodiscard]] const auto& IY() const noexcept { return m_iy; }
+		[[nodiscard]] constexpr const auto& IY() const noexcept { return m_iy; }
 		NON_CONST_REGISTOR_ACCESSOR(IY);
-		[[nodiscard]] auto& IYH() noexcept { return IY().high; }
-		[[nodiscard]] auto& IYL() noexcept { return IY().low; }
+		[[nodiscard]] constexpr auto& IYH() noexcept { return IY().high; }
+		[[nodiscard]] constexpr auto& IYL() noexcept { return IY().low; }
 
 		// ** From the Z80 CPU User Manual
 		// Memory Refresh(R) Register.The Z80 CPU contains a memory refresh counter,
@@ -144,19 +144,19 @@ namespace EightBit {
 		[[nodiscard]] constexpr auto requestingWrite() const noexcept { return lowered(WR()); }
 
 	protected:
-		void handleRESET() final;
-		void handleINT() final;
+		void handleRESET() noexcept final;
+		void handleINT() noexcept final;
 
-		void pushWord(register16_t destination) final;
+		void pushWord(register16_t destination) noexcept final;
 
-		void memoryWrite() final;
-		uint8_t memoryRead() final;
+		void memoryWrite() noexcept final;
+		uint8_t memoryRead() noexcept final;
 
-		void busWrite() final;
-		uint8_t busRead() final;
+		void busWrite() noexcept final;
+		uint8_t busRead() noexcept final;
 
-		void jr(int8_t offset) final;
-		int jrConditional(int condition) final;
+		void jr(int8_t offset) noexcept final;
+		int jrConditional(int condition) noexcept final;
 
 	private:
 		enum { BC_IDX, DE_IDX, HL_IDX };
@@ -184,136 +184,376 @@ namespace EightBit {
 
 		int8_t m_displacement = 0;
 
-		void handleNMI();
+		void handleNMI() noexcept;
 
-		void resetPrefixes() noexcept;
+		constexpr void resetPrefixes() noexcept {
+			m_prefixCB = m_prefixDD = m_prefixED = m_prefixFD = false;
+		}
 
 		[[nodiscard]] constexpr auto displaced() const noexcept { return m_prefixDD || m_prefixFD; }
-		[[nodiscard]] uint16_t displacedAddress() noexcept;
-		void fetchDisplacement();
-		[[nodiscard]] uint8_t fetchOpCode();
 
-		uint8_t readBusDataM1();
+		[[nodiscard]] constexpr uint16_t displacedAddress() noexcept {
+			const auto address = (m_prefixDD ? IX() : IY()).word + m_displacement;
+			MEMPTR().word = address;
+			return address;
+		}
+
+		void fetchDisplacement() noexcept;
+		[[nodiscard]] uint8_t fetchOpCode() noexcept;
+
+		uint8_t readBusDataM1() noexcept;
 
 		typedef std::function<register16_t(void)> addresser_t;
-		void loadAccumulatorIndirect(addresser_t addresser);
-		void storeAccumulatorIndirect(addresser_t addresser);
+		void loadAccumulatorIndirect(addresser_t addresser) noexcept;
+		void storeAccumulatorIndirect(addresser_t addresser) noexcept;
 
 		typedef std::function<uint8_t(void)> reader_t;
-		void readInternalRegister(reader_t reader);
+		void readInternalRegister(reader_t reader) noexcept;
 
 		[[nodiscard]] register16_t& HL2() noexcept;
 		[[nodiscard]] register16_t& RP(int rp) noexcept;
 		[[nodiscard]] register16_t& RP2(int rp) noexcept;
 
-		[[nodiscard]] uint8_t R(int r);
-		void R(int r, uint8_t value);
-		void R2(int r, uint8_t value);
+		[[nodiscard]] uint8_t R(int r) noexcept;
+		void R(int r, uint8_t value) noexcept;
+		void R2(int r, uint8_t value) noexcept;
 
-		[[nodiscard]] static uint8_t adjustHalfCarryAdd(uint8_t f, uint8_t before, uint8_t value, int calculation) noexcept;
-		[[nodiscard]] static uint8_t adjustHalfCarrySub(uint8_t f, uint8_t before, uint8_t value, int calculation) noexcept;
-		[[nodiscard]] static uint8_t adjustOverflowAdd(uint8_t f, uint8_t before, uint8_t value, uint8_t calculation) noexcept;
-		[[nodiscard]] static uint8_t adjustOverflowAdd(uint8_t f, int beforeNegative, int valueNegative, int afterNegative) noexcept;
-		[[nodiscard]] static uint8_t adjustOverflowSub(uint8_t f, uint8_t before, uint8_t value, uint8_t calculation) noexcept;
-		[[nodiscard]] static uint8_t adjustOverflowSub(uint8_t f, int beforeNegative, int valueNegative, int afterNegative) noexcept;
+		[[nodiscard]] static constexpr auto adjustHalfCarryAdd(uint8_t f, uint8_t before, uint8_t value, int calculation) noexcept {
+			return setBit(f, HC, calculateHalfCarryAdd(before, value, calculation));
+		}
 
-		[[nodiscard]] static bool convertCondition(uint8_t f, int flag) noexcept;
+		[[nodiscard]] static constexpr auto adjustHalfCarrySub(uint8_t f, uint8_t before, uint8_t value, int calculation) noexcept {
+			return setBit(f, HC, calculateHalfCarrySub(before, value, calculation));
+		}
 
-		static uint8_t subtract(uint8_t& f, uint8_t operand, uint8_t value, int carry = 0) noexcept;
+		[[nodiscard]] static constexpr auto adjustOverflowAdd(uint8_t f, int beforeNegative, int valueNegative, int afterNegative) noexcept {
+			const auto overflow = (beforeNegative == valueNegative) && (beforeNegative != afterNegative);
+			return setBit(f, VF, overflow);
+		}
 
-		void executeCB(int x, int y, int z);
-		void executeED(int x, int y, int z, int p, int q);
-		void executeOther(int x, int y, int z, int p, int q);
+		[[nodiscard]] static constexpr auto adjustOverflowAdd(uint8_t f, uint8_t before, uint8_t value, uint8_t calculation) noexcept {
+			return adjustOverflowAdd(f, before & SF, value & SF, calculation & SF);
+		}
 
-		[[nodiscard]] static uint8_t increment(uint8_t& f, uint8_t operand) noexcept;
-		[[nodiscard]] static uint8_t decrement(uint8_t& f, uint8_t operand) noexcept;
+		[[nodiscard]] static constexpr auto adjustOverflowSub(uint8_t f, int beforeNegative, int valueNegative, int afterNegative) noexcept {
+			const auto overflow = (beforeNegative != valueNegative) && (beforeNegative != afterNegative);
+			return setBit(f, VF, overflow);
+		}
+
+		[[nodiscard]] static constexpr auto adjustOverflowSub(uint8_t f, uint8_t before, uint8_t value, uint8_t calculation) noexcept {
+			return adjustOverflowSub(f, before & SF, value & SF, calculation & SF);
+		}
+
+		[[nodiscard]] static constexpr bool convertCondition(uint8_t f, int flag) noexcept {
+			switch (flag) {
+			case 0:
+				return !(f & ZF);
+			case 1:
+				return f & ZF;
+			case 2:
+				return !(f & CF);
+			case 3:
+				return f & CF;
+			case 4:
+				return !(f & PF);
+			case 5:
+				return f & PF;
+			case 6:
+				return !(f & SF);
+			case 7:
+				return f & SF;
+			default:
+				UNREACHABLE;
+			}
+		}
+
+		static constexpr auto subtract(uint8_t& f, uint8_t operand, uint8_t value, int carry = 0) noexcept {
+			const register16_t subtraction = operand - value - carry;
+			const auto result = subtraction.low;
+
+			f = adjustHalfCarrySub(f, operand, value, result);
+			f = adjustOverflowSub(f, operand, value, result);
+
+			f = setBit(f, NF);
+			f = setBit(f, CF, subtraction.high & CF);
+			f = adjustSZ<Z80>(f, result);
+
+			return result;
+		}
+
+		void executeCB(int x, int y, int z) noexcept;
+		void executeED(int x, int y, int z, int p, int q) noexcept;
+		void executeOther(int x, int y, int z, int p, int q) noexcept;
+
+		[[nodiscard]] static constexpr auto increment(uint8_t& f, uint8_t operand) noexcept {
+			f = clearBit(f, NF);
+			const uint8_t result = operand + 1;
+			f = adjustSZXY<Z80>(f, result);
+			f = setBit(f, VF, result == Bit7);
+			f = clearBit(f, HC, lowNibble(result));
+			return result;
+		}
+
+		[[nodiscard]] static constexpr auto decrement(uint8_t& f, uint8_t operand) noexcept {
+			f = setBit(f, NF);
+			f = clearBit(f, HC, lowNibble(operand));
+			const uint8_t result = operand - 1;
+			f = adjustSZXY<Z80>(f, result);
+			f = setBit(f, VF, result == Mask7);
+			return result;
+		}
 
 		void di() noexcept;
 		void ei() noexcept;
 
-		void retn();
-		void reti();
+		void retn() noexcept;
+		void reti() noexcept;
 
-		void returnConditionalFlag(uint8_t f, int flag);
-		void jrConditionalFlag(uint8_t f, int flag);
-		void callConditionalFlag(uint8_t f, int flag);
-		void jumpConditionalFlag(uint8_t f, int flag);
+		void returnConditionalFlag(uint8_t f, int flag) noexcept;
+		void jrConditionalFlag(uint8_t f, int flag) noexcept;
+		void callConditionalFlag(uint8_t f, int flag) noexcept;
+		void jumpConditionalFlag(uint8_t f, int flag) noexcept;
 
-		[[nodiscard]] register16_t sbc(uint8_t& f, register16_t operand, register16_t value);
-		[[nodiscard]] register16_t adc(uint8_t& f, register16_t operand, register16_t value);
-		[[nodiscard]] register16_t add(uint8_t& f, register16_t operand, register16_t value, int carry = 0);
+		[[nodiscard]] register16_t sbc(uint8_t& f, register16_t operand, register16_t value) noexcept;
+		[[nodiscard]] register16_t adc(uint8_t& f, register16_t operand, register16_t value) noexcept;
+		[[nodiscard]] register16_t add(uint8_t& f, register16_t operand, register16_t value, int carry = 0) noexcept;
 
-		[[nodiscard]] static uint8_t add(uint8_t& f, uint8_t operand, uint8_t value, int carry = 0) noexcept;
-		[[nodiscard]] static uint8_t adc(uint8_t& f, uint8_t operand, uint8_t value) noexcept;
-		[[nodiscard]] static uint8_t sub(uint8_t& f, uint8_t operand, uint8_t value, int carry = 0) noexcept;
-		[[nodiscard]] static uint8_t sbc(uint8_t& f, uint8_t operand, uint8_t value) noexcept;
-		[[nodiscard]] static uint8_t andr(uint8_t& f, uint8_t operand, uint8_t value) noexcept;
-		[[nodiscard]] static uint8_t xorr(uint8_t& f, uint8_t operand, uint8_t value) noexcept;
-		[[nodiscard]] static uint8_t orr(uint8_t& f, uint8_t operand, uint8_t value) noexcept;
-		static void compare(uint8_t& f, uint8_t operand, uint8_t value) noexcept;
+		[[nodiscard]] static constexpr auto add(uint8_t& f, uint8_t operand, uint8_t value, int carry = 0) noexcept {
+			const register16_t addition = operand + value + carry;
+			const auto result = addition.low;
 
-		[[nodiscard]] static uint8_t rlc(uint8_t& f, uint8_t operand) noexcept;
-		[[nodiscard]] static uint8_t rrc(uint8_t& f, uint8_t operand) noexcept;
-		[[nodiscard]] static uint8_t rl(uint8_t& f, uint8_t operand) noexcept;
-		[[nodiscard]] static uint8_t rr(uint8_t& f, uint8_t operand) noexcept;
-		[[nodiscard]] static uint8_t sla(uint8_t& f, uint8_t operand) noexcept;
-		[[nodiscard]] static uint8_t sra(uint8_t& f, uint8_t operand) noexcept;
-		[[nodiscard]] static uint8_t sll(uint8_t& f, uint8_t operand) noexcept;
-		[[nodiscard]] static uint8_t srl(uint8_t& f, uint8_t operand) noexcept;
+			f = adjustHalfCarryAdd(f, operand, value, result);
+			f = adjustOverflowAdd(f, operand, value, result);
 
-		static void bit(uint8_t& f, int n, uint8_t operand) noexcept;
-		[[nodiscard]] static uint8_t res(int n, uint8_t operand) noexcept;
-		[[nodiscard]] static uint8_t set(int n, uint8_t operand) noexcept;
+			f = clearBit(f, NF);
+			f = setBit(f, CF, addition.high & CF);
+			f = adjustSZXY<Z80>(f, result);
 
-		[[nodiscard]] static uint8_t daa(uint8_t& f, uint8_t operand) noexcept;
+			return result;
+		}
 
-		static void scf(uint8_t& f, uint8_t operand) noexcept;
-		static void ccf(uint8_t& f, uint8_t operand) noexcept;
-		[[nodiscard]] static uint8_t cpl(uint8_t& f, uint8_t operand) noexcept;
+		[[nodiscard]] static constexpr auto adc(uint8_t& f, uint8_t operand, uint8_t value) noexcept {
+			return add(f, operand, value, f & CF);
+		}
 
-		void xhtl(register16_t& exchange);
+		[[nodiscard]] static constexpr auto sub(uint8_t& f, uint8_t operand, uint8_t value, int carry = 0) noexcept {
+			const auto subtraction = subtract(f, operand, value, carry);
+			f = adjustSZXY<Z80>(f, subtraction);
+			return subtraction;
+		}
 
-		void blockCompare(uint8_t& f, uint8_t value, register16_t source, register16_t& counter);
+		[[nodiscard]] static constexpr auto sbc(uint8_t& f, uint8_t operand, uint8_t value) noexcept {
+			return sub(f, operand, value, f & CF);
+		}
 
-		void cpi(uint8_t& f, uint8_t value);
-		[[nodiscard]] bool cpir(uint8_t& f, uint8_t value);
+		[[nodiscard]] static constexpr auto andr(uint8_t& f, uint8_t operand, uint8_t value) noexcept {
+			f = setBit(f, HC);
+			f = clearBit(f, CF | NF);
+			const uint8_t result = operand & value;
+			f = adjustSZPXY<Z80>(f, result);
+			return result;
+		}
 
-		void cpd(uint8_t& f, uint8_t value);
-		[[nodiscard]] bool cpdr(uint8_t& f, uint8_t value);
+		[[nodiscard]] static constexpr auto xorr(uint8_t& f, uint8_t operand, uint8_t value) noexcept {
+			f = clearBit(f, HC | CF | NF);
+			const uint8_t result = operand ^ value;
+			f = adjustSZPXY<Z80>(f, result);
+			return result;
+		}
 
-		void blockLoad(uint8_t& f, uint8_t a, register16_t source, register16_t destination, register16_t& counter);
+		[[nodiscard]] static constexpr auto orr(uint8_t& f, uint8_t operand, uint8_t value) noexcept {
+			f = clearBit(f, HC | CF | NF);
+			const uint8_t result = operand | value;
+			f = adjustSZPXY<Z80>(f, result);
+			return result;
+		}
 
-		void ldi(uint8_t& f, uint8_t a);
-		[[nodiscard]] bool ldir(uint8_t& f, uint8_t a);
+		static void compare(uint8_t& f, uint8_t operand, uint8_t value) noexcept {
+			subtract(f, operand, value);
+			f = adjustXY<Z80>(f, value);
+		}
 
-		void ldd(uint8_t& f, uint8_t a);
-		[[nodiscard]] bool lddr(uint8_t& f, uint8_t a);
+		[[nodiscard]] static constexpr auto rlc(uint8_t& f, uint8_t operand) noexcept {
+			f = clearBit(f, NF | HC);
+			const auto carry = operand & Bit7;
+			f = setBit(f, CF, carry);
+			const uint8_t result = (operand << 1) | (carry >> 7);
+			f = adjustXY<Z80>(f, result);
+			return result;
+		}
 
-		void blockIn(register16_t& source, register16_t destination);
+		[[nodiscard]] static constexpr auto rrc(uint8_t& f, uint8_t operand) noexcept {
+			f = clearBit(f, NF | HC);
+			const auto carry = operand & Bit0;
+			f = setBit(f, CF, carry);
+			const uint8_t result = (operand >> 1) | (carry << 7);
+			f = adjustXY<Z80>(f, result);
+			return result;
+		}
 
-		void ini();
-		[[nodiscard]] bool inir();
+		[[nodiscard]] static constexpr auto rl(uint8_t& f, uint8_t operand) noexcept {
+			f = clearBit(f, NF | HC);
+			const auto carry = f & CF;
+			f = setBit(f, CF, operand & Bit7);
+			const uint8_t result = (operand << 1) | carry;
+			f = adjustXY<Z80>(f, result);
+			return result;
+		}
 
-		void ind();
-		[[nodiscard]] bool indr();
+		[[nodiscard]] static constexpr auto rr(uint8_t& f, uint8_t operand) noexcept {
+			f = clearBit(f, NF | HC);
+			const auto carry = f & CF;
+			f = setBit(f, CF, operand & Bit0);
+			const uint8_t result = (operand >> 1) | (carry << 7);
+			f = adjustXY<Z80>(f, result);
+			return result;
+		}
 
-		void blockOut(register16_t source, register16_t& destination);
+		[[nodiscard]] static constexpr auto sla(uint8_t& f, uint8_t operand) noexcept {
+			f = clearBit(f, NF | HC);
+			f = setBit(f, CF, operand & Bit7);
+			const uint8_t result = operand << 1;
+			f = adjustXY<Z80>(f, result);
+			return result;
+		}
 
-		void outi();
-		[[nodiscard]] bool otir();
+		[[nodiscard]] static constexpr auto sra(uint8_t& f, uint8_t operand) noexcept {
+			f = clearBit(f, NF | HC);
+			f = setBit(f, CF, operand & Bit0);
+			const uint8_t result = (operand >> 1) | (operand & Bit7);
+			f = adjustXY<Z80>(f, result);
+			return result;
+		}
 
-		void outd();
-		[[nodiscard]] bool otdr();
+		[[nodiscard]] static constexpr auto sll(uint8_t& f, uint8_t operand) noexcept {
+			f = clearBit(f, NF | HC);
+			f = setBit(f, CF, operand & Bit7);
+			const uint8_t result = (operand << 1) | Bit0;
+			f = adjustXY<Z80>(f, result);
+			return result;
+		}
 
-		[[nodiscard]] uint8_t neg(uint8_t& f, uint8_t operand) noexcept;
+		[[nodiscard]] static constexpr auto srl(uint8_t& f, uint8_t operand) noexcept {
+			f = clearBit(f, NF | HC);
+			f = setBit(f, CF, operand & Bit0);
+			const uint8_t result = (operand >> 1) & ~Bit7;
+			f = adjustXY<Z80>(f, result);
+			f = setBit(f, ZF, result);
+			return result;
+		}
 
-		void rrd(uint8_t& f, register16_t address, uint8_t& update);
-		void rld(uint8_t& f, register16_t address, uint8_t& update);
+		static constexpr void bit(uint8_t& f, int n, uint8_t operand) noexcept {
+			f = setBit(f, HC);
+			f = clearBit(f, NF);
+			const auto discarded = operand & Chip::bit(n);
+			f = adjustSZ<Z80>(f, discarded);
+			f = clearBit(f, PF, discarded);
+		}
 
-		void portWrite(uint8_t port);
-		void portWrite();
+		[[nodiscard]] static constexpr auto res(int n, uint8_t operand) noexcept { return clearBit(operand, Chip::bit(n)); }
+		[[nodiscard]] static constexpr auto set(int n, uint8_t operand) noexcept { return setBit(operand, Chip::bit(n)); }
 
-		uint8_t portRead(uint8_t port);
-		uint8_t portRead();
+		[[nodiscard]] static constexpr auto daa(uint8_t& f, uint8_t operand) noexcept {
+			const auto lowAdjust = (f & HC) || (lowNibble(operand) > 9);
+			const auto highAdjust = (f & CF) || (operand > 0x99);
+
+			auto updated = operand;
+			if (f & NF) {
+				if (lowAdjust)
+					updated -= 6;
+				if (highAdjust)
+					updated -= 0x60;
+			} else {
+				if (lowAdjust)
+					updated += 6;
+				if (highAdjust)
+					updated += 0x60;
+			}
+
+			f = (f & (CF | NF)) | (operand > 0x99 ? CF : 0) | ((operand ^ updated) & HC);
+
+			f = adjustSZPXY<Z80>(f, updated);
+
+			return updated;
+		}
+
+		static constexpr void scf(uint8_t& f, uint8_t operand) noexcept {
+			f = setBit(f, CF);
+			f = clearBit(f, HC | NF);
+			f = adjustXY<Z80>(f, operand);
+		}
+
+		static constexpr void ccf(uint8_t& f, uint8_t operand) noexcept {
+			f = clearBit(f, NF);
+			const auto carry = f & CF;
+			f = setBit(f, HC, carry);
+			f = clearBit(f, CF, carry);
+			f = adjustXY<Z80>(f, operand);
+		}
+
+		[[nodiscard]] static constexpr auto cpl(uint8_t& f, uint8_t operand) noexcept {
+			f = setBit(f, HC | NF);
+			const uint8_t result = ~operand;
+			f = adjustXY<Z80>(f, result);
+			return result;
+		}
+
+		void xhtl(register16_t& exchange) noexcept;
+
+		void blockCompare(uint8_t& f, uint8_t value, register16_t source, register16_t& counter) noexcept;
+
+		void cpi(uint8_t& f, uint8_t value) noexcept;
+		[[nodiscard]] bool cpir(uint8_t& f, uint8_t value) noexcept;
+
+		void cpd(uint8_t& f, uint8_t value) noexcept;
+		[[nodiscard]] bool cpdr(uint8_t& f, uint8_t value) noexcept;
+
+		void blockLoad(uint8_t& f, uint8_t a, register16_t source, register16_t destination, register16_t& counter) noexcept;
+
+		void ldi(uint8_t& f, uint8_t a) noexcept;
+		[[nodiscard]] bool ldir(uint8_t& f, uint8_t a) noexcept;
+
+		void ldd(uint8_t& f, uint8_t a) noexcept;
+		[[nodiscard]] bool lddr(uint8_t& f, uint8_t a) noexcept;
+
+		void blockIn(register16_t& source, register16_t destination) noexcept;
+
+		void ini() noexcept;
+		[[nodiscard]] bool inir() noexcept;
+
+		void ind() noexcept;
+		[[nodiscard]] bool indr() noexcept;
+
+		void blockOut(register16_t source, register16_t& destination) noexcept;
+
+		void outi() noexcept;
+		[[nodiscard]] bool otir() noexcept;
+
+		void outd() noexcept;
+		[[nodiscard]] bool otdr() noexcept;
+
+		[[nodiscard]] static constexpr auto neg(uint8_t& f, uint8_t operand) noexcept {
+			f = setBit(f, PF, operand == Bit7);
+			f = setBit(f, CF, operand);
+			f = setBit(f, NF);
+
+			const uint8_t result = (~operand + 1);	// two's complement
+
+			f = adjustHalfCarrySub(f, 0U, operand, result);
+			f = adjustOverflowSub(f, 0U, operand, result);
+
+			f = adjustSZXY<Z80>(f, result);
+
+			return result;
+		}
+
+		void rrd(uint8_t& f, register16_t address, uint8_t& update) noexcept;
+		void rld(uint8_t& f, register16_t address, uint8_t& update) noexcept;
+
+		void portWrite(uint8_t port) noexcept;
+		void portWrite() noexcept;
+
+		uint8_t portRead(uint8_t port) noexcept;
+		uint8_t portRead() noexcept;
 	};
 }
\ No newline at end of file
diff --git a/Z80/src/Z80.cpp b/Z80/src/Z80.cpp
index 21e7137..7fa2189 100644
--- a/Z80/src/Z80.cpp
+++ b/Z80/src/Z80.cpp
@@ -46,8 +46,6 @@ EightBit::Z80::Z80(const Z80& rhs)
 	m_ix = rhs.m_ix;
 	m_iy = rhs.m_iy;
 
-	m_refresh = rhs.m_refresh;
-
 	iv = rhs.iv;
 	m_interruptMode = rhs.m_interruptMode;
 	m_iff1 = rhs.m_iff1;
@@ -131,23 +129,24 @@ const EightBit::register16_t& EightBit::Z80::HL() const noexcept {
 	return m_registers[m_registerSet][HL_IDX];
 }
 
-void EightBit::Z80::pushWord(const register16_t destination) {
+void EightBit::Z80::pushWord(const register16_t destination) noexcept {
 	tick();
 	IntelProcessor::pushWord(destination);
 }
 
-void EightBit::Z80::memoryWrite() {
+void EightBit::Z80::memoryWrite() noexcept {
 
 	class _Writer final {
 		Z80& m_parent;
 	public:
-		_Writer(Z80& parent) : m_parent(parent) {
+		_Writer(Z80& parent) noexcept
+		: m_parent(parent) {
 			m_parent.WritingMemory.fire();
 			m_parent.tick(2);
 			m_parent.lowerMREQ();
 		}
 
-		~_Writer() {
+		~_Writer() noexcept {
 			m_parent.raiseMREQ();
 			m_parent.WrittenMemory.fire();
 		}
@@ -157,12 +156,13 @@ void EightBit::Z80::memoryWrite() {
 	IntelProcessor::memoryWrite();
 }
 
-uint8_t EightBit::Z80::memoryRead() {
+uint8_t EightBit::Z80::memoryRead() noexcept {
 
 	class _Reader final {
 		Z80& m_parent;
 	public:
-		_Reader(Z80& parent) : m_parent(parent) {
+		_Reader(Z80& parent) noexcept
+		: m_parent(parent) {
 			m_parent.ReadingMemory.fire();
 			if (lowered(m_parent.M1()))
 				m_parent.tick();
@@ -170,7 +170,7 @@ uint8_t EightBit::Z80::memoryRead() {
 			m_parent.lowerMREQ();
 		}
 
-		~_Reader() {
+		~_Reader() noexcept {
 			m_parent.raiseMREQ();
 			m_parent.ReadMemory.fire();
 		}
@@ -180,27 +180,28 @@ uint8_t EightBit::Z80::memoryRead() {
 	return IntelProcessor::memoryRead();
 }
 
-void EightBit::Z80::busWrite() {
+void EightBit::Z80::busWrite() noexcept {
 	tick();
 	_ActivateWR writer(*this);
 	IntelProcessor::busWrite();
 }
 
-uint8_t EightBit::Z80::busRead() {
+uint8_t EightBit::Z80::busRead() noexcept {
 	tick();
 	_ActivateRD reader(*this);
 	return IntelProcessor::busRead();
 }
 
-void EightBit::Z80::handleRESET() {
+void EightBit::Z80::handleRESET() noexcept {
 	IntelProcessor::handleRESET();
 	di();
-	IV() = REFRESH() = 0;
+	IV() = 0;
+	REFRESH() = 0;
 	SP().word = AF().word = Mask16;
 	tick(3);
 }
 
-void EightBit::Z80::handleNMI() {
+void EightBit::Z80::handleNMI() noexcept {
 	raiseNMI();
 	raiseHALT();
 	IFF2() = IFF1();
@@ -209,7 +210,7 @@ void EightBit::Z80::handleNMI() {
 	restart(0x66);
 }
 
-void EightBit::Z80::handleINT() {
+void EightBit::Z80::handleINT() noexcept {
 	IntelProcessor::handleINT();
 	tick(2);	// 2 extra clock cycles introduced to allow the bus to settle
 	uint8_t data;
@@ -242,112 +243,45 @@ void EightBit::Z80::ei() noexcept {
 	IFF1() = IFF2() = true;
 }
 
-uint8_t EightBit::Z80::increment(uint8_t& f, const uint8_t operand) noexcept {
-	f = clearBit(f, NF);
-	const uint8_t result = operand + 1;
-	f = adjustSZXY<Z80>(f, result);
-	f = setBit(f, VF, result == Bit7);
-	f = clearBit(f, HC, lowNibble(result));
-	return result;
-}
-
-uint8_t EightBit::Z80::decrement(uint8_t& f, const uint8_t operand) noexcept {
-	f = setBit(f, NF);
-	f = clearBit(f, HC, lowNibble(operand));
-	const uint8_t result = operand - 1;
-	f = adjustSZXY<Z80>(f, result);
-	f = setBit(f, VF, result == Mask7);
-	return result;
-}
-
-uint8_t EightBit::Z80::adjustHalfCarryAdd(const uint8_t f, const uint8_t before, const uint8_t value, const int calculation) noexcept {
-	return setBit(f, HC, calculateHalfCarryAdd(before, value, calculation));
-}
-
-uint8_t EightBit::Z80::adjustHalfCarrySub(const uint8_t f, const uint8_t before, const uint8_t value, const int calculation) noexcept {
-	return setBit(f, HC, calculateHalfCarrySub(before, value, calculation));
-}
-
-uint8_t EightBit::Z80::adjustOverflowAdd(const uint8_t f, const uint8_t before, const uint8_t value, const uint8_t calculation) noexcept {
-	return adjustOverflowAdd(f, before & SF, value & SF, calculation & SF);
-}
-
-uint8_t EightBit::Z80::adjustOverflowAdd(const uint8_t f, const int beforeNegative, const int valueNegative, const int afterNegative) noexcept {
-	const auto overflow = (beforeNegative == valueNegative) && (beforeNegative != afterNegative);
-	return setBit(f, VF, overflow);
-}
-
-uint8_t EightBit::Z80::adjustOverflowSub(const uint8_t f, const uint8_t before, const uint8_t value, const uint8_t calculation) noexcept {
-	return adjustOverflowSub(f, before & SF, value & SF, calculation & SF);
-}
-
-uint8_t EightBit::Z80::adjustOverflowSub(const uint8_t f, const int beforeNegative, const int valueNegative, const int afterNegative) noexcept {
-	const auto overflow = (beforeNegative != valueNegative) && (beforeNegative != afterNegative);
-	return setBit(f, VF, overflow);
-}
-
-bool EightBit::Z80::convertCondition(const uint8_t f, int flag) noexcept {
-	switch (flag) {
-	case 0:
-		return !(f & ZF);
-	case 1:
-		return f & ZF;
-	case 2:
-		return !(f & CF);
-	case 3:
-		return f & CF;
-	case 4:
-		return !(f & PF);
-	case 5:
-		return f & PF;
-	case 6:
-		return !(f & SF);
-	case 7:
-		return f & SF;
-	default:
-		UNREACHABLE;
-	}
-}
-
-void EightBit::Z80::returnConditionalFlag(const uint8_t f, const int flag) {
+void EightBit::Z80::returnConditionalFlag(const uint8_t f, const int flag) noexcept {
 	tick();
 	if (convertCondition(f, flag))
 		ret();
 }
 
-void EightBit::Z80::jrConditionalFlag(const uint8_t f, const int flag) {
+void EightBit::Z80::jrConditionalFlag(const uint8_t f, const int flag) noexcept {
 	jrConditional(convertCondition(f, flag));
 }
 
-void EightBit::Z80::jumpConditionalFlag(const uint8_t f, const int flag) {
+void EightBit::Z80::jumpConditionalFlag(const uint8_t f, const int flag) noexcept {
 	jumpConditional(convertCondition(f, flag));
 }
 
-void EightBit::Z80::callConditionalFlag(const uint8_t f, const int flag) {
+void EightBit::Z80::callConditionalFlag(const uint8_t f, const int flag) noexcept {
 	callConditional(convertCondition(f, flag));
 }
 
-void EightBit::Z80::retn() {
+void EightBit::Z80::retn() noexcept {
 	ret();
 	IFF1() = IFF2();
 }
 
-void EightBit::Z80::reti() {
+void EightBit::Z80::reti() noexcept {
 	retn();
 }
 
-void EightBit::Z80::jr(int8_t offset) {
+void EightBit::Z80::jr(int8_t offset) noexcept {
 	IntelProcessor::jr(offset);
 	tick(5);
 }
 
-int EightBit::Z80::jrConditional(const int condition) {
+int EightBit::Z80::jrConditional(const int condition) noexcept {
 	if (!IntelProcessor::jrConditional(condition))
 		tick(3);
 	return condition;
 }
 
-EightBit::register16_t EightBit::Z80::sbc(uint8_t& f, const register16_t operand, const register16_t value) {
+EightBit::register16_t EightBit::Z80::sbc(uint8_t& f, const register16_t operand, const register16_t value) noexcept {
 
 	const auto subtraction = operand.word - value.word - (f & CF);
 	const register16_t result = subtraction;
@@ -371,7 +305,7 @@ EightBit::register16_t EightBit::Z80::sbc(uint8_t& f, const register16_t operand
 	return result;
 }
 
-EightBit::register16_t EightBit::Z80::adc(uint8_t& f, const register16_t operand, const register16_t value) {
+EightBit::register16_t EightBit::Z80::adc(uint8_t& f, const register16_t operand, const register16_t value) noexcept {
 
 	const auto result = add(f, operand, value, f & CF);
 	f = clearBit(f, ZF, result.word);
@@ -386,7 +320,7 @@ EightBit::register16_t EightBit::Z80::adc(uint8_t& f, const register16_t operand
 	return result;
 }
 
-EightBit::register16_t EightBit::Z80::add(uint8_t& f, const register16_t operand, const register16_t value, int carry) {
+EightBit::register16_t EightBit::Z80::add(uint8_t& f, const register16_t operand, const register16_t value, int carry) noexcept {
 
 	const int addition = operand.word + value.word + carry;
 	const register16_t result = addition;
@@ -402,227 +336,7 @@ EightBit::register16_t EightBit::Z80::add(uint8_t& f, const register16_t operand
 	return result;
 }
 
-uint8_t EightBit::Z80::add(uint8_t& f, const uint8_t operand, const uint8_t value, const int carry) noexcept {
-
-	const register16_t addition = operand + value + carry;
-	const auto result = addition.low;
-
-	f = adjustHalfCarryAdd(f, operand, value, result);
-	f = adjustOverflowAdd(f, operand, value, result);
-
-	f = clearBit(f, NF);
-	f = setBit(f, CF, addition.high & CF);
-	f = adjustSZXY<Z80>(f, result);
-
-	return result;
-}
-
-uint8_t EightBit::Z80::adc(uint8_t& f, const uint8_t operand, const uint8_t value) noexcept {
-	return add(f, operand, value, f & CF);
-}
-
-uint8_t EightBit::Z80::subtract(uint8_t& f, const uint8_t operand, const uint8_t value, const int carry) noexcept {
-
-	const register16_t subtraction = operand - value - carry;
-	const auto result = subtraction.low;
-
-	f = adjustHalfCarrySub(f, operand, value, result);
-	f = adjustOverflowSub(f, operand, value, result);
-
-	f = setBit(f, NF);
-	f = setBit(f, CF, subtraction.high & CF);
-	f = adjustSZ<Z80>(f, result);
-
-	return result;
-}
-
-uint8_t EightBit::Z80::sub(uint8_t& f, const uint8_t operand, const uint8_t value, const int carry) noexcept {
-	const auto subtraction = subtract(f, operand, value, carry);
-	f = adjustXY<Z80>(f, subtraction);
-	return subtraction;
-}
-
-uint8_t EightBit::Z80::sbc(uint8_t& f, const uint8_t operand, const uint8_t value) noexcept {
-	return sub(f, operand, value, f & CF);
-}
-
-uint8_t EightBit::Z80::andr(uint8_t& f, const uint8_t operand, const uint8_t value) noexcept {
-	f = setBit(f, HC);
-	f = clearBit(f, CF | NF);
-	const uint8_t result = operand & value;
-	f = adjustSZPXY<Z80>(f, result);
-	return result;
-}
-
-uint8_t EightBit::Z80::xorr(uint8_t& f, const uint8_t operand, const uint8_t value) noexcept {
-	f = clearBit(f, HC | CF | NF);
-	const uint8_t result = operand ^ value;
-	f = adjustSZPXY<Z80>(f, result);
-	return result;
-}
-
-uint8_t EightBit::Z80::orr(uint8_t& f, const uint8_t operand, const uint8_t value) noexcept {
-	f = clearBit(f, HC | CF | NF);
-	const uint8_t result = operand | value;
-	f = adjustSZPXY<Z80>(f, result);
-	return result;
-}
-
-void EightBit::Z80::compare(uint8_t& f, uint8_t operand, const uint8_t value) noexcept {
-	subtract(f, operand, value);
-	f = adjustXY<Z80>(f, value);
-}
-
-uint8_t EightBit::Z80::rlc(uint8_t& f, const uint8_t operand) noexcept {
-	f = clearBit(f, NF | HC);
-	const auto carry = operand & Bit7;
-	f = setBit(f, CF, carry);
-	const uint8_t result = (operand << 1) | (carry >> 7);
-	f = adjustXY<Z80>(f, result);
-	return result;
-}
-
-uint8_t EightBit::Z80::rrc(uint8_t& f, const uint8_t operand) noexcept {
-	f = clearBit(f, NF | HC);
-	const auto carry = operand & Bit0;
-	f = setBit(f, CF, carry);
-	const uint8_t result = (operand >> 1) | (carry << 7);
-	f = adjustXY<Z80>(f, result);
-	return result;
-}
-
-uint8_t EightBit::Z80::rl(uint8_t& f, const uint8_t operand) noexcept {
-	f = clearBit(f, NF | HC);
-	const auto carry = f & CF;
-	f = setBit(f, CF, operand & Bit7);
-	const uint8_t result = (operand << 1) | carry;
-	f = adjustXY<Z80>(f, result);
-	return result;
-}
-
-uint8_t EightBit::Z80::rr(uint8_t& f, const uint8_t operand) noexcept {
-	f = clearBit(f, NF | HC);
-	const auto carry = f & CF;
-	f = setBit(f, CF, operand & Bit0);
-	const uint8_t result = (operand >> 1) | (carry << 7);
-	f = adjustXY<Z80>(f, result);
-	return result;
-}
-
-//
-
-uint8_t EightBit::Z80::sla(uint8_t& f, const uint8_t operand) noexcept {
-	f = clearBit(f, NF | HC);
-	f = setBit(f, CF, operand & Bit7);
-	const uint8_t result = operand << 1;
-	f = adjustXY<Z80>(f, result);
-	return result;
-}
-
-uint8_t EightBit::Z80::sra(uint8_t& f, const uint8_t operand) noexcept {
-	f = clearBit(f, NF | HC);
-	f = setBit(f, CF, operand & Bit0);
-	const uint8_t result = (operand >> 1) | (operand & Bit7);
-	f = adjustXY<Z80>(f, result);
-	return result;
-}
-
-uint8_t EightBit::Z80::sll(uint8_t& f, const uint8_t operand) noexcept {
-	f = clearBit(f, NF | HC);
-	f = setBit(f, CF, operand & Bit7);
-	const uint8_t result = (operand << 1) | Bit0;
-	f = adjustXY<Z80>(f, result);
-	return result;
-}
-
-uint8_t EightBit::Z80::srl(uint8_t& f, const uint8_t operand) noexcept {
-	f = clearBit(f, NF | HC);
-	f = setBit(f, CF, operand & Bit0);
-	const uint8_t result = (operand >> 1) & ~Bit7;
-	f = adjustXY<Z80>(f, result);
-	f = setBit(f, ZF, result);
-	return result;
-}
-
-void EightBit::Z80::bit(uint8_t& f, const int n, const uint8_t operand) noexcept {
-	f = setBit(f, HC);
-	f = clearBit(f, NF);
-	const auto discarded = operand & Chip::bit(n);
-	f = adjustSZ<Z80>(f, discarded);
-	f = clearBit(f, PF, discarded);
-}
-
-uint8_t EightBit::Z80::res(const int n, const uint8_t operand) noexcept {
-	return clearBit(operand, Chip::bit(n));
-}
-
-uint8_t EightBit::Z80::set(const int n, const uint8_t operand) noexcept {
-	return setBit(operand, Chip::bit(n));
-}
-
-uint8_t EightBit::Z80::neg(uint8_t& f, uint8_t operand) noexcept {
-
-	f = setBit(f, PF, operand == Bit7);
-	f = setBit(f, CF, operand);
-	f = setBit(f, NF);
-
-	const uint8_t result = (~operand + 1);	// two's complement
-
-	f = adjustHalfCarrySub(f, 0U, operand, result);
-	f = adjustOverflowSub(f, 0U, operand, result);
-
-	f = adjustSZXY<Z80>(f, result);
-
-	return result;
-}
-
-uint8_t EightBit::Z80::daa(uint8_t& f, uint8_t operand) noexcept {
-
-	const auto lowAdjust = (f & HC) || (lowNibble(operand) > 9);
-	const auto highAdjust = (f & CF) || (operand > 0x99);
-
-	auto updated = operand;
-	if (f & NF) {
-		if (lowAdjust)
-			updated -= 6;
-		if (highAdjust)
-			updated -= 0x60;
-	} else {
-		if (lowAdjust)
-			updated += 6;
-		if (highAdjust)
-			updated += 0x60;
-	}
-
-	f = (f & (CF | NF)) | (operand > 0x99 ? CF : 0) | ((operand ^ updated) & HC);
-
-	f = adjustSZPXY<Z80>(f, updated);
-
-	return updated;
-}
-
-uint8_t EightBit::Z80::cpl(uint8_t& f, const uint8_t operand) noexcept {
-	f = setBit(f, HC | NF);
-	const uint8_t result = ~operand;
-	f = adjustXY<Z80>(f, result);
-	return result;
-}
-
-void EightBit::Z80::scf(uint8_t& f, const uint8_t operand) noexcept {
-	f = setBit(f, CF);
-	f = clearBit(f, HC | NF);
-	f = adjustXY<Z80>(f, operand);
-}
-
-void EightBit::Z80::ccf(uint8_t& f, const uint8_t operand) noexcept {
-	f = clearBit(f, NF);
-	const auto carry = f & CF;
-	f = setBit(f, HC, carry);
-	f = clearBit(f, CF, carry);
-	f = adjustXY<Z80>(f, operand);
-}
-
-void EightBit::Z80::xhtl(register16_t& exchange) {
+void EightBit::Z80::xhtl(register16_t& exchange) noexcept {
 	MEMPTR().low = IntelProcessor::memoryRead(SP());
 	++BUS().ADDRESS();
 	MEMPTR().high = memoryRead();
@@ -635,7 +349,7 @@ void EightBit::Z80::xhtl(register16_t& exchange) {
 	tick(2);
 }
 
-void EightBit::Z80::blockCompare(uint8_t& f, const uint8_t value, const register16_t source, register16_t& counter) {
+void EightBit::Z80::blockCompare(uint8_t& f, const uint8_t value, const register16_t source, register16_t& counter) noexcept {
 
 	const auto contents = IntelProcessor::memoryRead(source);
 	uint8_t result = value - contents;
@@ -654,27 +368,27 @@ void EightBit::Z80::blockCompare(uint8_t& f, const uint8_t value, const register
 	tick(5);
 }
 
-void EightBit::Z80::cpi(uint8_t& f, uint8_t value) {
+void EightBit::Z80::cpi(uint8_t& f, uint8_t value) noexcept {
 	blockCompare(f, value, HL()++, BC());
 	++MEMPTR();
 }
 
-void EightBit::Z80::cpd(uint8_t& f, uint8_t value) {
+void EightBit::Z80::cpd(uint8_t& f, uint8_t value) noexcept {
 	blockCompare(f, value, HL()--, BC());
 	--MEMPTR();
 }
 
-bool EightBit::Z80::cpir(uint8_t& f, uint8_t value) {
+bool EightBit::Z80::cpir(uint8_t& f, uint8_t value) noexcept {
 	cpi(f, value);
 	return (f & PF) && !(f & ZF);	// See CPI
 }
 
-bool EightBit::Z80::cpdr(uint8_t& f, uint8_t value) {
+bool EightBit::Z80::cpdr(uint8_t& f, uint8_t value) noexcept {
 	cpd(f, value);
 	return (f & PF) && !(f & ZF);	// See CPD
 }
 
-void EightBit::Z80::blockLoad(uint8_t& f, const uint8_t a, const register16_t source, const register16_t destination, register16_t& counter) {
+void EightBit::Z80::blockLoad(uint8_t& f, const uint8_t a, const register16_t source, const register16_t destination, register16_t& counter) noexcept {
 	const auto value = IntelProcessor::memoryRead(source);
 	IntelProcessor::memoryWrite(destination);
 	const auto xy = a + value;
@@ -685,25 +399,25 @@ void EightBit::Z80::blockLoad(uint8_t& f, const uint8_t a, const register16_t so
 	tick(2);
 }
 
-void EightBit::Z80::ldd(uint8_t& f, const uint8_t a) {
+void EightBit::Z80::ldd(uint8_t& f, const uint8_t a) noexcept {
 	blockLoad(f, a, HL()--, DE()--, BC());
 }
 
-void EightBit::Z80::ldi(uint8_t& f, const uint8_t a) {
+void EightBit::Z80::ldi(uint8_t& f, const uint8_t a) noexcept {
 	blockLoad(f, a, HL()++, DE()++, BC());
 }
 
-bool EightBit::Z80::ldir(uint8_t& f, const uint8_t a) {
+bool EightBit::Z80::ldir(uint8_t& f, const uint8_t a) noexcept {
 	ldi(f, a);
 	return !!(f & PF);		// See LDI
 }
 
-bool EightBit::Z80::lddr(uint8_t& f, const uint8_t a) {
+bool EightBit::Z80::lddr(uint8_t& f, const uint8_t a) noexcept {
 	ldd(f, a);
 	return !!(f & PF);		// See LDD
 }
 
-void EightBit::Z80::blockIn(register16_t& source, const register16_t destination) {
+void EightBit::Z80::blockIn(register16_t& source, const register16_t destination) noexcept {
 	MEMPTR() = BUS().ADDRESS() = source;
 	tick();
 	portRead();
@@ -713,27 +427,27 @@ void EightBit::Z80::blockIn(register16_t& source, const register16_t destination
 	F() = setBit(F(), NF);
 }
 
-void EightBit::Z80::ini() {
+void EightBit::Z80::ini() noexcept {
 	blockIn(BC(), HL()++);
 	++MEMPTR();
 }
 
-void EightBit::Z80::ind() {
+void EightBit::Z80::ind() noexcept {
 	blockIn(BC(), HL()--);
 	--MEMPTR();
 }
 
-bool EightBit::Z80::inir() {
+bool EightBit::Z80::inir() noexcept {
 	ini();
 	return !(F() & ZF);	// See INI
 }
 
-bool EightBit::Z80::indr() {
+bool EightBit::Z80::indr() noexcept {
 	ind();
 	return !(F() & ZF);	// See IND
 }
 
-void EightBit::Z80::blockOut(const register16_t source, register16_t& destination) {
+void EightBit::Z80::blockOut(const register16_t source, register16_t& destination) noexcept {
 	tick();
 	const auto value = IntelProcessor::memoryRead(source);
 	destination.high = decrement(F(), destination.high);
@@ -745,27 +459,27 @@ void EightBit::Z80::blockOut(const register16_t source, register16_t& destinatio
 	F() = adjustParity<Z80>(F(), ((value + L()) & Mask3) ^ B());
 }
 
-void EightBit::Z80::outi() {
+void EightBit::Z80::outi() noexcept {
 	blockOut(HL()++, BC());
 	++MEMPTR();
 }
 
-void EightBit::Z80::outd() {
+void EightBit::Z80::outd() noexcept {
 	blockOut(HL()--, BC());
 	--MEMPTR();
 }
 
-bool EightBit::Z80::otir() {
+bool EightBit::Z80::otir() noexcept {
 	outi();
 	return !(F() & ZF);	// See OUTI
 }
 
-bool EightBit::Z80::otdr() {
+bool EightBit::Z80::otdr() noexcept {
 	outd();
 	return !(F() & ZF);	// See OUTD
 }
 
-void EightBit::Z80::rrd(uint8_t& f, register16_t address, uint8_t& update) {
+void EightBit::Z80::rrd(uint8_t& f, register16_t address, uint8_t& update) noexcept {
 	(MEMPTR() = BUS().ADDRESS() = address)++;
 	const auto memory = memoryRead();
 	tick(4);
@@ -775,7 +489,7 @@ void EightBit::Z80::rrd(uint8_t& f, register16_t address, uint8_t& update) {
 	f = clearBit(f, NF | HC);
 }
 
-void EightBit::Z80::rld(uint8_t& f, register16_t address, uint8_t& update) {
+void EightBit::Z80::rld(uint8_t& f, register16_t address, uint8_t& update) noexcept {
 	(MEMPTR() = BUS().ADDRESS() = address)++;
 	const auto memory = memoryRead();
 	tick(4);
@@ -785,23 +499,24 @@ void EightBit::Z80::rld(uint8_t& f, register16_t address, uint8_t& update) {
 	f = clearBit(f, NF | HC);
 }
 
-void EightBit::Z80::portWrite(const uint8_t port) {
+void EightBit::Z80::portWrite(const uint8_t port) noexcept {
 	MEMPTR() = BUS().ADDRESS() = { port, A() };
 	BUS().DATA() = A();
 	portWrite();
 	++MEMPTR().low;
 }
 
-void EightBit::Z80::portWrite() {
+void EightBit::Z80::portWrite() noexcept {
 
 	class _Writer final {
 		Z80& m_parent;
 	public:
-		_Writer(Z80& parent) : m_parent(parent) {
+		_Writer(Z80& parent) noexcept
+		: m_parent(parent) {
 			m_parent.WritingIO.fire();
 		}
 
-		~_Writer() {
+		~_Writer() noexcept {
 			m_parent.WrittenIO.fire();
 			m_parent.tick(3);
 		}
@@ -812,22 +527,23 @@ void EightBit::Z80::portWrite() {
 	busWrite();
 }
 
-uint8_t EightBit::Z80::portRead(const uint8_t port) {
+uint8_t EightBit::Z80::portRead(const uint8_t port) noexcept {
 	MEMPTR() = BUS().ADDRESS() = { port, A() };
 	++MEMPTR().low;
 	return portRead();
 }
 
-uint8_t EightBit::Z80::portRead() {
+uint8_t EightBit::Z80::portRead() noexcept {
 
 	class _Reader final {
 		Z80& m_parent;
 	public:
-		_Reader(Z80& parent) : m_parent(parent) {
+		_Reader(Z80& parent) noexcept
+		: m_parent(parent) {
 			m_parent.ReadingIO.fire();
 		}
 
-		~_Reader() {
+		~_Reader() noexcept {
 			m_parent.ReadIO.fire();
 			m_parent.tick(3);
 		}
@@ -840,23 +556,13 @@ uint8_t EightBit::Z80::portRead() {
 
 //
 
-void EightBit::Z80::resetPrefixes() noexcept {
-	m_prefixCB = m_prefixDD = m_prefixED = m_prefixFD = false;
-}
-
-//
-
-uint16_t EightBit::Z80::displacedAddress() noexcept {
-	return MEMPTR().word = (m_prefixDD ? IX() : IY()).word + m_displacement;
-}
-
-void EightBit::Z80::fetchDisplacement() {
+void EightBit::Z80::fetchDisplacement() noexcept {
 	m_displacement = fetchByte();
 }
 
 //
 
-uint8_t EightBit::Z80::readBusDataM1() {
+uint8_t EightBit::Z80::readBusDataM1() noexcept {
 	_ActivateM1 m1(*this);
 	return BUS().DATA();
 }
@@ -888,7 +594,7 @@ uint8_t EightBit::Z80::readBusDataM1() {
 // received from the memory is ignored and an NOP instruction is forced internally to the
 // CPU.The HALT acknowledge signal is active during this time indicating that the processor
 // is in the HALT state
-uint8_t EightBit::Z80::fetchOpCode() {
+uint8_t EightBit::Z80::fetchOpCode() noexcept {
 	uint8_t returned;
 	{
 		_ActivateM1 m1(*this);
@@ -907,18 +613,18 @@ uint8_t EightBit::Z80::fetchOpCode() {
 	return returned;
 }
 
-void EightBit::Z80::loadAccumulatorIndirect(addresser_t addresser) {
+void EightBit::Z80::loadAccumulatorIndirect(addresser_t addresser) noexcept {
 	(MEMPTR() = BUS().ADDRESS() = addresser())++;
 	A() = memoryRead();
 }
 
-void EightBit::Z80::storeAccumulatorIndirect(addresser_t addresser) {
+void EightBit::Z80::storeAccumulatorIndirect(addresser_t addresser) noexcept {
 	(MEMPTR() = BUS().ADDRESS() = addresser())++;
 	MEMPTR().high = BUS().DATA() = A();
 	memoryWrite();
 }
 
-void EightBit::Z80::readInternalRegister(reader_t reader) {
+void EightBit::Z80::readInternalRegister(reader_t reader) noexcept {
 	F() = adjustSZXY<Z80>(F(), A() = reader());
 	F() = clearBit(F(), NF | HC);
 	F() = setBit(F(), PF, IFF2());
@@ -963,7 +669,7 @@ EightBit::register16_t& EightBit::Z80::RP2(const int rp) noexcept {
 	}
 }
 
-uint8_t EightBit::Z80::R(const int r) {
+uint8_t EightBit::Z80::R(const int r) noexcept {
 	switch (r) {
 	case 0:
 		return B();
@@ -986,7 +692,7 @@ uint8_t EightBit::Z80::R(const int r) {
 	}
 }
 
-void EightBit::Z80::R(const int r, const uint8_t value) {
+void EightBit::Z80::R(const int r, const uint8_t value) noexcept {
 	switch (r) {
 	case 0:
 		B() = value;
@@ -1017,7 +723,7 @@ void EightBit::Z80::R(const int r, const uint8_t value) {
 	}
 }
 
-void EightBit::Z80::R2(const int r, const uint8_t value) {
+void EightBit::Z80::R2(const int r, const uint8_t value) noexcept {
 	switch (r) {
 	case 0:
 		B() = value;
@@ -1048,7 +754,7 @@ void EightBit::Z80::R2(const int r, const uint8_t value) {
 	}
 }
 
-int EightBit::Z80::step() {
+int EightBit::Z80::step() noexcept {
 	resetCycles();
 	ExecutingInstruction.fire(*this);
 	if (LIKELY(powered())) {
@@ -1075,7 +781,7 @@ int EightBit::Z80::step() {
 	return cycles();
 }
 
-int EightBit::Z80::execute() {
+int EightBit::Z80::execute() noexcept {
 
 	const auto& decoded = getDecodedOpcode(opcode());
 
@@ -1097,7 +803,7 @@ int EightBit::Z80::execute() {
 	return cycles();
 }
 
-void EightBit::Z80::executeCB(const int x, const int y, const int z) {
+void EightBit::Z80::executeCB(const int x, const int y, const int z) noexcept {
 
 	const bool memoryZ = z == 6;
 	const bool indirect = (!displaced() && memoryZ) || displaced();
@@ -1170,7 +876,7 @@ void EightBit::Z80::executeCB(const int x, const int y, const int z) {
 	}
 }
 
-void EightBit::Z80::executeED(const int x, const int y, const int z, const int p, const int q) {
+void EightBit::Z80::executeED(const int x, const int y, const int z, const int p, const int q) noexcept {
 
 	switch (x) {
 	case 0:
@@ -1385,7 +1091,7 @@ void EightBit::Z80::executeED(const int x, const int y, const int z, const int p
 	}
 }
 
-void EightBit::Z80::executeOther(const int x, const int y, const int z, const int p, const int q) {
+void EightBit::Z80::executeOther(const int x, const int y, const int z, const int p, const int q) noexcept {
 	const bool memoryY = y == 6;
 	const bool memoryZ = z == 6;
 	switch (x) {
diff --git a/Z80/test/Board.cpp b/Z80/test/Board.cpp
index f086bc9..fe4c845 100644
--- a/Z80/test/Board.cpp
+++ b/Z80/test/Board.cpp
@@ -4,7 +4,7 @@
 Board::Board(const Configuration& configuration)
 : m_configuration(configuration) {}
 
-void Board::raisePOWER() {
+void Board::raisePOWER() noexcept {
 	EightBit::Bus::raisePOWER();
 	CPU().raisePOWER();
 	CPU().raiseRESET();
diff --git a/Z80/test/Board.h b/Z80/test/Board.h
index 6cf9d13..b78d942 100644
--- a/Z80/test/Board.h
+++ b/Z80/test/Board.h
@@ -18,7 +18,7 @@ public:
 
 	EightBit::Z80& CPU() noexcept { return m_cpu; }
 
-	void raisePOWER() final;
+	void raisePOWER() noexcept final;
 	void lowerPOWER() noexcept final;
 
 	void initialise() final;
diff --git a/inc/BigEndianProcessor.h b/inc/BigEndianProcessor.h
index b462e1f..9d3faa8 100644
--- a/inc/BigEndianProcessor.h
+++ b/inc/BigEndianProcessor.h
@@ -16,15 +16,15 @@ namespace EightBit {
 	protected:
 		BigEndianProcessor(Bus& memory);
 
-		[[nodiscard]] register16_t getWord() override;
-		void setWord(register16_t value) override;
+		[[nodiscard]] register16_t getWord() noexcept override;
+		void setWord(register16_t value) noexcept override;
 
-		[[nodiscard]] register16_t getWordPaged(uint8_t page, uint8_t offset) override;
-		void setWordPaged(uint8_t page, uint8_t offset, register16_t value) override;
+		[[nodiscard]] register16_t getWordPaged(uint8_t page, uint8_t offset) noexcept override;
+		void setWordPaged(uint8_t page, uint8_t offset, register16_t value) noexcept override;
 
-		[[nodiscard]] register16_t fetchWord() final;
+		[[nodiscard]] register16_t fetchWord() noexcept final;
 
-		void pushWord(register16_t value) final;
-		[[nodiscard]] register16_t popWord() final;
+		void pushWord(register16_t value) noexcept final;
+		[[nodiscard]] register16_t popWord() noexcept final;
 	};
 }
diff --git a/inc/Bus.h b/inc/Bus.h
index ec15630..cdec80d 100644
--- a/inc/Bus.h
+++ b/inc/Bus.h
@@ -33,21 +33,21 @@ namespace EightBit {
 		virtual void poke(const uint16_t address, const uint8_t value) noexcept { reference(address) = value; }
 		void poke(const register16_t address, const uint8_t value) noexcept { poke(address.word, value); }
 
-		[[nodiscard]] uint8_t read();
+		[[nodiscard]] uint8_t read() noexcept;
 		template<class T> [[nodiscard]] auto read(const T address) {
 			ADDRESS() = address;
 			return read();
 		}
 
-		void write();
-		void write(uint8_t value);
-		template<class T> void write(const T offset, const uint8_t value) {
+		void write() noexcept;
+		void write(uint8_t value) noexcept;
+		template<class T> void write(const T offset, const uint8_t value) noexcept {
 			ADDRESS() = offset;
 			write(value);
 		}
 
-		virtual void raisePOWER();
-		virtual void lowerPOWER();
+		virtual void raisePOWER() noexcept;
+		virtual void lowerPOWER() noexcept;
 
 		virtual void initialise() = 0;
 
diff --git a/inc/ClockedChip.h b/inc/ClockedChip.h
index 979579f..c5c5693 100644
--- a/inc/ClockedChip.h
+++ b/inc/ClockedChip.h
@@ -16,13 +16,17 @@ namespace EightBit {
 
 		[[nodiscard]] constexpr auto cycles() const noexcept { return m_cycles; }
 
-		void tick(int extra);
-		void tick();
+		void tick(int extra = 1) noexcept {
+			for (int i = 0; i < extra; ++i) {
+				++m_cycles;
+				Ticked.fire();
+			}
+		}
 
 	protected:
 		ClockedChip() noexcept = default;
 
-		void resetCycles() noexcept;
+		constexpr void resetCycles() noexcept { m_cycles = 0; }
 
 	private:
 		int m_cycles = 0;
diff --git a/inc/Device.h b/inc/Device.h
index d9bd85b..e1d63cd 100644
--- a/inc/Device.h
+++ b/inc/Device.h
@@ -10,17 +10,17 @@
 	Signal<EventArgs> Lowered ## name;
 
 #define DECLARE_PIN_LEVEL_RAISE(name) \
-	virtual void raise ## name();
+	virtual void raise ## name() noexcept;
 
 #define DECLARE_PIN_LEVEL_LOWER(name) \
-	virtual void lower ## name();
+	virtual void lower ## name() noexcept;
 
 #define DECLARE_PIN_LEVEL_CHANGERS(name) \
 	DECLARE_PIN_LEVEL_RAISE(name) \
 	DECLARE_PIN_LEVEL_LOWER(name)
 
 #define DEFINE_PIN_LEVEL_RAISE(name, within) \
-	void EightBit:: within ::raise ## name() { \
+	void EightBit:: within ::raise ## name() noexcept { \
 		if (lowered( name ())) { \
 			Raising ## name.fire(); \
 			raise( name ()); \
@@ -29,7 +29,7 @@
 	}
 
 #define DEFINE_PIN_LEVEL_LOWER(name, within) \
-	void EightBit:: within ::lower ## name() { \
+	void EightBit:: within ::lower ## name() noexcept { \
 		if (raised( name ())) { \
 			Lowering ## name.fire(); \
 			lower( name ()); \
diff --git a/inc/IntelProcessor.h b/inc/IntelProcessor.h
index 4baaff7..0498beb 100644
--- a/inc/IntelProcessor.h
+++ b/inc/IntelProcessor.h
@@ -10,7 +10,7 @@
 #include "EightBitCompilerDefinitions.h"
 
 #define NON_CONST_ACCESSOR(accessor, type) \
-	[[nodiscard]] auto& accessor() noexcept { \
+	[[nodiscard]] constexpr auto& accessor() noexcept { \
 		const auto& consted = *this; \
 		const auto& reference = consted.accessor(); \
 		return const_cast<type&>(reference); \
@@ -140,25 +140,25 @@ namespace EightBit {
 			return calculateHalfCarry(m_halfCarryTableSub, before, value, calculation);
 		}
 
-		void handleRESET() override;
+		void handleRESET() noexcept override;
 
-		void push(uint8_t value) final;
-		[[nodiscard]] uint8_t pop() final;
+		void push(uint8_t value) noexcept final;
+		[[nodiscard]] uint8_t pop() noexcept final;
 
 		//
 
-		[[nodiscard]] register16_t getWord() final;
-		void setWord(register16_t value) final;
+		[[nodiscard]] register16_t getWord() noexcept final;
+		void setWord(register16_t value) noexcept final;
 
 		//
 
-		virtual void restart(uint8_t address);
-		virtual int callConditional(int condition);
-		virtual int jumpConditional(int condition);
-		virtual int returnConditional(int condition);
-		virtual void jr(int8_t offset);
-		virtual int jrConditional(int condition);
-		void ret() override;
+		virtual void restart(uint8_t address) noexcept;
+		virtual int callConditional(int condition) noexcept;
+		virtual int jumpConditional(int condition) noexcept;
+		virtual int returnConditional(int condition) noexcept;
+		virtual void jr(int8_t offset) noexcept;
+		virtual int jrConditional(int condition) noexcept;
+		void ret() noexcept override;
 
 		void resetWorkingRegisters();
 
diff --git a/inc/LittleEndianProcessor.h b/inc/LittleEndianProcessor.h
index 1da3158..1ba3c63 100644
--- a/inc/LittleEndianProcessor.h
+++ b/inc/LittleEndianProcessor.h
@@ -17,15 +17,15 @@ namespace EightBit {
 	protected:
 		LittleEndianProcessor(Bus& memory);
 
-		[[nodiscard]] register16_t getWord() override;
-		void setWord(register16_t value) override;
+		[[nodiscard]] register16_t getWord() noexcept override;
+		void setWord(register16_t value) noexcept override;
 
-		[[nodiscard]] register16_t getWordPaged(uint8_t page, uint8_t offset) override;
-		void setWordPaged(uint8_t page, uint8_t offset, register16_t value) override;
+		[[nodiscard]] register16_t getWordPaged(uint8_t page, uint8_t offset) noexcept override;
+		void setWordPaged(uint8_t page, uint8_t offset, register16_t value) noexcept override;
 
-		[[nodiscard]] register16_t fetchWord() final;
+		[[nodiscard]] register16_t fetchWord() noexcept final;
 
-		void pushWord(register16_t value) override;
-		[[nodiscard]] register16_t popWord() override;
+		void pushWord(register16_t value) noexcept override;
+		[[nodiscard]] register16_t popWord() noexcept override;
 	};
 }
diff --git a/inc/Processor.h b/inc/Processor.h
index a5832c7..3901053 100644
--- a/inc/Processor.h
+++ b/inc/Processor.h
@@ -29,10 +29,10 @@ namespace EightBit {
 		[[nodiscard]] constexpr auto& PC() noexcept { return m_pc; }
 		[[nodiscard]] constexpr const auto& PC() const noexcept { return m_pc; }
 
-		int run(int limit);
-		virtual int step() = 0;
-		virtual int execute() = 0;
-		int execute(uint8_t value);
+		int run(int limit) noexcept;
+		virtual int step() noexcept = 0;
+		virtual int execute() noexcept = 0;
+		int execute(uint8_t value) noexcept;
 
 		[[nodiscard]] virtual register16_t peekWord(register16_t address) noexcept = 0;
 		virtual void pokeWord(register16_t address, register16_t value) noexcept = 0;
@@ -46,44 +46,44 @@ namespace EightBit {
 		[[nodiscard]] constexpr auto& opcode() noexcept { return m_opcode; }
 		[[nodiscard]] constexpr auto& BUS() noexcept { return m_bus; }
 
-		virtual void handleRESET();
-		virtual void handleINT();
+		virtual void handleRESET() noexcept;
+		virtual void handleINT() noexcept;
 
-		void memoryWrite(register16_t address, uint8_t data);
-		void memoryWrite(register16_t address);
-		void memoryWrite(uint8_t data);
-		virtual void memoryWrite();
-		virtual void busWrite();
+		void memoryWrite(register16_t address, uint8_t data) noexcept;
+		void memoryWrite(register16_t address) noexcept;
+		void memoryWrite(uint8_t data) noexcept;
+		virtual void memoryWrite() noexcept;
+		virtual void busWrite() noexcept;
 
-		uint8_t memoryRead(register16_t address);
-		virtual uint8_t memoryRead();
-		virtual uint8_t busRead();
+		uint8_t memoryRead(register16_t address) noexcept;
+		virtual uint8_t memoryRead() noexcept;
+		virtual uint8_t busRead() noexcept;
 
-		uint8_t getBytePaged(uint8_t page, uint8_t offset);
-		void setBytePaged(uint8_t page, uint8_t offset, uint8_t value);
+		uint8_t getBytePaged(uint8_t page, uint8_t offset) noexcept;
+		void setBytePaged(uint8_t page, uint8_t offset, uint8_t value) noexcept;
 
-		uint8_t fetchByte();
+		uint8_t fetchByte() noexcept;
 
-		[[nodiscard]] virtual register16_t getWord() = 0;
-		virtual void setWord(register16_t value) = 0;
+		[[nodiscard]] virtual register16_t getWord() noexcept = 0;
+		virtual void setWord(register16_t value) noexcept = 0;
 
-		[[nodiscard]] virtual register16_t getWordPaged(uint8_t page, uint8_t offset) = 0;
-		virtual void setWordPaged(uint8_t page, uint8_t offset, register16_t value) = 0;
+		[[nodiscard]] virtual register16_t getWordPaged(uint8_t page, uint8_t offset)  noexcept = 0;
+		virtual void setWordPaged(uint8_t page, uint8_t offset, register16_t value)  noexcept = 0;
 
-		[[nodiscard]] virtual register16_t fetchWord() = 0;
+		[[nodiscard]] virtual register16_t fetchWord() noexcept = 0;
 
-		virtual void push(uint8_t value) = 0;
-		[[nodiscard]] virtual uint8_t pop() = 0;
+		virtual void push(uint8_t value) noexcept = 0;
+		[[nodiscard]] virtual uint8_t pop() noexcept = 0;
 
-		virtual void pushWord(register16_t value) = 0;
-		[[nodiscard]] virtual register16_t popWord() = 0;
+		virtual void pushWord(register16_t value) noexcept = 0;
+		[[nodiscard]] virtual register16_t popWord() noexcept = 0;
 
-		[[nodiscard]] register16_t getWord(register16_t address);
-		void setWord(register16_t address, register16_t value);
+		[[nodiscard]] register16_t getWord(register16_t address) noexcept;
+		void setWord(register16_t address, register16_t value) noexcept;
 
 		void jump(const register16_t destination) noexcept;
-		virtual void call(register16_t destination);
-		virtual void ret();
+		virtual void call(register16_t destination) noexcept;
+		virtual void ret() noexcept;
 
 	private:
 		Bus& m_bus;
diff --git a/inc/Signal.h b/inc/Signal.h
index 699ba58..e566da2 100644
--- a/inc/Signal.h
+++ b/inc/Signal.h
@@ -17,7 +17,7 @@ namespace EightBit {
 			m_delegates.push_back(functor);
 		}
 
-		void fire(T& e = EventArgs::empty()) const {
+		void fire(T& e = EventArgs::empty()) const noexcept {
 			for (auto& delegate : m_delegates)
 				delegate(e);
 		}
diff --git a/inc/TestHarness.h b/inc/TestHarness.h
index cbdf8e9..20cb7cc 100644
--- a/inc/TestHarness.h
+++ b/inc/TestHarness.h
@@ -17,9 +17,8 @@
 namespace EightBit {
 	template<class ConfigurationT, class BoardT> class TestHarness final {
 	public:
-		TestHarness(const ConfigurationT& configuration)
-		: m_board(configuration) {
-		}
+		TestHarness(const ConfigurationT& configuration) noexcept
+		: m_board(configuration) {}
 
 		~TestHarness() {
 			std::cout << std::dec << std::endl;
@@ -55,7 +54,7 @@ namespace EightBit {
 			return (long long)floating;
 		}
 
-		void run() {
+		void run() noexcept {
 			m_startTime = now();
 			m_totalCycles = m_instructions = 0L;
 			m_startHostCycles = currentHostCycles();
diff --git a/src/BigEndianProcessor.cpp b/src/BigEndianProcessor.cpp
index 53d8a99..eeebb90 100644
--- a/src/BigEndianProcessor.cpp
+++ b/src/BigEndianProcessor.cpp
@@ -4,44 +4,44 @@
 EightBit::BigEndianProcessor::BigEndianProcessor(Bus& memory)
 : Processor(memory) {}
 
-EightBit::register16_t EightBit::BigEndianProcessor::getWord() {
+EightBit::register16_t EightBit::BigEndianProcessor::getWord() noexcept {
 	const auto high = memoryRead();
 	++BUS().ADDRESS();
 	const auto low = memoryRead();
 	return { low, high };
 }
 
-void EightBit::BigEndianProcessor::setWord(const register16_t value) {
+void EightBit::BigEndianProcessor::setWord(const register16_t value) noexcept {
 	memoryWrite(value.high);
 	++BUS().ADDRESS();
 	memoryWrite(value.low);
 }
 
-EightBit::register16_t EightBit::BigEndianProcessor::getWordPaged(const uint8_t page, const uint8_t offset) {
+EightBit::register16_t EightBit::BigEndianProcessor::getWordPaged(const uint8_t page, const uint8_t offset) noexcept {
 	const auto high = getBytePaged(page, offset);
 	++BUS().ADDRESS().low;
 	const auto low = memoryRead();
 	return { low, high };
 }
 
-void EightBit::BigEndianProcessor::setWordPaged(const uint8_t page, const uint8_t offset, const register16_t value) {
+void EightBit::BigEndianProcessor::setWordPaged(const uint8_t page, const uint8_t offset, const register16_t value) noexcept {
 	setBytePaged(page, offset, value.high);
 	++BUS().ADDRESS().low;
 	memoryWrite(value.low);
 }
 
-EightBit::register16_t EightBit::BigEndianProcessor::fetchWord() {
+EightBit::register16_t EightBit::BigEndianProcessor::fetchWord() noexcept {
 	const auto high = fetchByte();
 	const auto low = fetchByte();
 	return { low, high };
 }
 
-void EightBit::BigEndianProcessor::pushWord(const register16_t value) {
+void EightBit::BigEndianProcessor::pushWord(const register16_t value) noexcept {
 	push(value.low);
 	push(value.high);
 }
 
-EightBit::register16_t EightBit::BigEndianProcessor::popWord() {
+EightBit::register16_t EightBit::BigEndianProcessor::popWord() noexcept {
 	const auto high = pop();
 	const auto low = pop();
 	return { low, high };
diff --git a/src/Bus.cpp b/src/Bus.cpp
index 1924b79..812868f 100644
--- a/src/Bus.cpp
+++ b/src/Bus.cpp
@@ -4,24 +4,24 @@
 #include "../inc/IntelHexFile.h"
 #include "../inc/EightBitCompilerDefinitions.h"
 
-void EightBit::Bus::raisePOWER() {}
+void EightBit::Bus::raisePOWER() noexcept {}
 
-void EightBit::Bus::lowerPOWER() {}
+void EightBit::Bus::lowerPOWER() noexcept {}
 
-uint8_t EightBit::Bus::read() {
+uint8_t EightBit::Bus::read() noexcept {
 	ReadingByte.fire();
 	const auto returned = DATA() = reference();
 	ReadByte.fire();
 	return returned;
 }
 
-void EightBit::Bus::write() {
+void EightBit::Bus::write() noexcept {
 	WritingByte.fire();
 	reference() = DATA();
 	WrittenByte.fire();
 }
 
-void EightBit::Bus::write(const uint8_t value) {
+void EightBit::Bus::write(const uint8_t value) noexcept {
 	DATA() = value;
 	write();
 }
diff --git a/src/ClockedChip.cpp b/src/ClockedChip.cpp
index 145d757..bb34757 100644
--- a/src/ClockedChip.cpp
+++ b/src/ClockedChip.cpp
@@ -6,20 +6,6 @@ EightBit::ClockedChip::ClockedChip(const ClockedChip& rhs)
 	m_cycles = rhs.m_cycles;
 }
 
-void EightBit::ClockedChip::tick(const int extra) {
-	for (int i = 0; i < extra; ++i)
-		tick();
-}
-
-void EightBit::ClockedChip::tick() {
-	++m_cycles;
-	Ticked.fire();
-}
-
-void EightBit::ClockedChip::resetCycles() noexcept {
-	m_cycles = 0;
-}
-
 bool EightBit::ClockedChip::operator==(const EightBit::ClockedChip& rhs) const {
 	return
 		Device::operator==(rhs)
diff --git a/src/IntelProcessor.cpp b/src/IntelProcessor.cpp
index b2e9baa..56dba9e 100644
--- a/src/IntelProcessor.cpp
+++ b/src/IntelProcessor.cpp
@@ -34,59 +34,59 @@ void EightBit::IntelProcessor::resetWorkingRegisters() {
 
 DEFINE_PIN_LEVEL_CHANGERS(HALT, IntelProcessor);
 
-void EightBit::IntelProcessor::handleRESET() {
+void EightBit::IntelProcessor::handleRESET() noexcept {
 	Processor::handleRESET();
 	PC() = 0;
 }
 
-void EightBit::IntelProcessor::push(const uint8_t value) {
+void EightBit::IntelProcessor::push(const uint8_t value) noexcept {
 	memoryWrite(--SP(), value);
 }
 
-uint8_t EightBit::IntelProcessor::pop() {
+uint8_t EightBit::IntelProcessor::pop() noexcept {
 	return memoryRead(SP()++);
 }
 
-EightBit::register16_t EightBit::IntelProcessor::getWord() {
+EightBit::register16_t EightBit::IntelProcessor::getWord() noexcept {
 	const auto returned = LittleEndianProcessor::getWord();
 	MEMPTR() = BUS().ADDRESS();
 	return returned;
 }
 
-void EightBit::IntelProcessor::setWord(const register16_t value) {
+void EightBit::IntelProcessor::setWord(const register16_t value) noexcept {
 	LittleEndianProcessor::setWord(value);
 	MEMPTR() = BUS().ADDRESS();
 }
 
-void EightBit::IntelProcessor::restart(const uint8_t address) {
+void EightBit::IntelProcessor::restart(const uint8_t address) noexcept {
 	call(MEMPTR() = { address, 0 });
 }
 
-int EightBit::IntelProcessor::callConditional(const int condition) {
+int EightBit::IntelProcessor::callConditional(const int condition) noexcept {
 	MEMPTR() = fetchWord();
 	if (condition)
 		call(MEMPTR());
 	return condition;
 }
 
-int EightBit::IntelProcessor::jumpConditional(const int condition) {
+int EightBit::IntelProcessor::jumpConditional(const int condition) noexcept {
 	MEMPTR() = fetchWord();
 	if (condition)
 		jump(MEMPTR());
 	return condition;
 }
 
-int EightBit::IntelProcessor::returnConditional(const int condition) {
+int EightBit::IntelProcessor::returnConditional(const int condition) noexcept {
 	if (condition)
 		ret();
 	return condition;
 }
 
-void EightBit::IntelProcessor::jr(const int8_t offset) {
+void EightBit::IntelProcessor::jr(const int8_t offset) noexcept {
 	jump(MEMPTR() = PC() + offset);
 }
 
-int EightBit::IntelProcessor::jrConditional(const int condition) {
+int EightBit::IntelProcessor::jrConditional(const int condition) noexcept {
 	const auto offsetAddress = PC()++;
 	if (condition) {
 		const auto offset = memoryRead(offsetAddress);
@@ -95,7 +95,7 @@ int EightBit::IntelProcessor::jrConditional(const int condition) {
 	return condition;
 }
 
-void EightBit::IntelProcessor::ret() {
+void EightBit::IntelProcessor::ret() noexcept {
 	Processor::ret();
 	MEMPTR() = PC();
 }
diff --git a/src/LittleEndianProcessor.cpp b/src/LittleEndianProcessor.cpp
index 271778a..3472b6a 100644
--- a/src/LittleEndianProcessor.cpp
+++ b/src/LittleEndianProcessor.cpp
@@ -7,44 +7,44 @@ EightBit::LittleEndianProcessor::LittleEndianProcessor(Bus& memory)
 EightBit::LittleEndianProcessor::LittleEndianProcessor(const LittleEndianProcessor& rhs)
 : Processor(rhs) {}
 
-EightBit::register16_t EightBit::LittleEndianProcessor::getWord() {
+EightBit::register16_t EightBit::LittleEndianProcessor::getWord() noexcept {
 	const auto low = memoryRead();
 	++BUS().ADDRESS();
 	const auto high = memoryRead();
 	return { low, high };
 }
 
-void EightBit::LittleEndianProcessor::setWord(const register16_t value) {
+void EightBit::LittleEndianProcessor::setWord(const register16_t value) noexcept {
 	memoryWrite(value.low);
 	++BUS().ADDRESS();
 	memoryWrite(value.high);
 }
 
-EightBit::register16_t EightBit::LittleEndianProcessor::getWordPaged(const uint8_t page, const uint8_t offset) {
+EightBit::register16_t EightBit::LittleEndianProcessor::getWordPaged(const uint8_t page, const uint8_t offset) noexcept {
 	const auto low = getBytePaged(page, offset);
 	++BUS().ADDRESS().low;
 	const auto high = memoryRead();
 	return { low, high };
 }
 
-void EightBit::LittleEndianProcessor::setWordPaged(const uint8_t page, const uint8_t offset, const register16_t value) {
+void EightBit::LittleEndianProcessor::setWordPaged(const uint8_t page, const uint8_t offset, const register16_t value) noexcept {
 	setBytePaged(page, offset, value.low);
 	++BUS().ADDRESS().low;
 	memoryWrite(value.high);
 }
 
-EightBit::register16_t EightBit::LittleEndianProcessor::fetchWord() {
+EightBit::register16_t EightBit::LittleEndianProcessor::fetchWord() noexcept {
 	const auto low = fetchByte();
 	const auto high = fetchByte();
 	return { low, high };
 }
 
-void EightBit::LittleEndianProcessor::pushWord(const register16_t value) {
+void EightBit::LittleEndianProcessor::pushWord(const register16_t value) noexcept {
 	push(value.high);
 	push(value.low);
 }
 
-EightBit::register16_t EightBit::LittleEndianProcessor::popWord() {
+EightBit::register16_t EightBit::LittleEndianProcessor::popWord() noexcept {
 	const auto low = pop();
 	const auto high = pop();
 	return { low, high };
diff --git a/src/Processor.cpp b/src/Processor.cpp
index e2b21b5..adbafb2 100644
--- a/src/Processor.cpp
+++ b/src/Processor.cpp
@@ -16,80 +16,80 @@ EightBit::Processor::Processor(const Processor& rhs)
 DEFINE_PIN_LEVEL_CHANGERS(RESET, Processor);
 DEFINE_PIN_LEVEL_CHANGERS(INT, Processor);
 
-void EightBit::Processor::handleRESET() {
+void EightBit::Processor::handleRESET() noexcept {
 	raiseRESET();
 }
 
-void EightBit::Processor::handleINT() {
+void EightBit::Processor::handleINT() noexcept {
 	raiseINT();
 }
 
-void EightBit::Processor::memoryWrite(const register16_t address, const uint8_t data) {
+void EightBit::Processor::memoryWrite(const register16_t address, const uint8_t data) noexcept {
 	BUS().ADDRESS() = address;
 	memoryWrite(data);
 }
 
-void EightBit::Processor::memoryWrite(const register16_t address) {
+void EightBit::Processor::memoryWrite(const register16_t address)  noexcept {
 	BUS().ADDRESS() = address;
 	memoryWrite();
 }
 
-void EightBit::Processor::memoryWrite(const uint8_t data) {
+void EightBit::Processor::memoryWrite(const uint8_t data)  noexcept {
 	BUS().DATA() = data;
 	memoryWrite();
 }
 
-void EightBit::Processor::memoryWrite() {
+void EightBit::Processor::memoryWrite()  noexcept {
 	busWrite();
 }
 
-void EightBit::Processor::busWrite() {
+void EightBit::Processor::busWrite() noexcept {
 	BUS().write();
 }
 
-uint8_t EightBit::Processor::memoryRead(const register16_t address) {
+uint8_t EightBit::Processor::memoryRead(const register16_t address) noexcept {
 	BUS().ADDRESS() = address;
 	return memoryRead();
 }
 
-uint8_t EightBit::Processor::memoryRead() {
+uint8_t EightBit::Processor::memoryRead() noexcept {
 	return busRead();
 }
 
-uint8_t EightBit::Processor::busRead() {
+uint8_t EightBit::Processor::busRead() noexcept {
 	return BUS().read();
 }
 
-uint8_t EightBit::Processor::getBytePaged(const uint8_t page, const uint8_t offset) {
+uint8_t EightBit::Processor::getBytePaged(const uint8_t page, const uint8_t offset) noexcept {
 	return memoryRead(register16_t(offset, page));
 }
 
-void EightBit::Processor::setBytePaged(const uint8_t page, const uint8_t offset, const uint8_t value) {
+void EightBit::Processor::setBytePaged(const uint8_t page, const uint8_t offset, const uint8_t value) noexcept {
 	memoryWrite(register16_t(offset, page), value);
 }
 
-uint8_t EightBit::Processor::fetchByte() {
+uint8_t EightBit::Processor::fetchByte() noexcept {
 	return memoryRead(PC()++);
 }
 
-EightBit::register16_t EightBit::Processor::getWord(const register16_t address) {
+EightBit::register16_t EightBit::Processor::getWord(const register16_t address) noexcept {
 	BUS().ADDRESS() = address;
 	return getWord();
 }
 
-void EightBit::Processor::setWord(const register16_t address, const register16_t value) {
+void EightBit::Processor::setWord(const register16_t address, const register16_t value) noexcept {
 	BUS().ADDRESS() = address;
 	setWord(value);
 }
 
-int EightBit::Processor::run(const int limit) {
+int EightBit::Processor::run(const int limit) noexcept {
 	int current = 0;
 	while (LIKELY(powered() && (current < limit)))
 		current += step();
 	return current;
 }
 
-int EightBit::Processor::execute(const uint8_t value) {
+int EightBit::Processor::execute(const uint8_t value) noexcept {
 	opcode() = value;
 	return execute();
 }
@@ -98,12 +98,12 @@ void EightBit::Processor::jump(const register16_t destination) noexcept {
 	PC() = destination;
 }
 
-void EightBit::Processor::call(const register16_t destination) {
+void EightBit::Processor::call(const register16_t destination) noexcept {
 	pushWord(PC());
 	jump(destination);
 }
 
-void EightBit::Processor::ret() {
+void EightBit::Processor::ret() noexcept {
 	jump(popWord());
 }