diff --git a/MC6809/inc/mc6809.h b/MC6809/inc/mc6809.h
index 999bb98..4ea7949 100644
--- a/MC6809/inc/mc6809.h
+++ b/MC6809/inc/mc6809.h
@@ -112,7 +112,7 @@ namespace EightBit {
 		// Default push/pop handlers
 
 		void push(uint8_t value) noexcept final;
-		[[nodiscard]] uint8_t pop() noexcept final;
+		void pop() noexcept final;
 
 		// Interrupt (etc.) handlers
 
@@ -121,8 +121,13 @@ namespace EightBit {
 
 		// Bus reader/writers
 
-		void busWrite() noexcept final;
-		uint8_t busRead() noexcept final;
+		using Processor::memoryRead;
+		using Processor::memoryWrite;
+		void memoryRead() noexcept override;
+		void memoryWrite() noexcept override;
+
+		void busWrite() noexcept;
+		uint8_t busRead() noexcept;
 
 		void call(register16_t destination) noexcept final;
 		void ret() noexcept final;
@@ -236,7 +241,7 @@ namespace EightBit {
 		// Flag adjustment
 
 		template<class T> constexpr void adjustZero(const T datum) { CC() = clearBit(CC(), ZF, datum); }
-		constexpr void adjustZero(const register16_t datum) { CC() = clearBit(CC(), ZF, datum.word); }
+		constexpr void adjustZero(const register16_t datum) { CC() = clearBit(CC(), ZF, datum.joined); }
 		constexpr void adjustNegative(const uint8_t datum) { CC() = setBit(CC(), NF, datum & Bit7); }
 		constexpr void adjustNegative(const register16_t datum) { adjustNegative(datum.high); }
 		constexpr void adjustNegative(const uint16_t datum) { adjustNegative(register16_t(datum)); }
@@ -248,11 +253,11 @@ namespace EightBit {
 
 		constexpr void adjustCarry(const uint16_t datum) { CC() = setBit(CC(), CF, datum & Bit8); }		// 8-bit addition
 		constexpr void adjustCarry(const uint32_t datum) { CC() = setBit(CC(), CF, datum & Bit16); }		// 16-bit addition
-		constexpr void adjustCarry(const register16_t datum) { adjustCarry(datum.word); }
+		constexpr void adjustCarry(const register16_t datum) { adjustCarry(datum.joined); }
 
 		constexpr void adjustBorrow(const uint16_t datum) { CC() = clearBit(CC(), CF, datum & Bit8); }		// 8-bit subtraction
 		constexpr void adjustBorrow(const uint32_t datum) { CC() = clearBit(CC(), CF, datum & Bit16); }	// 16-bit subtraction
-		constexpr void adjustBorrow(const register16_t datum) { adjustBorrow(datum.word); }
+		constexpr void adjustBorrow(const register16_t datum) { adjustBorrow(datum.joined); }
 
 		constexpr void adjustOverflow(const uint8_t before, const uint8_t data, const register16_t after) {
 			const uint8_t lowAfter = after.low;
@@ -267,7 +272,7 @@ namespace EightBit {
 		}
 
 		constexpr void adjustOverflow(const register16_t before, const register16_t data, const register16_t after) {
-			adjustOverflow(before.word, data.word, after.word);
+			adjustOverflow(before.joined, data.joined, after.joined);
 		}
 
 		constexpr void adjustHalfCarry(const uint8_t before, const uint8_t data, const uint8_t after) {
@@ -290,7 +295,7 @@ namespace EightBit {
 		}
 
 		constexpr void adjustAddition(const register16_t before, const register16_t data, const uint32_t after) {
-			adjustAddition(before.word, data.word, after);
+			adjustAddition(before.joined, data.joined, after);
 		}
 
 		constexpr void adjustSubtraction(const uint8_t before, const uint8_t data, const register16_t after) {
@@ -308,7 +313,7 @@ namespace EightBit {
 		}
 
 		constexpr void adjustSubtraction(const register16_t before, const register16_t data, const uint32_t after) {
-			adjustSubtraction(before.word, data.word, after);
+			adjustSubtraction(before.joined, data.joined, after);
 		}
 
 
diff --git a/MC6809/src/Disassembly.cpp b/MC6809/src/Disassembly.cpp
index ffe76ef..0e35418 100644
--- a/MC6809/src/Disassembly.cpp
+++ b/MC6809/src/Disassembly.cpp
@@ -43,7 +43,7 @@ std::string EightBit::Disassembly::dump_RelativeValue(int8_t value) {
 }
 
 std::string EightBit::Disassembly::dump_WordValue(register16_t value) {
-	return dump_WordValue(value.word);
+	return dump_WordValue(value.joined);
 }
 
 std::string EightBit::Disassembly::dump_WordValue(uint16_t value) {
@@ -53,7 +53,7 @@ std::string EightBit::Disassembly::dump_WordValue(uint16_t value) {
 }
 
 std::string EightBit::Disassembly::dump_RelativeValue(register16_t value) {
-	return dump_RelativeValue((int16_t)value.word);
+	return dump_RelativeValue((int16_t)value.joined);
 }
 
 std::string EightBit::Disassembly::dump_RelativeValue(int16_t value) {
@@ -69,7 +69,7 @@ std::string EightBit::Disassembly::trace() {
 }
 
 std::string EightBit::Disassembly::trace(register16_t current) {
-	return trace(current.word);
+	return trace(current.joined);
 }
 
 std::string EightBit::Disassembly::trace(uint16_t current) {
@@ -99,7 +99,7 @@ std::string EightBit::Disassembly::disassemble() {
 }
 
 std::string EightBit::Disassembly::disassemble(register16_t current) {
-	return disassemble(current.word);
+	return disassemble(current.joined);
 }
 
 bool EightBit::Disassembly::ignore() {
@@ -883,7 +883,7 @@ uint8_t EightBit::Disassembly::getByte(uint16_t address) {
 }
 
 uint16_t EightBit::Disassembly::getShort(uint16_t address) {
-	return CPU().peekShort(address).word;
+	return CPU().peekShort(address).joined;
 }
 
 //
diff --git a/MC6809/src/mc6809.cpp b/MC6809/src/mc6809.cpp
index 38c5ec8..325e83e 100644
--- a/MC6809/src/mc6809.cpp
+++ b/MC6809/src/mc6809.cpp
@@ -36,7 +36,7 @@ void EightBit::mc6809::poweredStep() noexcept {
 		else if (UNLIKELY(lowered(INT()) && !interruptMasked()))
 			handleINT();
 		else
-			BigEndianProcessor::execute(fetchByte());
+			BigEndianProcessor::execute(fetchInstruction());
 	//}
 	//ExecutedInstruction.fire(*this);
 	//assert(cycles() > 0);
@@ -62,7 +62,7 @@ void EightBit::mc6809::handleRESET() noexcept {
 	memoryRead();
 	memoryRead();
 	memoryRead();
-	jump(getShort());
+	getPagedInto(PC());
 	eat();
 }
 
@@ -77,7 +77,7 @@ void EightBit::mc6809::handleNMI() noexcept {
 	eat();
 	CC() = setBit(CC(), IF);	// Disable IRQ
 	CC() = setBit(CC(), FF);	// Disable FIRQ
-	jump(Processor::getWordPaged(0xff, NMIvector));
+	Processor::getPagedInto(0xff, NMIvector, PC());
 	eat();
 }
 
@@ -91,7 +91,7 @@ void EightBit::mc6809::handleINT() noexcept {
 	saveEntireRegisterState();
 	eat();
 	CC() = setBit(CC(), IF);	// Disable IRQ
-	jump(Processor::getWordPaged(0xff, IRQvector));
+	Processor::getPagedInto(0xff, IRQvector, PC());
 	eat();
 }
 
@@ -106,12 +106,20 @@ void EightBit::mc6809::handleFIRQ() noexcept {
 	eat();
 	CC() = setBit(CC(), IF);	// Disable IRQ
 	CC() = setBit(CC(), FF);	// Disable FIRQ
-	jump(Processor::getWordPaged(0xff, FIRQvector));
+	Processor::getPagedInto(0xff, FIRQvector, PC());
 	eat();
 }
 
 //
 
+void EightBit::mc6809::memoryRead() noexcept {
+	busRead();
+}
+
+void EightBit::mc6809::memoryWrite() noexcept {
+	busWrite();
+}
+
 void EightBit::mc6809::busWrite() noexcept {
 	tick();
 	lowerRW();
@@ -121,7 +129,8 @@ void EightBit::mc6809::busWrite() noexcept {
 uint8_t EightBit::mc6809::busRead() noexcept {
 	tick();
 	raiseRW();
-	return BigEndianProcessor::busRead();
+	BigEndianProcessor::busRead();
+	return BUS().DATA();
 }
 
 //
@@ -129,7 +138,7 @@ uint8_t EightBit::mc6809::busRead() noexcept {
 void EightBit::mc6809::call(register16_t destination) noexcept {
 	memoryRead(destination);
 	eat();
-	BigEndianProcessor::pushWord(PC());
+	pushShort(PC());
 	jump(destination);
 }
 
@@ -162,8 +171,8 @@ void EightBit::mc6809::executeUnprefixed() {
 
 	switch (opcode()) {
 
-	case 0x10:	m_prefix10 = true;	Processor::execute(fetchByte());	break;
-	case 0x11:	m_prefix11 = true;	Processor::execute(fetchByte());	break;
+	case 0x10:	m_prefix10 = true;	Processor::execute(fetchInstruction());	break;
+	case 0x11:	m_prefix11 = true;	Processor::execute(fetchInstruction());	break;
 
 	// ABX
 	case 0x3a:	memoryRead(); X() += B(); eat();						break;		// ABX (inherent)
@@ -447,19 +456,19 @@ void EightBit::mc6809::executeUnprefixed() {
 	case 0xf7:	memoryWrite(Address_extended(), through(B()));			break;		// ST (STB extended)
 
 	// STD
-	case 0xdd:	Processor::setWord(Address_direct(), through(D()));		break;		// ST (STD direct)
-	case 0xed:	Processor::setWord(Address_indexed(), through(D()));	break;		// ST (STD indexed)
-	case 0xfd:	Processor::setWord(Address_extended(), through(D()));	break;		// ST (STD extended)
+	case 0xdd:	Processor::setShort(Address_direct(), through(D()));		break;		// ST (STD direct)
+	case 0xed:	Processor::setShort(Address_indexed(), through(D()));	break;		// ST (STD indexed)
+	case 0xfd:	Processor::setShort(Address_extended(), through(D()));	break;		// ST (STD extended)
 
 	// STU
-	case 0xdf:	Processor::setWord(Address_direct(), through(U()));		break;		// ST (STU direct)
-	case 0xef:	Processor::setWord(Address_indexed(), through(U()));	break;		// ST (STU indexed)
-	case 0xff:	Processor::setWord(Address_extended(), through(U()));	break;		// ST (STU extended)
+	case 0xdf:	Processor::setShort(Address_direct(), through(U()));		break;		// ST (STU direct)
+	case 0xef:	Processor::setShort(Address_indexed(), through(U()));	break;		// ST (STU indexed)
+	case 0xff:	Processor::setShort(Address_extended(), through(U()));	break;		// ST (STU extended)
 
 	// STX
-	case 0x9f:	Processor::setWord(Address_direct(), through(X()));		break;		// ST (STX direct)
-	case 0xaf:	Processor::setWord(Address_indexed(), through(X()));	break;		// ST (STX indexed)
-	case 0xbf:	Processor::setWord(Address_extended(), through(X()));	break;		// ST (STX extended)
+	case 0x9f:	Processor::setShort(Address_direct(), through(X()));		break;		// ST (STX direct)
+	case 0xaf:	Processor::setShort(Address_indexed(), through(X()));	break;		// ST (STX indexed)
+	case 0xbf:	Processor::setShort(Address_extended(), through(X()));	break;		// ST (STX extended)
 
 	// SUB
 
@@ -579,14 +588,14 @@ void EightBit::mc6809::execute10() {
 	case 0x2f:	branchLong(LE());										break;		// BLE (LBLE relative)
 
 	// STS
-	case 0xdf:	Processor::setWord(Address_direct(), through(S()));		break;		// ST (STS direct)
-	case 0xef:	Processor::setWord(Address_indexed(), through(S()));	break;		// ST (STS indexed)
-	case 0xff:	Processor::setWord(Address_extended(), through(S()));	break;		// ST (STS extended)
+	case 0xdf:	Processor::setShort(Address_direct(), through(S()));		break;		// ST (STS direct)
+	case 0xef:	Processor::setShort(Address_indexed(), through(S()));	break;		// ST (STS indexed)
+	case 0xff:	Processor::setShort(Address_extended(), through(S()));	break;		// ST (STS extended)
 
 	// STY
-	case 0x9f:	Processor::setWord(Address_direct(), through(Y()));		break;		// ST (STY direct)
-	case 0xaf:	Processor::setWord(Address_indexed(), through(Y()));	break;		// ST (STY indexed)
-	case 0xbf:	Processor::setWord(Address_extended(), through(Y()));	break;		// ST (STY extended)
+	case 0x9f:	Processor::setShort(Address_direct(), through(Y()));		break;		// ST (STY direct)
+	case 0xaf:	Processor::setShort(Address_indexed(), through(Y()));	break;		// ST (STY indexed)
+	case 0xbf:	Processor::setShort(Address_extended(), through(Y()));	break;		// ST (STY extended)
 
 	// SWI
 	case 0x3f:	memoryRead(); swi2();									break;		// SWI (SWI2 inherent)
@@ -631,8 +640,8 @@ void EightBit::mc6809::push(const uint8_t value) noexcept {
 	pushS(value);
 }
 
-uint8_t EightBit::mc6809::pop() noexcept {
-	return popS();
+void EightBit::mc6809::pop() noexcept {
+	(void)popS();
 }
 
 void EightBit::mc6809::push(register16_t& stack, const uint8_t value) noexcept {
@@ -640,7 +649,8 @@ void EightBit::mc6809::push(register16_t& stack, const uint8_t value) noexcept {
 }
 
 uint8_t EightBit::mc6809::pop(register16_t& stack) noexcept {
-	return memoryRead(stack++);
+	memoryRead(stack++);
+	return BUS().DATA();
 }
 
 //
@@ -663,23 +673,27 @@ EightBit::register16_t& EightBit::mc6809::RR(const int which) {
 }
 
 EightBit::register16_t EightBit::mc6809::Address_relative_byte() {
-	const auto address = PC() + (int8_t)fetchByte();
+	fetchByte();
+	const auto address = PC() + (int8_t)BUS().DATA();
 	eat();
 	return address;
 }
 
 EightBit::register16_t EightBit::mc6809::Address_relative_word() {
-	return PC() + (int16_t)fetchWord().word;
+	fetchShort();
+	return PC() + (int16_t)intermediate().joined;
 }
 
 EightBit::register16_t EightBit::mc6809::Address_direct() {
-	const auto offset = fetchByte();
+	fetchByte();
+	const auto offset = BUS().DATA();
 	eat();
 	return register16_t(offset, DP());
 }
 
 EightBit::register16_t EightBit::mc6809::Address_indexed() {
-	const auto type = fetchByte();
+	fetchByte();
+	const auto type = BUS().DATA();
 	auto& r = RR((type & (Bit6 | Bit5)) >> 5);
 
 	register16_t address = Mask16;
@@ -725,11 +739,13 @@ EightBit::register16_t EightBit::mc6809::Address_indexed() {
 			eat();
 			break;
 		case 0b1000:	// n,R (eight-bit)
-			address = r + (int8_t)fetchByte();
+			fetchByte();
+			address = r + (int8_t)BUS().DATA();
 			eat();
 			break;
 		case 0b1001:	// n,R (sixteen-bit)
-			address = r + (int16_t)fetchWord().word;
+			fetchShort();
+			address = r + (int16_t)intermediate().joined;
 			memoryRead(PC());
 			eat(2);
 			break;
@@ -757,7 +773,8 @@ EightBit::register16_t EightBit::mc6809::Address_indexed() {
 			UNREACHABLE;
 		}
 		if (indirect) {
-			address = Processor::getShort(address);
+			getShort(address);
+			address = intermediate();
 			eat();
 		}
 	} else {
@@ -770,45 +787,53 @@ EightBit::register16_t EightBit::mc6809::Address_indexed() {
 }
 
 EightBit::register16_t EightBit::mc6809::Address_extended() {
-	const auto ea = fetchWord();
+	fetchShort();
 	eat();
-	return ea;
+	return intermediate();
 }
 
 //
 
 uint8_t EightBit::mc6809::AM_immediate_byte() {
-	return fetchByte();
+	fetchByte();
+	return BUS().DATA();
 }
 
 uint8_t EightBit::mc6809::AM_direct_byte() {
-	return memoryRead(Address_direct());
+	memoryRead(Address_direct());
+	return BUS().DATA();
 }
 
 uint8_t EightBit::mc6809::AM_indexed_byte() {
-	return memoryRead(Address_indexed());
+	memoryRead(Address_indexed());
+	return BUS().DATA();
 }
 
 uint8_t EightBit::mc6809::AM_extended_byte() {
-	return memoryRead(Address_extended());
+	memoryRead(Address_extended());
+	return BUS().DATA();
 }
 
 //
 
 EightBit::register16_t EightBit::mc6809::AM_immediate_word() {
-	return fetchWord();
+	fetchShort();
+	return intermediate();
 }
 
 EightBit::register16_t EightBit::mc6809::AM_direct_word() {
-	return Processor::getShort(Address_direct());
+	getShort(Address_direct());
+	return intermediate();
 }
 
 EightBit::register16_t EightBit::mc6809::AM_indexed_word() {
-	return Processor::getShort(Address_indexed());
+	getShort(Address_indexed());
+	return intermediate();
 }
 
 EightBit::register16_t EightBit::mc6809::AM_extended_word() {
-	return Processor::getShort(Address_extended());
+	getShort(Address_extended());
+	return intermediate();
 }
 
 //
@@ -844,7 +869,7 @@ uint8_t EightBit::mc6809::add(const uint8_t operand, const uint8_t data, const u
 }
 
 EightBit::register16_t EightBit::mc6809::add(const register16_t operand, const register16_t data) {
-	const uint32_t addition = operand.word + data.word;
+	const uint32_t addition = operand.joined + data.joined;
 	adjustAddition(operand, data, addition);
 	eat();
 	return addition & Mask16;
@@ -1087,21 +1112,21 @@ void EightBit::mc6809::swi() {
 	saveEntireRegisterState();
 	CC() = setBit(CC(), IF);	// Disable IRQ
 	CC() = setBit(CC(), FF);	// Disable FIRQ
-	jump(Processor::getWordPaged(0xff, SWIvector));
+	Processor::getPagedInto(0xff, SWIvector, PC());
 	eat();
 }
 
 void EightBit::mc6809::swi2() {
 	eat();
 	saveEntireRegisterState();
-	jump(Processor::getWordPaged(0xff, SWI2vector));
+	Processor::getPagedInto(0xff, SWI2vector, PC());
 	eat();
 }
 
 void EightBit::mc6809::swi3() {
 	eat();
 	saveEntireRegisterState();
-	jump(Processor::getWordPaged(0xff, SWI3vector));
+	Processor::getPagedInto(0xff, SWI3vector, PC());
 	eat();
 }
 
@@ -1137,7 +1162,7 @@ uint8_t EightBit::mc6809::sub(const uint8_t operand, const uint8_t data, const u
 }
 
 EightBit::register16_t EightBit::mc6809::sub(const register16_t operand, const register16_t data) {
-	const uint32_t subtraction = operand.word - data.word;
+	const uint32_t subtraction = operand.joined - data.joined;
 	adjustSubtraction(operand, data, subtraction);
 	eat();
 	return subtraction & Mask16;
diff --git a/MC6809/test/Board.cpp b/MC6809/test/Board.cpp
index 6d2157e..30354e3 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) {
@@ -40,7 +40,7 @@ void Board::lowerPOWER() {
 	EightBit::Bus::lowerPOWER();
 }
 
-void Board::initialise() {
+void Board::initialise() noexcept {
 
 	// Load our BASIC interpreter
 	const auto directory = m_configuration.getRomDirectory() + "\\";
@@ -53,14 +53,14 @@ void Board::initialise() {
 	});
 
 	// Marshal data from memory -> ACIA
-	WrittenByte.connect([this] (EightBit::EventArgs&) {
+	CPU().WrittenMemory.connect([this] (EightBit::EventArgs&) {
 		updateAciaPins();
 		if (ACIA().selected())
 			accessAcia();
 	});
 
 	// Marshal data from ACIA -> memory
-	ReadingByte.connect([this] (EightBit::EventArgs&) {
+	CPU().ReadingMemory.connect([this] (EightBit::EventArgs&) {
 		updateAciaPins();
 		if (accessAcia())
 			poke(ACIA().DATA());
@@ -84,7 +84,7 @@ void Board::initialise() {
 			m_profiler.addInstruction(peek(cpu.PC()));
 		});
 		m_cpu.ExecutedInstruction.connect([this](EightBit::mc6809& cpu) {
-			m_profiler.addAddress(cpu.PC().word, cpu.cycles());
+			m_profiler.addAddress(cpu.PC().joined, cpu.cycles());
 		});
 	}
 
@@ -111,27 +111,31 @@ void Board::initialise() {
 	}
 }
 
-EightBit::MemoryMapping Board::mapping(uint16_t address) {
+const EightBit::MemoryMapping& Board::mapping(uint16_t address) noexcept {
 
 	if (address < 0x8000)
-		return { m_ram, 0x0000, EightBit::Chip::Mask16, EightBit::MemoryMapping::AccessLevel::ReadWrite };
+		return m_ramMapping;
+		//return { m_ram, 0x0000, EightBit::Chip::Mask16, EightBit::MemoryMapping::AccessLevel::ReadWrite };
 
 	if (address < 0xa000)
-		return { m_unused2000, 0x8000, EightBit::Chip::Mask16, EightBit::MemoryMapping::AccessLevel::ReadOnly };
+		return m_unused2000Mapping;
+		//return { m_unused2000, 0x8000, EightBit::Chip::Mask16, EightBit::MemoryMapping::AccessLevel::ReadOnly };
 
 	if (address < 0xc000)
-		return { m_io, 0xa000, EightBit::Chip::Mask16, EightBit::MemoryMapping::AccessLevel::ReadWrite };
+		return m_ioMapping;
+		//return { m_io, 0xa000, EightBit::Chip::Mask16, EightBit::MemoryMapping::AccessLevel::ReadWrite };
 
-	return { m_rom, 0xc000, EightBit::Chip::Mask16, EightBit::MemoryMapping::AccessLevel::ReadOnly };
+	return m_romMapping;
+	//return { m_rom, 0xc000, EightBit::Chip::Mask16, EightBit::MemoryMapping::AccessLevel::ReadOnly };
 }
 
 void Board::updateAciaPins() {
 	ACIA().DATA() = DATA();
 	EightBit::Device::match(ACIA().RW(), CPU().RW());
-	EightBit::Device::match(ACIA().RS(), ADDRESS().word & EightBit::Chip::Bit0);
-	EightBit::Device::match(ACIA().CS0(), ADDRESS().word & EightBit::Chip::Bit15);
-	EightBit::Device::match(ACIA().CS1(), ADDRESS().word & EightBit::Chip::Bit13);
-	EightBit::Device::match(ACIA().CS2(), ADDRESS().word & EightBit::Chip::Bit14);
+	EightBit::Device::match(ACIA().RS(), ADDRESS().joined & EightBit::Chip::Bit0);
+	EightBit::Device::match(ACIA().CS0(), ADDRESS().joined & EightBit::Chip::Bit15);
+	EightBit::Device::match(ACIA().CS1(), ADDRESS().joined & EightBit::Chip::Bit13);
+	EightBit::Device::match(ACIA().CS2(), ADDRESS().joined & EightBit::Chip::Bit14);
 }
 
 bool Board::accessAcia() {
diff --git a/MC6809/test/Board.h b/MC6809/test/Board.h
index e29a238..e4c47ad 100644
--- a/MC6809/test/Board.h
+++ b/MC6809/test/Board.h
@@ -20,13 +20,13 @@ 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;
+	virtual void initialise() noexcept final;
 
 protected:
-	EightBit::MemoryMapping mapping(uint16_t address) final;
+	const EightBit::MemoryMapping& mapping(uint16_t address) noexcept final;
 
 private:
 	const Configuration& m_configuration;
@@ -35,6 +35,11 @@ private:
 	EightBit::Ram m_io = 0x2000;							// A000 - BFFF, 8K serial interface, minimally decoded
 	EightBit::Rom m_rom = 0x4000;							// C000 - FFFF, 16K ROM
 
+	EightBit::MemoryMapping m_ramMapping = { m_ram, 0x0000, EightBit::Chip::Mask16, EightBit::MemoryMapping::AccessLevel::ReadWrite };
+	EightBit::MemoryMapping m_unused2000Mapping = { m_unused2000, 0x8000, EightBit::Chip::Mask16, EightBit::MemoryMapping::AccessLevel::ReadOnly };
+	EightBit::MemoryMapping m_ioMapping = { m_io, 0xa000, EightBit::Chip::Mask16, EightBit::MemoryMapping::AccessLevel::ReadWrite };
+	EightBit::MemoryMapping m_romMapping = { m_rom, 0xc000, EightBit::Chip::Mask16, EightBit::MemoryMapping::AccessLevel::ReadOnly };
+
 	EightBit::mc6850 m_acia;
 
 	EightBit::mc6809 m_cpu = *this;
diff --git a/MC6809/unittest/Board.cpp b/MC6809/unittest/Board.cpp
index 70fa5b7..e248424 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();
@@ -16,12 +16,12 @@ void Board::raisePOWER() {
 	CPU().raiseHALT();
 }
 
-void Board::lowerPOWER() {
+void Board::lowerPOWER() noexcept {
 	CPU().lowerPOWER();
 	EightBit::Bus::lowerPOWER();
 }
 
-void Board::initialise() {
+void Board::initialise() noexcept {
 	CPU().ExecutingInstruction.connect([this](EightBit::mc6809& cpu) {
 		m_disassembleAt = CPU().PC();
 		m_ignoreDisassembly = m_disassembler.ignore();
@@ -33,6 +33,6 @@ void Board::initialise() {
 	});
 }
 
-EightBit::MemoryMapping Board::mapping(uint16_t) {
-	return { m_ram, 0x0000, 0xffff, EightBit::MemoryMapping::AccessLevel::ReadWrite };
+const EightBit::MemoryMapping& Board::mapping(uint16_t) noexcept {
+	return m_mapping;
 }
diff --git a/MC6809/unittest/Board.h b/MC6809/unittest/Board.h
index d01c7f2..055448b 100644
--- a/MC6809/unittest/Board.h
+++ b/MC6809/unittest/Board.h
@@ -11,16 +11,17 @@ public:
 
 	constexpr EightBit::mc6809& CPU() { return m_cpu; }
 
-	void raisePOWER() final;
-	void lowerPOWER() final;
+	void raisePOWER() noexcept final;
+	void lowerPOWER() noexcept final;
 
 protected:
-	void initialise() final;
+	void initialise() noexcept final;
 
-	EightBit::MemoryMapping mapping(uint16_t address) final;
+	const EightBit::MemoryMapping& mapping(uint16_t address) noexcept final;
 
 private:
 	EightBit::Ram m_ram = 0x10000;	// 0000 - FFFF, 64K RAM
+	EightBit::MemoryMapping m_mapping = { m_ram, 0x0000, 0xffff, EightBit::MemoryMapping::AccessLevel::ReadWrite };
 	EightBit::mc6809 m_cpu = { *this };
 	EightBit::Disassembly m_disassembler = { *this, m_cpu };
 
diff --git a/MC6809/unittest/mc6809_tests.cpp b/MC6809/unittest/mc6809_tests.cpp
index c916727..a57943d 100644
--- a/MC6809/unittest/mc6809_tests.cpp
+++ b/MC6809/unittest/mc6809_tests.cpp
@@ -4,1055 +4,1287 @@
 // Some tests from:
 // 6809 Assembly Language Programming, by Lance A. Leventhal
 // https://github.com/sorenroug/osnine-java/blob/master/core/cputests/
-// void setRegs(a, b, x, y, u)
 
-TEST_CASE("Add Accumulator B to Index Register X Unsigned", "[ABX]") {
+BOOST_AUTO_TEST_SUITE(ABX)
 
+BOOST_AUTO_TEST_CASE(Inherent) {
 	Board board;
 	board.raisePOWER();
 	auto& cpu = board.CPU();
 	auto cycles = cpu.step();	// Step over the reset
-
-    SECTION("Inherent") {
-		board.poke(0, 0x3a);
-		cpu.B() = 0x84;
-		cpu.X() = 0x1097;
-		cycles = cpu.step();
-		REQUIRE(cpu.X() == 0x111b);
-		REQUIRE(cycles == 3);
-    }
-
-    SECTION("Inherent test (ABX1)") {
-		cpu.A() = 0;
-		cpu.B() = 0xce;
-		cpu.X() = 0x8006;
-		cpu.Y() = 0;
-		cpu.U() = 0;
-		cpu.CC() = 0;
-		board.poke(0, 0x3a);
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0);
-		REQUIRE(cpu.B() == 0xce);
-		REQUIRE(cpu.X() == 0x80d4);
-		REQUIRE(cpu.Y() == 0);
-		REQUIRE(cpu.U() == 0);
-		REQUIRE(cpu.carry() == 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.negative() == 0);
-		REQUIRE(cpu.halfCarry() == 0);
-		REQUIRE(cycles == 3);
-    }
-
-    SECTION("Inherent test (ABX2)") {
-		cpu.A() = 0;
-		cpu.B() = 0xd6;
-		cpu.X() = 0x7ffe;
-		cpu.Y() = 0;
-		cpu.U() = 0;
-		cpu.CC() = EightBit::mc6809::CF | EightBit::mc6809::VF | EightBit::mc6809::ZF;
-		board.poke(0, 0x3a);
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0);
-		REQUIRE(cpu.B() == 0xd6);
-		REQUIRE(cpu.X() == 0x80d4);
-		REQUIRE(cpu.Y() == 0);
-		REQUIRE(cpu.U() == 0);
-		REQUIRE(cpu.carry() != 0);
-		REQUIRE(cpu.overflow() != 0);
-		REQUIRE(cpu.zero() != 0);
-		REQUIRE(cpu.negative() == 0);
-		REQUIRE(cpu.halfCarry() == 0);
-		REQUIRE(cycles == 3);
-    }
+	board.poke(0, 0x3a);
+	cpu.B() = 0x84;
+	cpu.X() = 0x1097;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.X(), 0x111b);
+	BOOST_CHECK_EQUAL(cycles, 3);
 }
 
-TEST_CASE("Add Memory Plus Carry to Accumulator", "[ADC][ADCA]") {
-
+BOOST_AUTO_TEST_CASE(ABX1) {
 	Board board;
 	board.raisePOWER();
 	auto& cpu = board.CPU();
 	auto cycles = cpu.step();	// Step over the reset
-
-    SECTION("Immediate (byte)") {
-		board.poke(0, 0x89);
-		board.poke(1, 0x7c);
-		cpu.CC() = EightBit::Chip::setBit(cpu.CC(), EightBit::mc6809::CF);
-		cpu.A() = 0x3a;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0xb7);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.halfCarry() != 0);
-		REQUIRE(cpu.overflow() != 0);
-		REQUIRE(cpu.negative() != 0);
-		REQUIRE(cpu.carry() == 0);
-		REQUIRE(cycles == 2);
-    }
-
-	SECTION("Immediate (byte) ADCANoC1") {
-		cpu.A() = 0x5;
-		cpu.CC() = 0;
-		board.poke(0, 0x89);
-		board.poke(1, 0x02);
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 7);
-		REQUIRE(cpu.carry() == 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.negative() == 0);
-		REQUIRE(cpu.halfCarry() == 0);
-		REQUIRE(cycles == 2);
-    }
-
-	/* Test half-carry $E + $2 = $10 */
-	SECTION("Immediate (byte) ADCANoC2") {
-		cpu.A() = 0xe;
-		cpu.CC() = 0;
-		board.poke(0, 0x89);
-		board.poke(1, 0x02);
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0x10);
-		REQUIRE(cpu.carry() == 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.negative() == 0);
-		REQUIRE(cpu.halfCarry() != 0);
-		REQUIRE(cycles == 2);
-    }
-
-	/* Add $22 and carry to register A ($14) */
-	SECTION("Immediate (byte) ADCAWiC") {
-		cpu.A() = 0x14;
-		cpu.CC() = EightBit::mc6809::CF | EightBit::mc6809::HF;
-		board.poke(0, 0x89);
-		board.poke(1, 0x22);
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0x37);
-		REQUIRE(cpu.carry() == 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.negative() == 0);
-		REQUIRE(cpu.halfCarry() == 0);
-		REQUIRE(cycles == 2);
-    }
-
-	/* Test that half-carry is set when adding with a carry */
-	SECTION("Immediate (byte) ADCAWiHC") {
-		cpu.A() = 0x14;
-		cpu.CC() = EightBit::mc6809::CF;
-		board.poke(0, 0x89);
-		board.poke(1, 0x2B);
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0x40);
-		REQUIRE(cpu.carry() == 0);
-		REQUIRE(cpu.halfCarry() != 0);
-		REQUIRE(cycles == 2);
-    }
+	cpu.A() = 0;
+	cpu.B() = 0xce;
+	cpu.X() = 0x8006;
+	cpu.Y() = 0;
+	cpu.U() = 0;
+	cpu.CC() = 0;
+	board.poke(0, 0x3a);
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0);
+	BOOST_CHECK_EQUAL(cpu.B(), 0xce);
+	BOOST_CHECK_EQUAL(cpu.X(), 0x80d4);
+	BOOST_CHECK_EQUAL(cpu.Y(), 0);
+	BOOST_CHECK_EQUAL(cpu.U(), 0);
+	BOOST_CHECK_EQUAL(cpu.carry(), 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK_EQUAL(cpu.negative(), 0);
+	BOOST_CHECK_EQUAL(cpu.halfCarry(), 0);
+	BOOST_CHECK_EQUAL(cycles, 3);
 }
 
-TEST_CASE("Add Memory to Accumulator", "[ADD][ADDA][ADDB][ADDD]") {
-
+BOOST_AUTO_TEST_CASE(ABX2) {
 	Board board;
 	board.raisePOWER();
 	auto& cpu = board.CPU();
 	auto cycles = cpu.step();	// Step over the reset
-
-    SECTION("Immediate (byte)") {
-		board.poke(0, 0x8b);
-		board.poke(1, 0x8b);
-		cpu.A() = 0x24;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0xaf);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.halfCarry() == 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.negative() != 0);
-		REQUIRE(cpu.carry() == 0);
-		REQUIRE(cycles == 2);
-    }
-
-	// Add 0x02 to A=0x04.
-	SECTION("Immediate (byte) (ADDANoC)") {
-		board.poke(0, 0x8b);
-		board.poke(1, 0x02);
-		cpu.CC() = 0;
-		cpu.A() = 4;
-		cpu.B() = 5;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 6);
-		REQUIRE(cpu.B() == 5);
-		REQUIRE(cpu.halfCarry() == 0);
-		REQUIRE(cpu.negative() == 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.carry() == 0);
-		REQUIRE(cycles == 2);
-    }
-
-	// The overflow (V) bit indicates signed two’s complement overflow, which occurs when the
-	// sign bit differs from the carry bit after an arithmetic operation.
-	// A=0x03 + 0xFF becomes 0x02
-	SECTION("Immediate (byte) (ADDAWiC)") {
-		board.poke(0, 0x8b);
-		board.poke(1, 0xff);
-		cpu.CC() = 0;
-		cpu.A() = 3;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 2);
-		REQUIRE(cpu.negative() == 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.carry() != 0);
-		REQUIRE(cycles == 2);
-    }
-
-	// positive + positive with overflow.
-	// B=0x40 + 0x41 becomes 0x81 or -127
-    SECTION("Immediate (byte) ADDB1") {
-		board.poke(0, 0xcb);
-		board.poke(1, 0x41);
-		cpu.B() = 0x40;
-		cpu.CC() = 0;
-		cycles = cpu.step();
-		REQUIRE(cpu.B() == 0x81);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.halfCarry() == 0);
-		REQUIRE(cpu.overflow() != 0);
-		REQUIRE(cpu.negative() != 0);
-		REQUIRE(cpu.carry() == 0);
-		REQUIRE(cycles == 2);
-    }
-
-	// negative + negative.
-	// B=0xFF + 0xFF becomes 0xFE or -2
-    SECTION("Immediate (byte) ADDB2") {
-		board.poke(0, 0xcb);
-		board.poke(1, 0xff);
-		cpu.B() = 0xff;
-		cpu.CC() = 0;
-		cycles = cpu.step();
-		REQUIRE(cpu.B() == 0xfe);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.negative() != 0);
-		REQUIRE(cpu.carry() != 0);
-		REQUIRE(cycles == 2);
-    }
-
-	// negative + negative with overflow.
-	// B=0xC0 + 0xBF becomes 0x7F or 127
-    SECTION("Immediate (byte) ADDB3") {
-		board.poke(0, 0xcb);
-		board.poke(1, 0xbf);
-		cpu.B() = 0xc0;
-		cpu.CC() = 0;
-		cycles = cpu.step();
-		REQUIRE(cpu.B() == 0x7f);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.overflow() != 0);
-		REQUIRE(cpu.negative() == 0);
-		REQUIRE(cpu.carry() != 0);
-		REQUIRE(cycles == 2);
-    }
-
-	// positive + negative with negative result.
-	// B=0x02 + 0xFC becomes 0xFE or -2
-    SECTION("Immediate (byte) ADDB4") {
-		board.poke(0, 0xcb);
-		board.poke(1, 0xfc);
-		cpu.B() = 0x02;
-		cpu.CC() = 0;
-		cycles = cpu.step();
-		REQUIRE(cpu.B() == 0xfe);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.negative() != 0);
-		REQUIRE(cpu.carry() == 0);
-		REQUIRE(cycles == 2);
-    }
-
-	// Add 0x02B0 to D=0x0405 becomes 0x6B5.
-	// positive + positive = positive
-	SECTION("Immediate (word) (ADDDNoC)") {
-		board.poke(0, 0xc3);
-		board.poke(1, 0x02);
-		board.poke(2, 0xb0);
-		cpu.CC() = 0;
-		cpu.A() = 4;
-		cpu.B() = 5;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0x06);
-		REQUIRE(cpu.B() == 0xb5);
-		REQUIRE(cpu.negative() == 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.carry() == 0);
-		REQUIRE(cycles == 4);
-    }
-
-	// Add 0xE2B0 to D=0x8405 becomes 0x66B5.
-	// negative + negative = positive + overflow
-	SECTION("Immediate (word) (ADDD1)") {
-		board.poke(0, 0xc3);
-		board.poke(1, 0xe2);
-		board.poke(2, 0xb0);
-		cpu.CC() = 0;
-		cpu.A() = 0x84;
-		cpu.B() = 5;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0x66);
-		REQUIRE(cpu.B() == 0xb5);
-		REQUIRE(cpu.negative() == 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.overflow() != 0);
-		REQUIRE(cpu.carry() != 0);
-		REQUIRE(cycles == 4);
-    }
-
-	// negative + negative = negative.
-	// Add 0xE000 to D=0xD000 becomes 0xB000
-	SECTION("Immediate (word) (ADDD2)") {
-		board.poke(0, 0xc3);
-		board.poke(1, 0xe0);
-		board.poke(2, 0);
-		cpu.CC() = 0;
-		cpu.A() = 0xd0;
-		cpu.B() = 0;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0xb0);
-		REQUIRE(cpu.B() == 0x00);
-		REQUIRE(cpu.negative() != 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.carry() != 0);
-		REQUIRE(cpu.cycles() == 4);
-    }
-
-	// positive + positive = negative + overflow.
-	// Add 0x7000 to D=0x7000 becomes 0xE000
-	SECTION("Immediate (word) (ADDD3)") {
-		board.poke(0, 0xc3);
-		board.poke(1, 0x70);
-		board.poke(2, 0);
-		cpu.CC() = 0;
-		cpu.A() = 0x70;
-		cpu.B() = 0;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0xe0);
-		REQUIRE(cpu.B() == 0x00);
-		REQUIRE(cpu.negative() != 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.overflow() != 0);
-		REQUIRE(cpu.carry() == 0);
-		REQUIRE(cpu.cycles() == 4);
-    }
+	cpu.A() = 0;
+	cpu.B() = 0xd6;
+	cpu.X() = 0x7ffe;
+	cpu.Y() = 0;
+	cpu.U() = 0;
+	cpu.CC() = EightBit::mc6809::CF | EightBit::mc6809::VF | EightBit::mc6809::ZF;
+	board.poke(0, 0x3a);
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0);
+	BOOST_CHECK_EQUAL(cpu.B(), 0xd6);
+	BOOST_CHECK_EQUAL(cpu.X(), 0x80d4);
+	BOOST_CHECK_EQUAL(cpu.Y(), 0);
+	BOOST_CHECK_EQUAL(cpu.U(), 0);
+	BOOST_CHECK(cpu.carry() != 0);
+	BOOST_CHECK(cpu.overflow() != 0);
+	BOOST_CHECK(cpu.zero() != 0);
+	BOOST_CHECK_EQUAL(cpu.negative(), 0);
+	BOOST_CHECK_EQUAL(cpu.halfCarry(), 0);
+	BOOST_CHECK_EQUAL(cycles, 3);
 }
 
-TEST_CASE("Logical AND Accumulator", "[AND][ANDA]") {
+BOOST_AUTO_TEST_SUITE_END()
 
+//
+
+BOOST_AUTO_TEST_SUITE(ADC)
+
+BOOST_AUTO_TEST_CASE(Immediate_byte) {
 	Board board;
 	board.raisePOWER();
 	auto& cpu = board.CPU();
 	auto cycles = cpu.step();	// Step over the reset
-
-    SECTION("Immediate (byte)") {
-		board.poke(0, 0x84);
-		board.poke(1, 0x13);
-		cpu.A() = 0xfc;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0x10);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.negative() == 0);
-		REQUIRE(cycles == 2);
-    }
+	board.poke(0, 0x89);
+	board.poke(1, 0x7c);
+	cpu.CC() = EightBit::Chip::setBit(cpu.CC(), EightBit::mc6809::CF);
+	cpu.A() = 0x3a;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0xb7);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK(cpu.halfCarry() != 0);
+	BOOST_CHECK(cpu.overflow() != 0);
+	BOOST_CHECK(cpu.negative() != 0);
+	BOOST_CHECK_EQUAL(cpu.carry(), 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
 }
 
-TEST_CASE("Shift Accumulator or Memory Byte Left", "[ASL][ASLA]") {
-
+BOOST_AUTO_TEST_CASE(ADCANoC1) {
 	Board board;
 	board.raisePOWER();
 	auto& cpu = board.CPU();
 	auto cycles = cpu.step();	// Step over the reset
-
-    SECTION("Inherent") {
-		board.poke(0, 0x48);
-		cpu.A() = 0x7a;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0xf4);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.overflow() != 0);
-		REQUIRE(cpu.negative() != 0);
-		REQUIRE(cycles == 2);
-    }
+	cpu.A() = 0x5;
+	cpu.CC() = 0;
+	board.poke(0, 0x89);
+	board.poke(1, 0x02);
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 7);
+	BOOST_CHECK_EQUAL(cpu.carry(), 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK_EQUAL(cpu.negative(), 0);
+	BOOST_CHECK_EQUAL(cpu.halfCarry(), 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
 }
 
-TEST_CASE("Shift Accumulator or Memory Byte Right", "[ASR][ASRA]") {
-
+// Test half-carry $E + $2 = $10
+BOOST_AUTO_TEST_CASE(ADCANoC2) {
 	Board board;
 	board.raisePOWER();
 	auto& cpu = board.CPU();
 	auto cycles = cpu.step();	// Step over the reset
-
-    SECTION("Inherent") {
-		board.poke(0, 0x47);
-		cpu.A() = 0xcb;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0xe5);
-		REQUIRE(cpu.carry() != 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.negative() != 0);
-		REQUIRE(cycles == 2);
-    }
+	cpu.A() = 0xe;
+	cpu.CC() = 0;
+	board.poke(0, 0x89);
+	board.poke(1, 0x02);
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0x10);
+	BOOST_CHECK_EQUAL(cpu.carry(), 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK_EQUAL(cpu.negative(), 0);
+	BOOST_CHECK(cpu.halfCarry() != 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
 }
 
-TEST_CASE("Bit Test", "[BIT][BITA]") {
-
+// Add $22 and carry to register A ($14)
+BOOST_AUTO_TEST_CASE(ADCAWiC) {
 	Board board;
 	board.raisePOWER();
 	auto& cpu = board.CPU();
 	auto cycles = cpu.step();	// Step over the reset
-
-    SECTION("Immediate (byte)") {
-		board.poke(0, 0x85);
-		board.poke(1, 0xe0);
-		cpu.A() = 0xa6;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0xa6);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.negative() != 0);
-		REQUIRE(cycles == 2);
-    }
+	cpu.A() = 0x14;
+	cpu.CC() = EightBit::mc6809::CF | EightBit::mc6809::HF;
+	board.poke(0, 0x89);
+	board.poke(1, 0x22);
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0x37);
+	BOOST_CHECK_EQUAL(cpu.carry(), 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK_EQUAL(cpu.negative(), 0);
+	BOOST_CHECK_EQUAL(cpu.halfCarry(), 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
 }
 
-TEST_CASE("Clear Accumulator or Memory", "[CLR][CLRA]") {
-
+// Test that half-carry is set when adding with a carry
+BOOST_AUTO_TEST_CASE(ADCAWiHC) {
 	Board board;
 	board.raisePOWER();
 	auto& cpu = board.CPU();
 	auto cycles = cpu.step();	// Step over the reset
-
-    SECTION("Implied") {
-		board.poke(0, 0x4f);
-		cpu.A() = 0x43;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0x00);
-		REQUIRE(cpu.carry() == 0);
-		REQUIRE(cpu.zero() != 0);
-		REQUIRE(cpu.negative() == 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cycles == 2);
-    }
+	cpu.A() = 0x14;
+	cpu.CC() = EightBit::mc6809::CF;
+	board.poke(0, 0x89);
+	board.poke(1, 0x2B);
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0x40);
+	BOOST_CHECK_EQUAL(cpu.carry(), 0);
+	BOOST_CHECK(cpu.halfCarry() != 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
 }
 
-TEST_CASE("Compare Memory with a Register", "[CMP][CMPA][CMPB][CMPX]") {
+BOOST_AUTO_TEST_SUITE_END()
 
+//
+
+BOOST_AUTO_TEST_SUITE(ADD)
+
+BOOST_AUTO_TEST_CASE(Immediate_byte) {
 	Board board;
 	board.raisePOWER();
 	auto& cpu = board.CPU();
 	auto cycles = cpu.step();	// Step over the reset
-
-	SECTION("Immediate (byte)") {
-		board.poke(0, 0x81);
-		board.poke(1, 0x18);
-		cpu.A() = 0xf6;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0xf6);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.negative() != 0);
-		REQUIRE(cpu.carry() == 0);
-		REQUIRE(cycles == 2);
-	}
-
-	SECTION("Indirect mode: CMPA ,Y+ (CMP1)") {
-		board.poke(0, 0xa1);
-		board.poke(1, 0xa0);
-		board.poke(0x205, 0xff);
-		cpu.CC() = 0;
-		cpu.A() = 0xff;
-		cpu.B() = 0;
-		cpu.X() = 0;
-		cpu.Y() = 0x205;
-		cpu.U() = 0;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0xff);
-		REQUIRE(cpu.B() == 0x00);
-		REQUIRE(cpu.X() == 0x00);
-		REQUIRE(cpu.Y() == 0x206);
-		REQUIRE(cpu.U() == 0);
-		REQUIRE(cpu.zero() != 0);
-		REQUIRE(cycles == 6);
-	}
-
-	// B = 0xA0, CMPB with 0xA0
-    SECTION("Immediate (CMP2)") {
-		board.poke(0, 0xc1);
-		board.poke(1, 0xa0);
-		cpu.CC() = EightBit::mc6809::NF;
-		cpu.B() = 0xa0;
-		cycles = cpu.step();
-		REQUIRE(cpu.negative() == 0);
-		REQUIRE(cpu.zero() != 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.carry() == 0);
-		REQUIRE(cycles == 2);
-    }
-
-	// B = 0x70, CMPB with 0xA0
-    SECTION("Immediate (CMP3)") {
-		board.poke(0, 0xc1);
-		board.poke(1, 0xa0);
-		cpu.CC() = EightBit::mc6809::NF;
-		cpu.B() = 0x70;
-		cycles = cpu.step();
-		REQUIRE(cpu.carry() != 0);
-		REQUIRE(cpu.overflow() != 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.negative() != 0);
-		REQUIRE(cycles == 2);
-    }
-
-	// Compare 0x5410 with 0x5410
-    SECTION("Immediate (word) (CMP16)") {
-		board.poke(0, 0xc1);
-		board.poke(1, 0xa0);
-		cpu.CC() = EightBit::mc6809::NF;
-		cpu.B() = 0x70;
-		cycles = cpu.step();
-		REQUIRE(cpu.carry() != 0);
-		REQUIRE(cpu.overflow() != 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.negative() != 0);
-		REQUIRE(cycles == 2);
-    }
-
-    SECTION("Immediate (word)") {
-		board.poke(0, 0x8c);
-		board.poke(1, 0x1b);
-		board.poke(2, 0xb0);
-		cpu.X() = 0x1ab0;
-		cycles = cpu.step();
-		REQUIRE(cpu.X() == 0x1ab0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.negative() != 0);
-		REQUIRE(cpu.carry() != 0);
-		REQUIRE(cycles == 4);
-    }
+	board.poke(0, 0x8b);
+	board.poke(1, 0x8b);
+	cpu.A() = 0x24;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0xaf);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK_EQUAL(cpu.halfCarry(), 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK(cpu.negative() != 0);
+	BOOST_CHECK_EQUAL(cpu.carry(), 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
 }
 
-TEST_CASE("Decrement Accumulator or Memory", "[DEC][DECA]") {
-
+// Add 0x02 to A=0x04.
+BOOST_AUTO_TEST_CASE(ADDANoC) {
 	Board board;
 	board.raisePOWER();
 	auto& cpu = board.CPU();
 	auto cycles = cpu.step();	// Step over the reset
-
-    SECTION("Inherent (DECA0x32)") {
-		board.poke(0, 0x4a);
-		cpu.CC() = 0;
-		cpu.A() = 0x32;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0x31);
-		REQUIRE(cpu.carry() == 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.negative() == 0);
-		REQUIRE(cycles == 2);
-    }
-
-	// Test 0x80 - special case
-    SECTION("Inherent (DECA0x80)") {
-		board.poke(0, 0x4a);
-		cpu.CC() = 0;
-		cpu.A() = 0x80;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0x7f);
-		REQUIRE(cpu.carry() == 0);
-		REQUIRE(cpu.overflow() != 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.negative() == 0);
-		REQUIRE(cycles == 2);
-    }
-
-	// Test 0x00 - special case
-    SECTION("Inherent (DECA0x00)") {
-		board.poke(0, 0x4a);
-		cpu.CC() = 0;
-		cpu.A() = 0x00;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0xff);
-		REQUIRE(cpu.carry() == 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.negative() != 0);
-		REQUIRE(cycles == 2);
-    }
+	board.poke(0, 0x8b);
+	board.poke(1, 0x02);
+	cpu.CC() = 0;
+	cpu.A() = 4;
+	cpu.B() = 5;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 6);
+	BOOST_CHECK_EQUAL(cpu.B(), 5);
+	BOOST_CHECK_EQUAL(cpu.halfCarry(), 0);
+	BOOST_CHECK_EQUAL(cpu.negative(), 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK_EQUAL(cpu.carry(), 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
 }
 
-TEST_CASE("Increment Accumulator or Memory Location by 1", "[INC][INCA]") {
-
+// A=0x03 + 0xFF becomes 0x02
+BOOST_AUTO_TEST_CASE(ADDAWiC) {
 	Board board;
 	board.raisePOWER();
 	auto& cpu = board.CPU();
 	auto cycles = cpu.step();	// Step over the reset
-
-    SECTION("Inherent (INCA1)") {
-		board.poke(0, 0x4c);
-		cpu.CC() = 0;
-		cpu.A() = 0x32;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0x33);
-		REQUIRE(cpu.negative() == 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.carry() == 0);
-		REQUIRE(cycles == 2);
-    }
-
-    SECTION("Inherent (INCA2)") {
-		board.poke(0, 0x4c);
-		cpu.CC() = 0;
-		cpu.A() = 0x7f;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0x80);
-		REQUIRE(cpu.negative() != 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.overflow() != 0);
-		REQUIRE(cpu.carry() == 0);
-		REQUIRE(cycles == 2);
-    }
-
-    SECTION("Inherent (INCA3)") {
-		board.poke(0, 0x4c);
-		cpu.CC() = 0;
-		cpu.A() = 0xff;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0);
-		REQUIRE(cpu.negative() == 0);
-		REQUIRE(cpu.zero() != 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.carry() == 0);
-		REQUIRE(cycles == 2);
-    }
+	board.poke(0, 0x8b);
+	board.poke(1, 0xff);
+	cpu.CC() = 0;
+	cpu.A() = 3;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 2);
+	BOOST_CHECK_EQUAL(cpu.negative(), 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK(cpu.carry() != 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
 }
 
-TEST_CASE("Subtract Memory from Accumulator with Borrow (8-bit)", "[SBC][SBCA][SBCB]") {
-
+// positive + positive with overflow: B=0x40 + 0x41 becomes 0x81
+BOOST_AUTO_TEST_CASE(ADDB1) {
 	Board board;
 	board.raisePOWER();
 	auto& cpu = board.CPU();
 	auto cycles = cpu.step();	// Step over the reset
-
-    SECTION("Immediate (byte)") {
-		board.poke(0, 0x82);
-		board.poke(1, 0x34);
-		cpu.A() = 0x14;
-		cpu.CC() = cpu.setBit(cpu.CC(), EightBit::mc6809::CF);
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0xdf);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.negative() != 0);
-		REQUIRE(cpu.carry() != 0);
-		REQUIRE(cycles == 2);
-    }
-
-	// Test the subtraction with carry instruction.
-	// B=0x35 - addr(0x503)=0x3 - C=1 becomes 0x31
-	// SBCB dp+03
-    SECTION("Direct (SBCB)") {
-		board.poke(0, 0xd2);
-		board.poke(1, 0x03);
-		board.poke(0x503, 0x03);
-		cpu.DP() = 5;
-		cpu.B() = 0x35;
-		cpu.CC() = EightBit::mc6809::CF;
-		cycles = cpu.step();
-		REQUIRE(cpu.B() == 0x31);
-		REQUIRE(cpu.carry() == 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.negative() == 0);
-		REQUIRE(cycles == 4);
-    }
-
-	// Test the SBCA instruction.
-	// A=0xFF - 0xFE - C=1 becomes 0x00
-    SECTION("Immediate (SBCA) (SBCA1)") {
-		board.poke(0, 0x82);
-		board.poke(1, 0xfe);
-		board.poke(0x503, 0x03);
-		cpu.CC() = EightBit::mc6809::CF | EightBit::mc6809::NF;
-		cpu.A() = 0xff;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0);
-		REQUIRE(cpu.carry() == 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.zero() != 0);
-		REQUIRE(cpu.negative() == 0);
-		REQUIRE(cycles == 2);
-    }
-
-	// Test the SBCA instruction.
-	// A=0x00 - 0xFF - C=0 becomes 0x01
-    SECTION("Immediate (SBCA) (SBCA2)") {
-		board.poke(0, 0x82);
-		board.poke(1, 0xff);
-		cpu.CC() = EightBit::mc6809::NF | EightBit::mc6809::VF;
-		cpu.A() = 0;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 1);
-		REQUIRE(cpu.carry() != 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.negative() == 0);
-		REQUIRE(cycles == 2);
-    }
-
-	// Test the SBCA instruction.
-	// A=0x00 - 0x01 - C=0 becomes 0xFF
-    SECTION("Immediate (SBCA) (SBCA3)") {
-		board.poke(0, 0x82);
-		board.poke(1, 0x01);
-		cpu.CC() = EightBit::mc6809::NF | EightBit::mc6809::VF;
-		cpu.A() = 0;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0xff);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.negative() != 0);
-		REQUIRE(cycles == 2);
-    }
+	board.poke(0, 0xcb);
+	board.poke(1, 0x41);
+	cpu.B() = 0x40;
+	cpu.CC() = 0;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.B(), 0x81);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK_EQUAL(cpu.halfCarry(), 0);
+	BOOST_CHECK(cpu.overflow() != 0);
+	BOOST_CHECK(cpu.negative() != 0);
+	BOOST_CHECK_EQUAL(cpu.carry(), 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
 }
 
-TEST_CASE("Subtract Memory from Register", "[SUB][SUBA]") {
-
+// negative + negative: B=0xFF + 0xFF becomes 0xFE
+BOOST_AUTO_TEST_CASE(ADDB2) {
 	Board board;
 	board.raisePOWER();
 	auto& cpu = board.CPU();
 	auto cycles = cpu.step();	// Step over the reset
-
-	// Test the SUBA instruction.
-	// The overflow (V) bit indicates signed two’s complement overflow, which
-	// occurs when the sign bit differs from the carry bit after an arithmetic
-	// operation.
-	// A=0x00 - 0xFF becomes 0x01
-	// positive - negative = positive
-	SECTION("Immediate (SUBA) (SUBA1)") {
-		board.poke(0, 0x80);
-		board.poke(1, 0xff);
-		cpu.CC() = EightBit::mc6809::CF | EightBit::mc6809::NF | EightBit::mc6809::VF;
-		cpu.A() = 0;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 1);
-		REQUIRE(cpu.carry() != 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.negative() == 0);
-		REQUIRE(cycles == 2);
-    }
-
-	// A=0x00 - 0x01 becomes 0xFF
-	// positive - positive = negative
-	SECTION("Immediate (SUBA) (SUBA2)") {
-		board.poke(0, 0x80);
-		board.poke(1, 1);
-		cpu.CC() = EightBit::mc6809::CF | EightBit::mc6809::NF | EightBit::mc6809::VF;
-		cpu.A() = 0;
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 0xff);
-		REQUIRE(cpu.negative() != 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.carry() != 0);
-		REQUIRE(cycles == 2);
-    }
-
-	// Test the subtraction instruction.
-	// IMMEDIATE mode:   B=0x02 - 0xB3  becomes 0x4F
-	// positive - negative = positive
-	SECTION("Immediate (SUBB) (SUBB1)") {
-		board.poke(0, 0xc0);
-		board.poke(1, 0xb3);
-		cpu.CC() = 0;
-		cpu.B() = 2;
-		cycles = cpu.step();
-		REQUIRE(cpu.B() == 0x4f);
-		REQUIRE(cpu.negative() == 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.carry() != 0);
-		REQUIRE(cycles == 2);
-    }
-
-	// Test the subtraction instruction.
-	// IMMEDIATE mode:   B=0x02 - 0x81  becomes 0x81
-	// positive - negative = negative + overflow
-	SECTION("Immediate (SUBB) (SUBB2)") {
-		board.poke(0, 0xc0);
-		board.poke(1, 0x81);
-		cpu.CC() = 0;
-		cpu.B() = 2;
-		cycles = cpu.step();
-		REQUIRE(cpu.B() == 0x81);
-		REQUIRE(cpu.negative() != 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.overflow() != 0);
-		REQUIRE(cpu.carry() != 0);
-		REQUIRE(cycles == 2);
-    }
-
-	// Example from Programming the 6809.
-	// 0x03 - 0x21 = 0xE2
-	// positive - positive = negative
-	SECTION("Immediate (SUBB) (SUBBY)") {
-		board.poke(0, 0xe0);
-		board.poke(1, 0xa4);
-		board.poke(0x21, 0x21);
-		cpu.CC() = EightBit::mc6809::ZF;
-		cpu.B() = 3;
-		cpu.Y() = 0x21;
-		cycles = cpu.step();
-		REQUIRE(cpu.B() == 0xe2);
-		REQUIRE(cpu.negative() != 0);
-		REQUIRE(cpu.zero() == 0);
-		REQUIRE(cpu.overflow() == 0);
-		REQUIRE(cpu.carry() != 0);
-		REQUIRE(cycles == 4);
-    }
+	board.poke(0, 0xcb);
+	board.poke(1, 0xff);
+	cpu.B() = 0xff;
+	cpu.CC() = 0;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.B(), 0xfe);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK(cpu.negative() != 0);
+	BOOST_CHECK(cpu.carry() != 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
 }
 
-TEST_CASE(" Branch if Greater Than Zero", "[BGT]") {
-
+// negative + negative with overflow: B=0xC0 + 0xBF becomes 0x7F
+BOOST_AUTO_TEST_CASE(ADDB3) {
 	Board board;
 	board.raisePOWER();
 	auto& cpu = board.CPU();
 	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0xcb);
+	board.poke(1, 0xbf);
+	cpu.B() = 0xc0;
+	cpu.CC() = 0;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.B(), 0x7f);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK(cpu.overflow() != 0);
+	BOOST_CHECK_EQUAL(cpu.negative(), 0);
+	BOOST_CHECK(cpu.carry() != 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
 
+// positive + negative with negative result: B=0x02 + 0xFC becomes 0xFE
+BOOST_AUTO_TEST_CASE(ADDB4) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0xcb);
+	board.poke(1, 0xfc);
+	cpu.B() = 0x02;
+	cpu.CC() = 0;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.B(), 0xfe);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK(cpu.negative() != 0);
+	BOOST_CHECK_EQUAL(cpu.carry(), 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
+
+// Add 0x02B0 to D=0x0405 becomes 0x6B5
+BOOST_AUTO_TEST_CASE(ADDDNoC) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0xc3);
+	board.poke(1, 0x02);
+	board.poke(2, 0xb0);
+	cpu.CC() = 0;
+	cpu.A() = 4;
+	cpu.B() = 5;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0x06);
+	BOOST_CHECK_EQUAL(cpu.B(), 0xb5);
+	BOOST_CHECK_EQUAL(cpu.negative(), 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK_EQUAL(cpu.carry(), 0);
+	BOOST_CHECK_EQUAL(cycles, 4);
+}
+
+// Add 0xE2B0 to D=0x8405 becomes 0x66B5
+BOOST_AUTO_TEST_CASE(ADDD1) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0xc3);
+	board.poke(1, 0xe2);
+	board.poke(2, 0xb0);
+	cpu.CC() = 0;
+	cpu.A() = 0x84;
+	cpu.B() = 5;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0x66);
+	BOOST_CHECK_EQUAL(cpu.B(), 0xb5);
+	BOOST_CHECK_EQUAL(cpu.negative(), 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK(cpu.overflow() != 0);
+	BOOST_CHECK(cpu.carry() != 0);
+	BOOST_CHECK_EQUAL(cycles, 4);
+}
+
+// Add 0xE000 to D=0xD000 becomes 0xB000
+BOOST_AUTO_TEST_CASE(ADDD2) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0xc3);
+	board.poke(1, 0xe0);
+	board.poke(2, 0);
+	cpu.CC() = 0;
+	cpu.A() = 0xd0;
+	cpu.B() = 0;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0xb0);
+	BOOST_CHECK_EQUAL(cpu.B(), 0x00);
+	BOOST_CHECK(cpu.negative() != 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK(cpu.carry() != 0);
+	BOOST_CHECK_EQUAL(cpu.cycles(), 4);
+}
+
+// Add 0x7000 to D=0x7000 becomes 0xE000
+BOOST_AUTO_TEST_CASE(ADDD3) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0xc3);
+	board.poke(1, 0x70);
+	board.poke(2, 0);
+	cpu.CC() = 0;
+	cpu.A() = 0x70;
+	cpu.B() = 0;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0xe0);
+	BOOST_CHECK_EQUAL(cpu.B(), 0x00);
+	BOOST_CHECK(cpu.negative() != 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK(cpu.overflow() != 0);
+	BOOST_CHECK_EQUAL(cpu.carry(), 0);
+	BOOST_CHECK_EQUAL(cpu.cycles(), 4);
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+//
+
+BOOST_AUTO_TEST_SUITE(AND_Accumulator)
+
+BOOST_AUTO_TEST_CASE(Immediate_byte) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x84);
+	board.poke(1, 0x13);
+	cpu.A() = 0xfc;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0x10);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK_EQUAL(cpu.negative(), 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+//
+
+BOOST_AUTO_TEST_SUITE(ASL)
+
+BOOST_AUTO_TEST_CASE(Inherent) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x48);
+	cpu.A() = 0x7a;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0xf4);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK(cpu.overflow() != 0);
+	BOOST_CHECK(cpu.negative() != 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+//
+
+BOOST_AUTO_TEST_SUITE(ASR)
+
+BOOST_AUTO_TEST_CASE(Inherent) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x47);
+	cpu.A() = 0xcb;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0xe5);
+	BOOST_CHECK(cpu.carry() != 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK(cpu.negative() != 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+//
+
+BOOST_AUTO_TEST_SUITE(BIT_Test)
+
+BOOST_AUTO_TEST_CASE(Immediate_byte) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x85);
+	board.poke(1, 0xe0);
+	cpu.A() = 0xa6;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0xa6);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK(cpu.negative() != 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+//
+
+BOOST_AUTO_TEST_SUITE(CLR)
+
+BOOST_AUTO_TEST_CASE(Implied) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x4f);
+	cpu.A() = 0x43;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0x00);
+	BOOST_CHECK_EQUAL(cpu.carry(), 0);
+	BOOST_CHECK(cpu.zero() != 0);
+	BOOST_CHECK_EQUAL(cpu.negative(), 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+//
+
+BOOST_AUTO_TEST_SUITE(CMP)
+
+BOOST_AUTO_TEST_CASE(Immediate_byte) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x81);
+	board.poke(1, 0x18);
+	cpu.A() = 0xf6;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0xf6);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK(cpu.negative() != 0);
+	BOOST_CHECK_EQUAL(cpu.carry(), 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
+
+BOOST_AUTO_TEST_CASE(CMP1_indexed) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0xa1);
+	board.poke(1, 0xa0);
+	board.poke(0x205, 0xff);
+	cpu.CC() = 0;
+	cpu.A() = 0xff;
+	cpu.B() = 0;
+	cpu.X() = 0;
+	cpu.Y() = 0x205;
+	cpu.U() = 0;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0xff);
+	BOOST_CHECK_EQUAL(cpu.B(), 0x00);
+	BOOST_CHECK_EQUAL(cpu.X(), 0x00);
+	BOOST_CHECK_EQUAL(cpu.Y(), 0x206);
+	BOOST_CHECK_EQUAL(cpu.U(), 0);
+	BOOST_CHECK(cpu.zero() != 0);
+	BOOST_CHECK_EQUAL(cycles, 6);
+}
+
+// B = 0xA0, CMPB with 0xA0
+BOOST_AUTO_TEST_CASE(CMP2) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0xc1);
+	board.poke(1, 0xa0);
+	cpu.CC() = EightBit::mc6809::NF;
+	cpu.B() = 0xa0;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.negative(), 0);
+	BOOST_CHECK(cpu.zero() != 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK_EQUAL(cpu.carry(), 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
+
+// B = 0x70, CMPB with 0xA0
+BOOST_AUTO_TEST_CASE(CMP3) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0xc1);
+	board.poke(1, 0xa0);
+	cpu.CC() = EightBit::mc6809::NF;
+	cpu.B() = 0x70;
+	cycles = cpu.step();
+	BOOST_CHECK(cpu.carry() != 0);
+	BOOST_CHECK(cpu.overflow() != 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK(cpu.negative() != 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
+
+// Compare 0x5410 with 0x5410
+BOOST_AUTO_TEST_CASE(CMP16) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0xc1);
+	board.poke(1, 0xa0);
+	cpu.CC() = EightBit::mc6809::NF;
+	cpu.B() = 0x70;
+	cycles = cpu.step();
+	BOOST_CHECK(cpu.carry() != 0);
+	BOOST_CHECK(cpu.overflow() != 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK(cpu.negative() != 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
+
+BOOST_AUTO_TEST_CASE(Immediate_word) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x8c);
+	board.poke(1, 0x1b);
+	board.poke(2, 0xb0);
+	cpu.X() = 0x1ab0;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.X(), 0x1ab0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK(cpu.negative() != 0);
+	BOOST_CHECK(cpu.carry() != 0);
+	BOOST_CHECK_EQUAL(cycles, 4);
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+//
+
+BOOST_AUTO_TEST_SUITE(DEC)
+
+BOOST_AUTO_TEST_CASE(DECA0x32) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x4a);
+	cpu.CC() = 0;
+	cpu.A() = 0x32;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0x31);
+	BOOST_CHECK_EQUAL(cpu.carry(), 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK_EQUAL(cpu.negative(), 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
+
+// Test 0x80 - special case
+BOOST_AUTO_TEST_CASE(DECA0x80) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x4a);
+	cpu.CC() = 0;
+	cpu.A() = 0x80;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0x7f);
+	BOOST_CHECK_EQUAL(cpu.carry(), 0);
+	BOOST_CHECK(cpu.overflow() != 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK_EQUAL(cpu.negative(), 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
+
+// Test 0x00 - special case
+BOOST_AUTO_TEST_CASE(DECA0x00) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x4a);
+	cpu.CC() = 0;
+	cpu.A() = 0x00;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0xff);
+	BOOST_CHECK_EQUAL(cpu.carry(), 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK(cpu.negative() != 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+//
+
+BOOST_AUTO_TEST_SUITE(INC)
+
+BOOST_AUTO_TEST_CASE(INCA1) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x4c);
+	cpu.CC() = 0;
+	cpu.A() = 0x32;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0x33);
+	BOOST_CHECK_EQUAL(cpu.negative(), 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK_EQUAL(cpu.carry(), 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
+
+BOOST_AUTO_TEST_CASE(INCA2) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x4c);
+	cpu.CC() = 0;
+	cpu.A() = 0x7f;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0x80);
+	BOOST_CHECK(cpu.negative() != 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK(cpu.overflow() != 0);
+	BOOST_CHECK_EQUAL(cpu.carry(), 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
+
+BOOST_AUTO_TEST_CASE(INCA3) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x4c);
+	cpu.CC() = 0;
+	cpu.A() = 0xff;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0);
+	BOOST_CHECK_EQUAL(cpu.negative(), 0);
+	BOOST_CHECK(cpu.zero() != 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK_EQUAL(cpu.carry(), 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+//
+
+BOOST_AUTO_TEST_SUITE(SBC)
+
+BOOST_AUTO_TEST_CASE(Immediate_byte) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x82);
+	board.poke(1, 0x34);
+	cpu.A() = 0x14;
+	cpu.CC() = cpu.setBit(cpu.CC(), EightBit::mc6809::CF);
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0xdf);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK(cpu.negative() != 0);
+	BOOST_CHECK(cpu.carry() != 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
+
+// B=0x35 - addr(0x503)=0x3 - C=1 becomes 0x31
+BOOST_AUTO_TEST_CASE(SBCB_direct) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0xd2);
+	board.poke(1, 0x03);
+	board.poke(0x503, 0x03);
+	cpu.DP() = 5;
+	cpu.B() = 0x35;
+	cpu.CC() = EightBit::mc6809::CF;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.B(), 0x31);
+	BOOST_CHECK_EQUAL(cpu.carry(), 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK_EQUAL(cpu.negative(), 0);
+	BOOST_CHECK_EQUAL(cycles, 4);
+}
+
+// A=0xFF - 0xFE - C=1 becomes 0x00
+BOOST_AUTO_TEST_CASE(SBCA1) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x82);
+	board.poke(1, 0xfe);
+	board.poke(0x503, 0x03);
+	cpu.CC() = EightBit::mc6809::CF | EightBit::mc6809::NF;
+	cpu.A() = 0xff;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0);
+	BOOST_CHECK_EQUAL(cpu.carry(), 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK(cpu.zero() != 0);
+	BOOST_CHECK_EQUAL(cpu.negative(), 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
+
+// A=0x00 - 0xFF - C=0 becomes 0x01
+BOOST_AUTO_TEST_CASE(SBCA2) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x82);
+	board.poke(1, 0xff);
+	cpu.CC() = EightBit::mc6809::NF | EightBit::mc6809::VF;
+	cpu.A() = 0;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 1);
+	BOOST_CHECK(cpu.carry() != 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK_EQUAL(cpu.negative(), 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
+
+// A=0x00 - 0x01 - C=0 becomes 0xFF
+BOOST_AUTO_TEST_CASE(SBCA3) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x82);
+	board.poke(1, 0x01);
+	cpu.CC() = EightBit::mc6809::NF | EightBit::mc6809::VF;
+	cpu.A() = 0;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0xff);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK(cpu.negative() != 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+//
+
+BOOST_AUTO_TEST_SUITE(SUB)
+
+// A=0x00 - 0xFF becomes 0x01
+BOOST_AUTO_TEST_CASE(SUBA1) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x80);
+	board.poke(1, 0xff);
+	cpu.CC() = EightBit::mc6809::CF | EightBit::mc6809::NF | EightBit::mc6809::VF;
+	cpu.A() = 0;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 1);
+	BOOST_CHECK(cpu.carry() != 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK_EQUAL(cpu.negative(), 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
+
+// A=0x00 - 0x01 becomes 0xFF
+BOOST_AUTO_TEST_CASE(SUBA2) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x80);
+	board.poke(1, 1);
+	cpu.CC() = EightBit::mc6809::CF | EightBit::mc6809::NF | EightBit::mc6809::VF;
+	cpu.A() = 0;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 0xff);
+	BOOST_CHECK(cpu.negative() != 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK(cpu.carry() != 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
+
+// B=0x02 - 0xB3 becomes 0x4F
+BOOST_AUTO_TEST_CASE(SUBB1) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0xc0);
+	board.poke(1, 0xb3);
+	cpu.CC() = 0;
+	cpu.B() = 2;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.B(), 0x4f);
+	BOOST_CHECK_EQUAL(cpu.negative(), 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK(cpu.carry() != 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
+
+// B=0x02 - 0x81 becomes 0x81
+BOOST_AUTO_TEST_CASE(SUBB2) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0xc0);
+	board.poke(1, 0x81);
+	cpu.CC() = 0;
+	cpu.B() = 2;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.B(), 0x81);
+	BOOST_CHECK(cpu.negative() != 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK(cpu.overflow() != 0);
+	BOOST_CHECK(cpu.carry() != 0);
+	BOOST_CHECK_EQUAL(cycles, 2);
+}
+
+// 0x03 - 0x21 = 0xE2 (indexed: SUBB ,Y)
+BOOST_AUTO_TEST_CASE(SUBBY) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0xe0);
+	board.poke(1, 0xa4);
+	board.poke(0x21, 0x21);
+	cpu.CC() = EightBit::mc6809::ZF;
+	cpu.B() = 3;
+	cpu.Y() = 0x21;
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.B(), 0xe2);
+	BOOST_CHECK(cpu.negative() != 0);
+	BOOST_CHECK_EQUAL(cpu.zero(), 0);
+	BOOST_CHECK_EQUAL(cpu.overflow(), 0);
+	BOOST_CHECK(cpu.carry() != 0);
+	BOOST_CHECK_EQUAL(cycles, 4);
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+//
+
+BOOST_AUTO_TEST_SUITE(BGT)
+
+BOOST_AUTO_TEST_CASE(BGT1) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
 	board.poke(0, 0x2e);	// BGT
 	board.poke(1, 0x03);
-	board.poke(2, 0x86);	// LDA	#1
+	board.poke(2, 0x86);	// LDA #1
 	board.poke(3, 0x01);
 	board.poke(4, 0x12);	// NOP
-	board.poke(5, 0x86);	// LDA	#2
+	board.poke(5, 0x86);	// LDA #2
 	board.poke(6, 0x02);
 	board.poke(7, 0x12);	// NOP
-
-	SECTION("BGT1") {
-		cpu.A() = 0;
- 		cpu.CC() = EightBit::mc6809::ZF;
-		cycles = cpu.step();
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 1);
-	}
-
-	cpu.lowerRESET();
+	cpu.A() = 0;
+	cpu.CC() = EightBit::mc6809::ZF;
 	cycles = cpu.step();
-
-	SECTION("BGT2") {
-		REQUIRE(cpu.PC() == 0);
- 		cpu.CC() = 0;
-		cycles = cpu.step();
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 2);
-	}
-
-	cpu.lowerRESET();
 	cycles = cpu.step();
-
-	SECTION("BGT3") {
-		REQUIRE(cpu.PC() == 0);
- 		cpu.CC() = EightBit::mc6809::NF;
-		cycles = cpu.step();
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 1);
-	}
-
-	cpu.lowerRESET();
-	cycles = cpu.step();
-
-	SECTION("BGT4") {
-		REQUIRE(cpu.PC() == 0);
- 		cpu.CC() = EightBit::mc6809::NF | EightBit::mc6809::VF;
-		cycles = cpu.step();
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 2);
-	}
-
-	cpu.lowerRESET();
-	cycles = cpu.step();
-
-	SECTION("BGT5") {
-		REQUIRE(cpu.PC() == 0);
- 		cpu.CC() = EightBit::mc6809::ZF | EightBit::mc6809::NF;
-		cycles = cpu.step();
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 1);
-	}
+	BOOST_CHECK_EQUAL(cpu.A(), 1);
 }
 
-TEST_CASE(" Branch if Higher", "[BHI]") {
-
+BOOST_AUTO_TEST_CASE(BGT2) {
 	Board board;
 	board.raisePOWER();
 	auto& cpu = board.CPU();
 	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x2e);	// BGT
+	board.poke(1, 0x03);
+	board.poke(2, 0x86);	// LDA #1
+	board.poke(3, 0x01);
+	board.poke(4, 0x12);	// NOP
+	board.poke(5, 0x86);	// LDA #2
+	board.poke(6, 0x02);
+	board.poke(7, 0x12);	// NOP
+	cpu.lowerRESET();
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.PC(), 0);
+	cpu.CC() = 0;
+	cycles = cpu.step();
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 2);
+}
 
+BOOST_AUTO_TEST_CASE(BGT3) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x2e);	// BGT
+	board.poke(1, 0x03);
+	board.poke(2, 0x86);	// LDA #1
+	board.poke(3, 0x01);
+	board.poke(4, 0x12);	// NOP
+	board.poke(5, 0x86);	// LDA #2
+	board.poke(6, 0x02);
+	board.poke(7, 0x12);	// NOP
+	cpu.lowerRESET();
+	cycles = cpu.step();
+	cpu.lowerRESET();
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.PC(), 0);
+	cpu.CC() = EightBit::mc6809::NF;
+	cycles = cpu.step();
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 1);
+}
+
+BOOST_AUTO_TEST_CASE(BGT4) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x2e);	// BGT
+	board.poke(1, 0x03);
+	board.poke(2, 0x86);	// LDA #1
+	board.poke(3, 0x01);
+	board.poke(4, 0x12);	// NOP
+	board.poke(5, 0x86);	// LDA #2
+	board.poke(6, 0x02);
+	board.poke(7, 0x12);	// NOP
+	cpu.lowerRESET();
+	cycles = cpu.step();
+	cpu.lowerRESET();
+	cycles = cpu.step();
+	cpu.lowerRESET();
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.PC(), 0);
+	cpu.CC() = EightBit::mc6809::NF | EightBit::mc6809::VF;
+	cycles = cpu.step();
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 2);
+}
+
+BOOST_AUTO_TEST_CASE(BGT5) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x2e);	// BGT
+	board.poke(1, 0x03);
+	board.poke(2, 0x86);	// LDA #1
+	board.poke(3, 0x01);
+	board.poke(4, 0x12);	// NOP
+	board.poke(5, 0x86);	// LDA #2
+	board.poke(6, 0x02);
+	board.poke(7, 0x12);	// NOP
+	cpu.lowerRESET();
+	cycles = cpu.step();
+	cpu.lowerRESET();
+	cycles = cpu.step();
+	cpu.lowerRESET();
+	cycles = cpu.step();
+	cpu.lowerRESET();
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.PC(), 0);
+	cpu.CC() = EightBit::mc6809::ZF | EightBit::mc6809::NF;
+	cycles = cpu.step();
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 1);
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+//
+
+BOOST_AUTO_TEST_SUITE(BHI)
+
+BOOST_AUTO_TEST_CASE(BHI1) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
 	board.poke(0, 0x22);	// BHI
 	board.poke(1, 0x03);
-	board.poke(2, 0x86);	// LDA	#1
+	board.poke(2, 0x86);	// LDA #1
 	board.poke(3, 0x01);
 	board.poke(4, 0x12);	// NOP
-	board.poke(5, 0x86);	// LDA	#2
+	board.poke(5, 0x86);	// LDA #2
 	board.poke(6, 0x02);
 	board.poke(7, 0x12);	// NOP
-
-	SECTION("BHI1") {
-		cpu.A() = 0;
- 		cpu.CC() = EightBit::mc6809::ZF;
-		cycles = cpu.step();
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 1);
-	}
+	cpu.A() = 0;
+	cpu.CC() = EightBit::mc6809::ZF;
+	cycles = cpu.step();
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 1);
 }
 
-TEST_CASE("Branch on Less than or Equal to Zero", "[BLE]") {
+BOOST_AUTO_TEST_SUITE_END()
 
+//
+
+BOOST_AUTO_TEST_SUITE(BLE)
+
+BOOST_AUTO_TEST_CASE(BLE1) {
 	Board board;
 	board.raisePOWER();
 	auto& cpu = board.CPU();
 	auto cycles = cpu.step();	// Step over the reset
-
 	board.poke(0, 0x2f);	// BLE
 	board.poke(1, 0x03);
-	board.poke(2, 0x86);	// LDA	#1
+	board.poke(2, 0x86);	// LDA #1
 	board.poke(3, 0x01);
 	board.poke(4, 0x12);	// NOP
-	board.poke(5, 0x86);	// LDA	#2
+	board.poke(5, 0x86);	// LDA #2
 	board.poke(6, 0x02);
 	board.poke(7, 0x12);	// NOP
-
-	SECTION("BLE1") {
-		cpu.A() = 0;
-		cpu.CC() = EightBit::mc6809::ZF;
-		cycles = cpu.step();
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 2);
-	}
-
-	cpu.lowerRESET();
+	cpu.A() = 0;
+	cpu.CC() = EightBit::mc6809::ZF;
 	cycles = cpu.step();
-
-	SECTION("BLE2") {
-		cpu.A() = 0;
-		cpu.CC() = 0;
-		cycles = cpu.step();
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 1);
-	}
-
-	cpu.lowerRESET();
 	cycles = cpu.step();
-
-	SECTION("BLE3") {
-		cpu.A() = 0;
-		cpu.CC() = EightBit::mc6809::NF;
-		cycles = cpu.step();
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 2);
-	}
-
-	cpu.lowerRESET();
-	cycles = cpu.step();
-
-	SECTION("BLE4") {
-		cpu.A() = 0;
-		cpu.CC() = EightBit::mc6809::NF | EightBit::mc6809::VF;
-		cycles = cpu.step();
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 1);
-	}
-
-	cpu.lowerRESET();
-	cycles = cpu.step();
-
-	SECTION("BLE5") {
-		cpu.A() = 0;
-		cpu.CC() = EightBit::mc6809::ZF | EightBit::mc6809::NF;
-		cycles = cpu.step();
-		cycles = cpu.step();
-		REQUIRE(cpu.A() == 2);
-	}
+	BOOST_CHECK_EQUAL(cpu.A(), 2);
 }
 
-TEST_CASE("Subroutines", "[JSR][RTS]") {
+BOOST_AUTO_TEST_CASE(BLE2) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x2f);	// BLE
+	board.poke(1, 0x03);
+	board.poke(2, 0x86);	// LDA #1
+	board.poke(3, 0x01);
+	board.poke(4, 0x12);	// NOP
+	board.poke(5, 0x86);	// LDA #2
+	board.poke(6, 0x02);
+	board.poke(7, 0x12);	// NOP
+	cpu.lowerRESET();
+	cycles = cpu.step();
+	cpu.A() = 0;
+	cpu.CC() = 0;
+	cycles = cpu.step();
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 1);
+}
 
+BOOST_AUTO_TEST_CASE(BLE3) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x2f);	// BLE
+	board.poke(1, 0x03);
+	board.poke(2, 0x86);	// LDA #1
+	board.poke(3, 0x01);
+	board.poke(4, 0x12);	// NOP
+	board.poke(5, 0x86);	// LDA #2
+	board.poke(6, 0x02);
+	board.poke(7, 0x12);	// NOP
+	cpu.lowerRESET();
+	cycles = cpu.step();
+	cpu.lowerRESET();
+	cycles = cpu.step();
+	cpu.A() = 0;
+	cpu.CC() = EightBit::mc6809::NF;
+	cycles = cpu.step();
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 2);
+}
+
+BOOST_AUTO_TEST_CASE(BLE4) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x2f);	// BLE
+	board.poke(1, 0x03);
+	board.poke(2, 0x86);	// LDA #1
+	board.poke(3, 0x01);
+	board.poke(4, 0x12);	// NOP
+	board.poke(5, 0x86);	// LDA #2
+	board.poke(6, 0x02);
+	board.poke(7, 0x12);	// NOP
+	cpu.lowerRESET();
+	cycles = cpu.step();
+	cpu.lowerRESET();
+	cycles = cpu.step();
+	cpu.lowerRESET();
+	cycles = cpu.step();
+	cpu.A() = 0;
+	cpu.CC() = EightBit::mc6809::NF | EightBit::mc6809::VF;
+	cycles = cpu.step();
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 1);
+}
+
+BOOST_AUTO_TEST_CASE(BLE5) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
+	board.poke(0, 0x2f);	// BLE
+	board.poke(1, 0x03);
+	board.poke(2, 0x86);	// LDA #1
+	board.poke(3, 0x01);
+	board.poke(4, 0x12);	// NOP
+	board.poke(5, 0x86);	// LDA #2
+	board.poke(6, 0x02);
+	board.poke(7, 0x12);	// NOP
+	cpu.lowerRESET();
+	cycles = cpu.step();
+	cpu.lowerRESET();
+	cycles = cpu.step();
+	cpu.lowerRESET();
+	cycles = cpu.step();
+	cpu.lowerRESET();
+	cycles = cpu.step();
+	cpu.A() = 0;
+	cpu.CC() = EightBit::mc6809::ZF | EightBit::mc6809::NF;
+	cycles = cpu.step();
+	cycles = cpu.step();
+	BOOST_CHECK_EQUAL(cpu.A(), 2);
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+//
+
+BOOST_AUTO_TEST_SUITE(Subroutines)
+
+// JSR D,Y (indexed)
+BOOST_AUTO_TEST_CASE(JSR) {
 	Board board;
 	board.raisePOWER();
 	auto& cpu = board.CPU();
 	auto cycles = cpu.step();	// Step over the reset
 
-	// Test the JSR - Jump to Subroutine - instruction.
-	// INDEXED mode:   JSR   D,Y
-	SECTION("JSR") {
+	cpu.pokeShort(0x205, 0x03ff);
+	cpu.D() = 0x105;
+	cpu.Y() = 0x200;
+	cpu.S() = 0x915;
+	board.poke(0xB00, 0xAD);
+	board.poke(0xB01, 0xAB);
+	board.poke(0xB02, 0x11);	// Junk
+	board.poke(0xB03, 0x22);	// Junk
+	cpu.PC() = 0xB00;
+	cpu.CC() = 0;
+	cycles = cpu.step();
 
-		// Set up a word to test at address 0x205
-		cpu.pokeShort(0x205, 0x03ff);
+	BOOST_CHECK_EQUAL(cpu.CC(), 0);
+	BOOST_CHECK_EQUAL(cpu.A(), 1);
+	BOOST_CHECK_EQUAL(cpu.B(), 5);
+	BOOST_CHECK_EQUAL(cpu.DP(), 0);
+	BOOST_CHECK_EQUAL(cpu.X(), 0);
+	BOOST_CHECK_EQUAL(cpu.Y(), 0x200);
+	BOOST_CHECK_EQUAL(cpu.D(), 0x105);
+	BOOST_CHECK_EQUAL(cpu.S(), 0x913);
+	BOOST_CHECK_EQUAL(cpu.U(), 0);
+	BOOST_CHECK_EQUAL(cpu.PC(), 0x305);
+	BOOST_CHECK_EQUAL(board.peek(0x914), 2);
+	BOOST_CHECK_EQUAL(board.peek(0x913), 0xb);
+	BOOST_CHECK_EQUAL(cycles, 11);
+}
 
-		// Set register D
-		cpu.D() = 0x105;
-
-		// Set register Y to point to that location minus 5
-		cpu.Y() = 0x200;
-
-		// Set register S to point to 0x915
-		cpu.S() = 0x915;
-
-		// Two bytes of instruction
-		board.poke(0xB00, 0xAD);
-		board.poke(0xB01, 0xAB);
-		board.poke(0xB02, 0x11); // Junk
-		board.poke(0xB03, 0x22); // Junk
-
-		cpu.PC() = 0xB00;
-		cpu.CC() = 0;
-
-		cycles = cpu.step();
-
-		REQUIRE(cpu.CC() == 0);
-		REQUIRE(cpu.A() == 1);
-		REQUIRE(cpu.B() == 5);
-		REQUIRE(cpu.DP() == 0);
-		REQUIRE(cpu.X() == 0);
-		REQUIRE(cpu.Y() == 0x200);
-		REQUIRE(cpu.D() == 0x105);
-		REQUIRE(cpu.S() == 0x913);
-		REQUIRE(cpu.U() == 0);
-		REQUIRE(cpu.PC() == 0x305);
-
-		REQUIRE(board.peek(0x914) == 2);
-		REQUIRE(board.peek(0x913) == 0xb);
-
-		REQUIRE(cycles == 11);
-	}
+BOOST_AUTO_TEST_CASE(RTS) {
+	Board board;
+	board.raisePOWER();
+	auto& cpu = board.CPU();
+	auto cycles = cpu.step();	// Step over the reset
 
 	cpu.lowerRESET();
 	cycles = cpu.step();
 
-	SECTION("RTS") {
+	cpu.S() = 0x300;
+	cpu.pokeShort(0x300, 0x102C);	// Write return address
+	board.poke(0xB00, 0x39);		// RTS
+	cpu.PC() = 0xB00;
+	cycles = cpu.step();
 
-		cpu.S().word = 0x300;
-
-		cpu.pokeShort(0x300, 0x102C); // Write return address
-		board.poke(0xB00, 0x39); // RTS
-
-		cpu.PC().word = 0xB00;
-
-		cycles = cpu.step();
-
-		REQUIRE(cpu.PC().word == 0x102C);
-		REQUIRE(cpu.S().word == 0x302);
-		REQUIRE(cycles == 5);
-	}
+	BOOST_CHECK_EQUAL(cpu.PC(), 0x102C);
+	BOOST_CHECK_EQUAL(cpu.S(), 0x302);
+	BOOST_CHECK_EQUAL(cycles, 5);
 }
+
+BOOST_AUTO_TEST_SUITE_END()
diff --git a/MC6809/unittest/pch.h b/MC6809/unittest/pch.h
index d36b3a5..43f7416 100644
Binary files a/MC6809/unittest/pch.h and b/MC6809/unittest/pch.h differ
diff --git a/MC6809/unittest/unittest_MC6809.cpp b/MC6809/unittest/unittest_MC6809.cpp
index d2bef69..da8f85f 100644
Binary files a/MC6809/unittest/unittest_MC6809.cpp and b/MC6809/unittest/unittest_MC6809.cpp differ
diff --git a/MC6809/unittest/unittest_MC6809.vcxproj b/MC6809/unittest/unittest_MC6809.vcxproj
index 8f37b71..2067976 100644
--- a/MC6809/unittest/unittest_MC6809.vcxproj
+++ b/MC6809/unittest/unittest_MC6809.vcxproj
@@ -66,19 +66,19 @@
   <PropertyGroup Label="UserMacros" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
     <LinkIncremental>false</LinkIncremental>
-    <IncludePath>..\inc;..\..\inc;..\..\MC6850\inc;$(SolutionDir)modules\catch2\single_include\catch2;$(IncludePath)</IncludePath>
+    <IncludePath>..\inc;..\..\inc;..\..\MC6850\inc;C:\Libraries\boost_1_88_0;$(IncludePath)</IncludePath>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
     <LinkIncremental>true</LinkIncremental>
-    <IncludePath>..\inc;..\..\inc;..\..\MC6850\inc;$(SolutionDir)modules\catch2\single_include\catch2;$(IncludePath)</IncludePath>
+    <IncludePath>..\inc;..\..\inc;..\..\MC6850\inc;C:\Libraries\boost_1_88_0;$(IncludePath)</IncludePath>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
     <LinkIncremental>true</LinkIncremental>
-    <IncludePath>..\inc;..\..\inc;..\..\MC6850\inc;$(SolutionDir)modules\catch2\single_include\catch2;$(IncludePath)</IncludePath>
+    <IncludePath>..\inc;..\..\inc;..\..\MC6850\inc;C:\Libraries\boost_1_88_0;$(IncludePath)</IncludePath>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
     <LinkIncremental>false</LinkIncremental>
-    <IncludePath>..\inc;..\..\inc;..\..\MC6850\inc;$(SolutionDir)modules\catch2\single_include\catch2;$(IncludePath)</IncludePath>
+    <IncludePath>..\inc;..\..\inc;..\..\MC6850\inc;C:\Libraries\boost_1_88_0;$(IncludePath)</IncludePath>
   </PropertyGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
     <ClCompile>