diff --git a/MC6809/inc/mc6809.h b/MC6809/inc/mc6809.h
index 7f4e2ff..c836e37 100644
--- a/MC6809/inc/mc6809.h
+++ b/MC6809/inc/mc6809.h
@@ -77,6 +77,9 @@ namespace EightBit {
 	protected:
 		virtual void reset() final;
 
+		virtual void push(uint8_t value) final { pushS(value);  }
+		virtual uint8_t pop() final { return popS(); }
+
 	private:
 		const uint8_t RESETvector = 0xfe;		// RESET vector
 		const uint8_t NMIvector = 0xfc;			// NMI vector
@@ -87,6 +90,33 @@ namespace EightBit {
 		const uint8_t SWI3vector = 0xf2;		// SWI3 vector
 		const uint8_t RESERVEDvector = 0xf0;	// RESERVED vector
 
+		// Stack manipulation
+
+		void push(register16_t& stack, uint8_t value);
+		void pushS(uint8_t value) { push(S(), value); }
+		void pushU(uint8_t value) { push(U(), value); }
+
+		void pushWord(register16_t& stack, register16_t value) {
+			push(stack, value.low);
+			push(stack, value.high);
+		}
+
+		void pushWordS(register16_t value) { pushWord(S(), value); }
+		void pushWordU(register16_t value) { pushWord(U(), value); }
+
+		uint8_t pop(register16_t& stack);
+		uint8_t popS() { return pop(S()); }
+		uint8_t popU() { return pop(U()); }
+
+		register16_t popWord(register16_t& stack) {
+			const auto high = pop(stack);
+			const auto low = pop(stack);
+			return register16_t(low, high);
+		}
+
+		register16_t popWordS() { popWord(S()); }
+		register16_t popWordU() { popWord(U()); }
+
 		// Execution helpers
 
 		int executeUnprefixed(uint8_t opcode);
@@ -216,6 +246,10 @@ namespace EightBit {
 		register16_t mul(uint8_t first, uint8_t second);
 		uint8_t neg(uint8_t operand);
 		uint8_t orr(uint8_t operand, uint8_t data);
+		void pshs(uint8_t data);
+		void pshu(uint8_t data);
+		void puls(uint8_t data);
+		void pulu(uint8_t data);
 
 		register16_t m_d;
 		register16_t m_x;
diff --git a/MC6809/src/mc6809.cpp b/MC6809/src/mc6809.cpp
index a0c9e67..5185fe7 100644
--- a/MC6809/src/mc6809.cpp
+++ b/MC6809/src/mc6809.cpp
@@ -272,6 +272,14 @@ int EightBit::mc6809::executeUnprefixed(uint8_t opcode) {
 	// ORCC
 	case 0x1a:	addCycles(3);	CC() |= AM_immediate_byte();			break;		// OR (ORCC immediate)
 
+	// PSH
+	case 0x34:	addCycles(5);	pshs(AM_immediate_byte());				break;		// PSH (PSHS immediate)
+	case 0x36:	addCycles(5);	pshu(AM_immediate_byte());				break;		// PSH (PSHU immediate)
+
+	// PUL
+	case 0x35:	addCycles(5);	puls(AM_immediate_byte());				break;		// PUL (PULS immediate)
+	case 0x37:	addCycles(5);	pulu(AM_immediate_byte());				break;		// PUL (PULU immediate)
+
 	default:
 		UNREACHABLE;
 	}
@@ -364,6 +372,16 @@ int EightBit::mc6809::execute11(uint8_t opcode) {
 
 //
 
+void EightBit::mc6809::push(register16_t& stack, uint8_t value) {
+	BUS().write(stack--, value);
+}
+
+uint8_t EightBit::mc6809::pop(register16_t& stack) {
+	return BUS().read(++stack);
+}
+
+//
+
 EightBit::register16_t& EightBit::mc6809::RR(int which) {
 	ASSUME(which >= 0);
 	ASSUME(which <= 3);
@@ -564,14 +582,14 @@ uint8_t EightBit::mc6809::com(uint8_t operand) {
 
 void EightBit::mc6809::cwai(uint8_t data) {
 	CC() &= data;
-	pushWord(PC());
-	pushWord(U());
-	pushWord(Y());
-	pushWord(X());
-	push(DP());
-	push(B());
-	push(A());
-	push(CC());
+	pushWordS(PC());
+	pushWordS(U());
+	pushWordS(Y());
+	pushWordS(X());
+	pushS(DP());
+	pushS(B());
+	pushS(A());
+	pushS(CC());
 	halt();
 }
 
@@ -698,3 +716,79 @@ uint8_t EightBit::mc6809::orr(uint8_t operand, uint8_t data) {
 	adjustNZ(operand |= data);
 	return operand;
 }
+
+void EightBit::mc6809::pshs(uint8_t data) {
+	if (data & Bit7)
+		pushWordS(PC());
+	if (data & Bit6)
+		pushWordS(U());
+	if (data & Bit5)
+		pushWordS(Y());
+	if (data & Bit4)
+		pushWordS(X());
+	if (data & Bit3)
+		pushS(DP());
+	if (data & Bit2)
+		pushS(B());
+	if (data & Bit1)
+		pushS(A());
+	if (data & Bit0)
+		pushS(CC());
+}
+
+void EightBit::mc6809::pshu(uint8_t data) {
+	if (data & Bit7)
+		pushWordS(PC());
+	if (data & Bit6)
+		pushWordS(S());
+	if (data & Bit5)
+		pushWordS(Y());
+	if (data & Bit4)
+		pushWordS(X());
+	if (data & Bit3)
+		pushS(DP());
+	if (data & Bit2)
+		pushS(B());
+	if (data & Bit1)
+		pushS(A());
+	if (data & Bit0)
+		pushS(CC());
+}
+
+void EightBit::mc6809::puls(uint8_t data) {
+	if (data & Bit0)
+		pushS(CC());
+	if (data & Bit1)
+		pushS(A());
+	if (data & Bit2)
+		pushS(B());
+	if (data & Bit3)
+		pushS(DP());
+	if (data & Bit4)
+		pushWordS(X());
+	if (data & Bit5)
+		pushWordS(Y());
+	if (data & Bit6)
+		pushWordS(U());
+	if (data & Bit7)
+		pushWordS(PC());
+}
+
+void EightBit::mc6809::pulu(uint8_t data) {
+	if (data & Bit0)
+		pushS(CC());
+	if (data & Bit1)
+		pushS(A());
+	if (data & Bit2)
+		pushS(B());
+	if (data & Bit3)
+		pushS(DP());
+	if (data & Bit4)
+		pushWordS(X());
+	if (data & Bit5)
+		pushWordS(Y());
+	if (data & Bit6)
+		pushWordS(S());
+	if (data & Bit7)
+		pushWordS(PC());
+}