diff --git a/InstructionSets/x86/Implementation/PerformImplementation.hpp b/InstructionSets/x86/Implementation/PerformImplementation.hpp
index af4602a33..aacad8c6d 100644
--- a/InstructionSets/x86/Implementation/PerformImplementation.hpp
+++ b/InstructionSets/x86/Implementation/PerformImplementation.hpp
@@ -1460,6 +1460,16 @@ void stos(const InstructionT &instruction, AddressT &eCX, AddressT &eDI, IntT &e
 	repeat<AddressT>(instruction, eCX, flow_controller);
 }
 
+template <typename IntT, typename IOT>
+void out(uint16_t port, IntT value, IOT &io) {
+	io.template out<IntT>(port, value);
+}
+
+template <typename IntT, typename IOT>
+void in(uint16_t port, IntT &value, IOT &io) {
+	value = io.template in<IntT>(port);
+}
+
 }
 
 template <
@@ -1476,7 +1486,7 @@ template <
 	FlowControllerT &flow_controller,
 	RegistersT &registers,
 	MemoryT &memory,
-	[[maybe_unused]] IOT &io
+	IOT &io
 ) {
 	using IntT = typename DataSizeType<data_size>::type;
 	using AddressT = uint16_t;	// TODO.
@@ -1693,6 +1703,23 @@ template <
 			}
 		return;
 
+		case Operation::OUT: {
+			uint16_t port;
+			switch(instruction.destination().source()) {
+				case Source::DirectAddress:	port = instruction.operand();	break;
+				default:					port = registers.dx();			break;
+			}
+			Primitive::out(port, pair_low(), io);
+		} return;
+		case Operation::IN: {
+			uint16_t port;
+			switch(instruction.source().source()) {
+				case Source::DirectAddress:	port = instruction.operand();	break;
+				default:					port = registers.dx();			break;
+			}
+			Primitive::in(port, pair_low(), io);
+		} return;
+
 		case Operation::XLAT:	Primitive::xlat<AddressT>(instruction, memory, registers);	return;
 
 		case Operation::POP:	source() = Primitive::pop<IntT>(memory, registers);		break;
diff --git a/OSBindings/Mac/Clock SignalTests/8088Tests.mm b/OSBindings/Mac/Clock SignalTests/8088Tests.mm
index 2fd82d375..d63b25555 100644
--- a/OSBindings/Mac/Clock SignalTests/8088Tests.mm	
+++ b/OSBindings/Mac/Clock SignalTests/8088Tests.mm	
@@ -179,6 +179,8 @@ struct Memory {
 	uint16_t write_back_value_;
 };
 struct IO {
+	template <typename IntT> void out([[maybe_unused]] uint16_t port, [[maybe_unused]] IntT value) {}
+	template <typename IntT> IntT in([[maybe_unused]] uint16_t port) { return IntT(~0); }
 };
 class FlowController {
 	public:
@@ -352,9 +354,15 @@ struct FailedExecution {
 		@"4C.json.gz",	@"4D.json.gz",	@"4E.json.gz",	@"4F.json.gz",
 		@"FE.1.json.gz",
 		@"FF.1.json.gz",
+*/
+		// OUT
+		@"E6.json.gz",	@"E7.json.gz",
+		@"EE.json.gz",	@"EF.json.gz",
 
-		// TODO: IN, OUT
-
+		// IN
+		@"E4.json.gz",	@"E5.json.gz",
+		@"EC.json.gz",	@"ED.json.gz",
+/*
 		@"70.json.gz",	// JO
 		@"71.json.gz",	// JNO
 		@"72.json.gz",	// JB
@@ -413,11 +421,11 @@ struct FailedExecution {
 		// STOS
 		@"AA.json.gz",	@"AB.json.gz",
 
-		// TODO: INS, OUTS
-*/
 		// SCAS
 		@"AE.json.gz",	@"AF.json.gz",
-/*
+
+		// TODO: INS, OUTS
+
 		@"E0.json.gz",	// LOOPNE
 		@"E1.json.gz",	// LOOPE
 		@"E2.json.gz",	// LOOP