diff --git a/Analyser/Static/PCCompatible/Target.hpp b/Analyser/Static/PCCompatible/Target.hpp
index 0d7c3f759..271bdabcb 100644
--- a/Analyser/Static/PCCompatible/Target.hpp
+++ b/Analyser/Static/PCCompatible/Target.hpp
@@ -20,10 +20,17 @@ struct Target: public Analyser::Static::Target, public Reflection::StructImpl<Ta
 		CGA);
 	VideoAdaptor adaptor = VideoAdaptor::CGA;
 
+	ReflectableEnum(Speed,
+		Original,
+		Fast);
+	Speed speed = Speed::Fast;
+
 	Target() : Analyser::Static::Target(Machine::PCCompatible) {
 		if(needs_declare()) {
-			DeclareField(adaptor);
 			AnnounceEnum(VideoAdaptor);
+			AnnounceEnum(Speed);
+			DeclareField(adaptor);
+			DeclareField(speed);
 		}
 	}
 };
diff --git a/Machines/PCCompatible/PCCompatible.cpp b/Machines/PCCompatible/PCCompatible.cpp
index c32b02345..fa2c5221d 100644
--- a/Machines/PCCompatible/PCCompatible.cpp
+++ b/Machines/PCCompatible/PCCompatible.cpp
@@ -1236,10 +1236,18 @@ Machine *Machine::PCCompatible(const Analyser::Static::Target *target, const ROM
 	using Target = Analyser::Static::PCCompatible::Target;
 	const Target *const pc_target = dynamic_cast<const Target *>(target);
 
-	switch(pc_target->adaptor) {
-		case VideoAdaptor::MDA:	return new PCCompatible::ConcreteMachine<VideoAdaptor::MDA, false>(*pc_target, rom_fetcher);
-		case VideoAdaptor::CGA:	return new PCCompatible::ConcreteMachine<VideoAdaptor::CGA, false>(*pc_target, rom_fetcher);
-		default: return nullptr;
+	if(pc_target->speed == Target::Speed::Fast) {
+		switch(pc_target->adaptor) {
+			case VideoAdaptor::MDA:	return new PCCompatible::ConcreteMachine<VideoAdaptor::MDA, true>(*pc_target, rom_fetcher);
+			case VideoAdaptor::CGA:	return new PCCompatible::ConcreteMachine<VideoAdaptor::CGA, true>(*pc_target, rom_fetcher);
+			default: return nullptr;
+		}
+	} else {
+		switch(pc_target->adaptor) {
+			case VideoAdaptor::MDA:	return new PCCompatible::ConcreteMachine<VideoAdaptor::MDA, false>(*pc_target, rom_fetcher);
+			case VideoAdaptor::CGA:	return new PCCompatible::ConcreteMachine<VideoAdaptor::CGA, false>(*pc_target, rom_fetcher);
+			default: return nullptr;
+		}
 	}
 }
 
diff --git a/OSBindings/Mac/Clock Signal.xcodeproj/xcshareddata/xcschemes/Clock Signal.xcscheme b/OSBindings/Mac/Clock Signal.xcodeproj/xcshareddata/xcschemes/Clock Signal.xcscheme
index 474fa352e..19b54b90e 100644
--- a/OSBindings/Mac/Clock Signal.xcodeproj/xcshareddata/xcschemes/Clock Signal.xcscheme	
+++ b/OSBindings/Mac/Clock Signal.xcodeproj/xcshareddata/xcschemes/Clock Signal.xcscheme	
@@ -62,7 +62,7 @@
       </Testables>
    </TestAction>
    <LaunchAction
-      buildConfiguration = "Debug"
+      buildConfiguration = "Release"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
       enableASanStackUseAfterReturn = "YES"