Pushes far enough along the path of having the SDL version do work that it becomes obvious I've never figured out the correct course of action if there is no sound output.

Machines/Utility/MachineForTarget.hpp

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+//
+//  MachineForTarget.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 04/11/2017.
+//  Copyright © 2017 Thomas Harte. All rights reserved.
+//
+
+#ifndef MachineForTarget_hpp
+#define MachineForTarget_hpp
+
+#include "../../StaticAnalyser/StaticAnalyser.hpp"
+
+#include "../ConfigurationTarget.hpp"
+#include "../CRTMachine.hpp"
+#include "../JoystickMachine.hpp"
+#include "../KeyboardMachine.hpp"
+
+namespace Machine {
+
+/*!
+	Provides the structure for owning a machine and dynamically casting it as desired without knowledge of
+	the machine's parent class or, therefore, the need to establish a common one.
+*/
+struct DynamicMachine {
+	virtual ConfigurationTarget::Machine *configuration_target() = 0;
+	virtual CRTMachine::Machine *crt_machine() = 0;
+	virtual JoystickMachine::Machine *joystick_machine() = 0;
+	virtual KeyboardMachine::Machine *keyboard_machine() = 0;
+};
+
+/*!
+	Allocates an instance of DynamicMachine holding a machine that can
+	receive the supplied target. The machine has been allocated on the heap.
+	It is the caller's responsibility to delete the class when finished.
+*/
+DynamicMachine *MachineForTarget(const StaticAnalyser::Target &target);
+
+}
+
+#endif /* MachineForTarget_hpp */