diff --git a/src/main/java/com/loomcom/symon/Main.java b/src/main/java/com/loomcom/symon/Main.java
index 78d7b59..a1b2096 100644
--- a/src/main/java/com/loomcom/symon/Main.java
+++ b/src/main/java/com/loomcom/symon/Main.java
@@ -40,9 +40,9 @@ public class Main {
      *
      * @param args
      */
-    public static void main(String args[]) {
+    public static void main(String args[]) throws Exception {
         
-        Class machineClass = null;
+        Class machineClass = SymonMachine.class;
         for(int i = 0; i < args.length; ++i) {
             String arg = args[i].toLowerCase(Locale.ENGLISH);
             if(arg.equals("-machine") && (i+1) < args.length) {
@@ -55,38 +55,46 @@ public class Main {
             }
         }
         
-        if(machineClass == null) {
-            Object[] possibilities = {"Symon", "Multicomp"};
-            String s = (String)JOptionPane.showInputDialog(
-                            null,
-                            "Please choose the machine type to be emulated:",
-                            "Machine selection",
-                            JOptionPane.PLAIN_MESSAGE,
-                            null,
-                            possibilities,
-                            "Symon");
-            if(s.equals("Symon")) {
-                machineClass = SymonMachine.class;
-            } else {
-                machineClass = MulticompMachine.class;
-            }
-        }
-        
-        
-        final Class mClass = machineClass;
-        SwingUtilities.invokeLater(new Runnable() {
-            public void run() {
-                try {
-                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
-                    // Create the main UI window
-                    Simulator simulator = new Simulator(mClass);
-                    simulator.createAndShowUi();
-                } catch (Exception e) {
-                    e.printStackTrace();
+        while(true) {        
+            if(machineClass == null) {
+                Object[] possibilities = {"Symon", "Multicomp"};
+                String s = (String)JOptionPane.showInputDialog(
+                                null,
+                                "Please choose the machine type to be emulated:",
+                                "Machine selection",
+                                JOptionPane.PLAIN_MESSAGE,
+                                null,
+                                possibilities,
+                                "Symon");
+                if(s.equals("Symon")) {
+                    machineClass = SymonMachine.class;
+                } else {
+                    machineClass = MulticompMachine.class;
                 }
             }
-        });
         
+            final Simulator simulator = new Simulator(machineClass);
+        
+            SwingUtilities.invokeLater(new Runnable() {
+                public void run() {
+                    try {
+                        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
+                        // Create the main UI window
+                        simulator.createAndShowUi();
+                    } catch (Exception e) {
+                        e.printStackTrace();
+                    }
+                }
+            });
+        
+        
+            Simulator.MAIN_CMD cmd = simulator.waitForCommand();
+            if(cmd.equals(Simulator.MAIN_CMD.SELECTMACHINE)) {
+                machineClass = null;
+            } else {
+                break;
+            }
+        }
        
     }
     
diff --git a/src/main/java/com/loomcom/symon/Simulator.java b/src/main/java/com/loomcom/symon/Simulator.java
index b064d5b..161c9d4 100644
--- a/src/main/java/com/loomcom/symon/Simulator.java
+++ b/src/main/java/com/loomcom/symon/Simulator.java
@@ -116,6 +116,13 @@ public class Simulator {
     private JFileChooser      fileChooser;
     private PreferencesDialog preferences;
 
+    private final Object commandMonitorObject = new Object();
+    private MAIN_CMD command = MAIN_CMD.NONE;
+    public static enum MAIN_CMD  {
+        NONE,
+        SELECTMACHINE
+    }
+    
     /**
      * The list of step counts that will appear in the "Step" drop-down.
      */
@@ -230,6 +237,18 @@ public class Simulator {
         console.requestFocus();
         handleReset();
     }
+    
+    public MAIN_CMD waitForCommand() {
+        synchronized(commandMonitorObject) {
+            try {
+                commandMonitorObject.wait();
+            } catch (InterruptedException ex) {
+                ex.printStackTrace();
+            }
+        }
+        return command;
+    }
+    
 
     private void handleStart() {
         // Shift focus to the console.
@@ -543,6 +562,34 @@ public class Simulator {
             preferences.getDialog().setVisible(true);
         }
     }
+    
+    class SelectMachineAction extends AbstractAction {
+        Simulator simulator;
+        
+        public SelectMachineAction() {
+            super("Switch emulated machine...", null);
+            putValue(SHORT_DESCRIPTION, "Select the type of the machine to be emulated");
+            putValue(MNEMONIC_KEY, KeyEvent.VK_M);
+        }
+
+        public void actionPerformed(ActionEvent actionEvent) {
+            if(runLoop != null) {
+                runLoop.requestStop();
+            }
+
+            memoryWindow.dispose();
+            traceLog.dispose();
+            if(videoWindow != null) {
+                videoWindow.dispose();
+            }
+            mainWindow.dispose();
+
+            command = MAIN_CMD.SELECTMACHINE;
+            synchronized(commandMonitorObject) {
+                commandMonitorObject.notifyAll();
+            }
+        }
+    }
 
     class QuitAction extends AbstractAction {
         public QuitAction() {
@@ -669,11 +716,13 @@ public class Simulator {
             loadProgramItem = new JMenuItem(new LoadProgramAction());
             loadRomItem = new JMenuItem(new LoadRomAction());
             JMenuItem prefsItem = new JMenuItem(new ShowPrefsAction());
+            JMenuItem selectMachineItem = new JMenuItem(new SelectMachineAction());
             JMenuItem quitItem = new JMenuItem(new QuitAction());
 
             fileMenu.add(loadProgramItem);
             fileMenu.add(loadRomItem);
             fileMenu.add(prefsItem);
+            fileMenu.add(selectMachineItem);
             fileMenu.add(quitItem);
 
             add(fileMenu);