Implement SimpleMachine

src/main/java/com/loomcom/symon/Main.java

@@ -26,6 +26,7 @@
 package com.loomcom.symon;
 
 import com.loomcom.symon.machines.MulticompMachine;
+import com.loomcom.symon.machines.SimpleMachine;
 import com.loomcom.symon.machines.SymonMachine;
 import java.util.Locale;
 import javax.swing.JOptionPane;
@@ -51,13 +52,15 @@ public class Main {
                     machineClass = SymonMachine.class;
                 } else if(machine.equals("multicomp")) {
                     machineClass = MulticompMachine.class;
+                } else if (machine.equals("simple")) {
+                    machineClass = SimpleMachine.class;
                 }
             }
         }
         
         while(true) {        
             if(machineClass == null) {
-                Object[] possibilities = {"Symon", "Multicomp"};
+                Object[] possibilities = {"Symon", "Multicomp", "Simple"};
                 String s = (String)JOptionPane.showInputDialog(
                                 null,
                                 "Please choose the machine type to be emulated:",
@@ -67,11 +70,15 @@ public class Main {
                                 possibilities,
                                 "Symon");
                 
-                
-                if(s != null && s.equals("Multicomp")) {
-                    machineClass = MulticompMachine.class;
-                } else {
-                    machineClass = SymonMachine.class;
+
+                if (s != null) {
+                    if (s.equals("Multicomp")) {
+                        machineClass = MulticompMachine.class;
+                    } else if (s.equals("Simple")) {
+                        machineClass = SimpleMachine.class;
+                    } else {
+                        machineClass = SymonMachine.class;
+                    }
                 }
             }
         

src/main/java/com/loomcom/symon/Simulator.java

@@ -137,7 +137,7 @@ public class Simulator {
      */
     public void createAndShowUi() throws IOException {
         mainWindow = new JFrame();
-        mainWindow.setTitle("Symon 6502 Simulator");
+        mainWindow.setTitle("6502 Simulator - " + machine.getName());
         mainWindow.setResizable(false);
         mainWindow.getContentPane().setLayout(new BorderLayout());
 
@@ -337,7 +337,7 @@ public class Simulator {
 
         // Read from the ACIA and immediately update the console if there's
         // output ready.
-        if (machine.getAcia().hasTxChar()) {
+        if (machine.getAcia() != null && machine.getAcia().hasTxChar()) {
             // This is thread-safe
             console.print(Character.toString((char) machine.getAcia().txRead()));
             console.repaint();
@@ -346,7 +346,7 @@ public class Simulator {
         // If a key has been pressed, fill the ACIA.
         // TODO: Interrupt handling.
         try {
-            if (console.hasInput()) {
+            if (machine.getAcia() != null && console.hasInput()) {
                 machine.getAcia().rxWrite((int) console.readInputChar());
             }
         } catch (FifoUnderrunException ex) {
@@ -703,7 +703,9 @@ public class Simulator {
          */
         public void simulatorDidStart() {
             loadProgramItem.setEnabled(false);
-            loadRomItem.setEnabled(false);
+            if (loadRomItem != null) {
+                loadRomItem.setEnabled(false);
+            }
         }
 
         /**
@@ -711,7 +713,9 @@ public class Simulator {
          */
         public void simulatorDidStop() {
             loadProgramItem.setEnabled(true);
-            loadRomItem.setEnabled(true);
+            if (loadRomItem != null) {
+                loadRomItem.setEnabled(true);
+            }
         }
 
         private void initMenu() {
@@ -722,15 +726,22 @@ public class Simulator {
             JMenu fileMenu = new JMenu("File");
 
             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);
+
+            // Simple Machine does not implement a ROM, so it makes no sense to
+            // offer a ROM load option.
+            if (machine.getRom() != null) {
+                loadRomItem = new JMenuItem(new LoadRomAction());
+                fileMenu.add(loadRomItem);
+            }
+
+            JMenuItem prefsItem = new JMenuItem(new ShowPrefsAction());
             fileMenu.add(prefsItem);
+
+            JMenuItem selectMachineItem = new JMenuItem(new SelectMachineAction());
             fileMenu.add(selectMachineItem);
+
+            JMenuItem quitItem = new JMenuItem(new QuitAction());
             fileMenu.add(quitItem);
 
             add(fileMenu);

src/main/java/com/loomcom/symon/machines/Machine.java

@@ -56,5 +56,6 @@ public interface Machine {
     public int getRomSize();
     
     public int getMemorySize();
-    
+
+    String getName();
 }

src/main/java/com/loomcom/symon/machines/MulticompMachine.java

@@ -147,5 +147,10 @@ public class MulticompMachine implements Machine {
     public int getMemorySize() {
         return MEMORY_SIZE;
     }
-    
+
+    @Override
+    public String getName() {
+        return "Multicomp";
+    }
+
 }

src/main/java/com/loomcom/symon/machines/SimpleMachine.java

@@ -0,0 +1,93 @@
+package com.loomcom.symon.machines;
+
+import com.loomcom.symon.Bus;
+import com.loomcom.symon.Cpu;
+import com.loomcom.symon.devices.Acia;
+import com.loomcom.symon.devices.Crtc;
+import com.loomcom.symon.devices.Memory;
+import com.loomcom.symon.devices.Via;
+import com.loomcom.symon.exceptions.MemoryRangeException;
+
+/**
+ * A SimpleMachine is the simplest 6502 implementation possible - it
+ * consists solely of RAM and a CPU. This machine is primarily useful
+ * for running 6502 functional tests or debugging by hand.
+ */
+public class SimpleMachine implements Machine {
+
+    private static final int BUS_BOTTOM = 0x0000;
+    private static final int BUS_TOP    = 0xffff;
+
+    private final Bus bus;
+    private final Memory ram;
+    private final Cpu cpu;
+
+    public SimpleMachine() throws MemoryRangeException {
+        this.bus = new Bus(BUS_BOTTOM, BUS_TOP);
+        this.ram = new Memory(BUS_BOTTOM, BUS_TOP, false);
+        this.cpu = new Cpu();
+
+        bus.addCpu(cpu);
+        bus.addDevice(ram);
+    }
+
+    @Override
+    public Bus getBus() {
+        return bus;
+    }
+
+    @Override
+    public Cpu getCpu() {
+        return cpu;
+    }
+
+    @Override
+    public Memory getRam() {
+        return ram;
+    }
+
+    @Override
+    public Acia getAcia() {
+        return null;
+    }
+
+    @Override
+    public Via getVia() {
+        return null;
+    }
+
+    @Override
+    public Crtc getCrtc() {
+        return null;
+    }
+
+    @Override
+    public Memory getRom() {
+        return null;
+    }
+
+    @Override
+    public void setRom(Memory rom) throws MemoryRangeException {
+        // No-op
+    }
+
+    @Override
+    public int getRomBase() {
+        return 0;
+    }
+
+    @Override
+    public int getRomSize() {
+        return 0;
+    }
+
+    @Override
+    public int getMemorySize() {
+        return BUS_TOP + 1;
+    }
+
+    @Override
+    public String getName() {
+        return "Simple";
+    }
+}

src/main/java/com/loomcom/symon/machines/SymonMachine.java

@@ -160,8 +160,11 @@ public class SymonMachine implements Machine {
     public int getMemorySize() {
         return MEMORY_SIZE;
     }
-    
-    
 
-    
+    @Override
+    public String getName() {
+        return "Symon";
+    }
+
+
 }