Refactor for Java 1.8

- Clean up and refactor code

- Add 1.8 features

- Clean up IntelliJ inspector warnings

pom.xml

@@ -61,27 +61,6 @@
 
     <build>
         <plugins>
-            <plugin>
-                <artifactId>maven-resources-plugin</artifactId>
-                <version>2.6</version>
-                <executions>
-                    <execution>
-                        <id>copy-resources</id>
-                        <phase>process-resources</phase>
-                        <goals>
-                            <goal>copy-resources</goal>
-                        </goals>
-                        <configuration>
-                            <outputDirectory>${basedir}/target/classes/com/loomcom/symon/ui/images</outputDirectory>
-                            <resources>
-                                <resource>
-                                    <directory>src/main/java/com/loomcom/symon/ui/images</directory>
-                                </resource>
-                            </resources>
-                        </configuration>
-                    </execution>
-                </executions>
-            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-assembly-plugin</artifactId>
@@ -112,8 +91,8 @@
                 <version>3.1</version>
                 <configuration>
                     <compilerArgument>-Xlint:unchecked</compilerArgument>
-                    <source>1.6</source>
+                    <source>1.8</source>
-                    <target>1.6</target>
+                    <target>1.8</target>
                 </configuration>
             </plugin>
 

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

@@ -34,6 +34,7 @@ import java.util.Map;
 
 import java.util.SortedSet;
 import java.util.TreeSet;
+import java.util.stream.Collectors;
 
 /**
  * The Bus ties the whole thing together, man.
@@ -62,7 +63,7 @@ public class Bus {
     }
 
     public Bus(int startAddress, int endAddress) {
-        this.deviceMap = new HashMap<Integer, SortedSet<Device>>();
+        this.deviceMap = new HashMap<>();
         this.startAddress = startAddress;
         this.endAddress = endAddress;
     }
@@ -92,24 +93,26 @@ public class Bus {
     /**
      * Add a device to the bus.
      *
-     * @param device
+     * @param device Device to add
-     * @param priority
+     * @param priority Bus prioirity.
      * @throws MemoryRangeException
      */
     public void addDevice(Device device, int priority) throws MemoryRangeException {
         
         MemoryRange range = device.getMemoryRange();
-        if(range.startAddress() < this.startAddress || range.startAddress() > this.endAddress) {
+
+        if (range.startAddress() < this.startAddress || range.startAddress() > this.endAddress) {
             throw new MemoryRangeException("start address of device " + device.getName() + " does not fall within the address range of the bus");
         }
-        if(range.endAddress() < this.startAddress || range.endAddress() > this.endAddress) {
+
+        if (range.endAddress() < this.startAddress || range.endAddress() > this.endAddress) {
             throw new MemoryRangeException("end address of device " + device.getName() + " does not fall within the address range of the bus");
         }
 
-        
         SortedSet<Device> deviceSet = deviceMap.get(priority);
-        if(deviceSet == null) {
+
-            deviceSet = new TreeSet<Device>();
+        if (deviceSet == null) {
+            deviceSet = new TreeSet<>();
             deviceMap.put(priority, deviceSet);
         }
         
@@ -121,7 +124,7 @@ public class Bus {
     /**
      * Add a device to the bus. Throws a MemoryRangeException if the device overlaps with any others.
      *
-     * @param device
+     * @param device Device to add
      * @throws MemoryRangeException
      */
     public void addDevice(Device device) throws MemoryRangeException {
@@ -132,7 +135,7 @@ public class Bus {
     /**
      * Remove a device from the bus.
      *
-     * @param device
+     * @param device Device to remove
      */
     public void removeDevice(Device device) {
         for(SortedSet<Device> deviceSet : deviceMap.values()) {
@@ -214,16 +217,14 @@ public class Bus {
 
     public SortedSet<Device> getDevices() {
         // create an ordered set of devices, ordered by device priorities
-        SortedSet<Device> devices = new TreeSet<Device>();
+        SortedSet<Device> devices = new TreeSet<>();
         
-        List<Integer> priorities = new ArrayList<Integer>(deviceMap.keySet());
+        List<Integer> priorities = new ArrayList<>(deviceMap.keySet());
         Collections.sort(priorities);
         
         for(int priority : priorities) {
             SortedSet<Device> deviceSet = deviceMap.get(priority);
-            for(Device device : deviceSet) {
+            devices.addAll(deviceSet.stream().collect(Collectors.toList()));
-                devices.add(device);
-            }
         }
         
         return devices;

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

@@ -59,7 +59,7 @@ public class Cpu implements InstructionTable {
     public static final int IRQ_VECTOR_H = 0xffff;
 
     /* Simulated behavior */
-    private static CpuBehavior behavior;
+    private CpuBehavior behavior;
 
     /* The Bus */
     private Bus bus;
@@ -67,16 +67,6 @@ public class Cpu implements InstructionTable {
     /* The CPU state */
     private static final CpuState state = new CpuState();
 
-    /* Scratch space for addressing mode and effective address
-     * calculations */
-    private int irAddressMode; // Bits 3-5 of IR:  [ | | |X|X|X| | ]
-    private int irOpMode;      // Bits 6-7 of IR:  [ | | | | | |X|X]
-    private int effectiveAddress;
-
-    /* Internal scratch space */
-    private int lo = 0, hi = 0;  // Used in address calculation
-    private int tmp; // Temporary storage
-    
     /* start time of op execution, needed for speed simulation */
     private long opBeginTime;
 
@@ -109,10 +99,6 @@ public class Cpu implements InstructionTable {
         this.behavior = behavior;
     }
 
-    public CpuBehavior getBehavior() {
-        return behavior;
-    }
-
     /**
      * Reset the CPU to known initial values.
      */
@@ -177,8 +163,8 @@ public class Cpu implements InstructionTable {
 
         // Fetch memory location for this instruction.
         state.ir = bus.read(state.pc);
-        irAddressMode = (state.ir >> 2) & 0x07;
+        int irAddressMode = (state.ir >> 2) & 0x07;  // Bits 3-5 of IR:  [ | | |X|X|X| | ]
-        irOpMode = state.ir & 0x03;
+        int irOpMode = state.ir & 0x03;              // Bits 6-7 of IR:  [ | | | | | |X|X]
 
         incrementPC();
 
@@ -195,7 +181,8 @@ public class Cpu implements InstructionTable {
         state.stepCounter++;
 
         // Get the data from the effective address (if any)
-        effectiveAddress = 0;
+        int effectiveAddress = 0;
+        int tmp; // Temporary storage
 
         switch (irOpMode) {
             case 0:
@@ -299,8 +286,8 @@ public class Cpu implements InstructionTable {
                 break;
             case 0x40: // RTI - Return from Interrupt - Implied
                 setProcessorStatus(stackPop());
-                lo = stackPop();
+                int lo = stackPop();
-                hi = stackPop();
+                int hi = stackPop();
                 setProgramCounter(address(lo, hi));
                 break;
             case 0x48: // PHA - Push Accumulator - Implied
@@ -787,7 +774,7 @@ public class Cpu implements InstructionTable {
      *
      * @param acc     The current value of the accumulator
      * @param operand The operand
-     * @return
+     * @return The sum of the accumulator and the operand
      */
     private int adc(int acc, int operand) {
         int result = (operand & 0xff) + (acc & 0xff) + getCarryBit();
@@ -1455,20 +1442,18 @@ public class Cpu implements InstructionTable {
          */
         public String toTraceEvent() {
             String opcode = disassembleLastOp();
-            StringBuilder sb = new StringBuilder(getInstructionByteStatus());
+            return getInstructionByteStatus() + "  " +
-            sb.append("  ");
+                    String.format("%-14s", opcode) +
-            sb.append(String.format("%-14s", opcode));
+                    "A:" + HexUtil.byteToHex(a) + " " +
-            sb.append("A:" + HexUtil.byteToHex(a) + " ");
+                    "X:" + HexUtil.byteToHex(x) + " " +
-            sb.append("X:" + HexUtil.byteToHex(x) + " ");
+                    "Y:" + HexUtil.byteToHex(y) + " " +
-            sb.append("Y:" + HexUtil.byteToHex(y) + " ");
+                    "F:" + HexUtil.byteToHex(getStatusFlag()) + " " +
-            sb.append("F:" + HexUtil.byteToHex(getStatusFlag()) + " ");
+                    "S:1" + HexUtil.byteToHex(sp) + " " +
-            sb.append("S:1" + HexUtil.byteToHex(sp) + " ");
+                    getProcessorStatusString() + "\n";
-            sb.append(getProcessorStatusString() + "\n");
-            return sb.toString();
         }
 
         /**
-         * @returns The value of the Process Status Register, as a byte.
+         * @return The value of the Process Status Register, as a byte.
          */
         public int getStatusFlag() {
             int status = 0x20;
@@ -1533,35 +1518,35 @@ public class Cpu implements InstructionTable {
 
             switch (instructionModes[ir]) {
                 case ABS:
-                    sb.append(" $" + HexUtil.wordToHex(address(args[0], args[1])));
+                    sb.append(" $").append(HexUtil.wordToHex(address(args[0], args[1])));
                     break;
                 case ABX:
-                    sb.append(" $" + HexUtil.wordToHex(address(args[0], args[1])) + ",X");
+                    sb.append(" $").append(HexUtil.wordToHex(address(args[0], args[1]))).append(",X");
                     break;
                 case ABY:
-                    sb.append(" $" + HexUtil.wordToHex(address(args[0], args[1])) + ",Y");
+                    sb.append(" $").append(HexUtil.wordToHex(address(args[0], args[1]))).append(",Y");
                     break;
                 case IMM:
-                    sb.append(" #$" + HexUtil.byteToHex(args[0]));
+                    sb.append(" #$").append(HexUtil.byteToHex(args[0]));
                     break;
                 case IND:
-                    sb.append(" ($" + HexUtil.wordToHex(address(args[0], args[1])) + ")");
+                    sb.append(" ($").append(HexUtil.wordToHex(address(args[0], args[1]))).append(")");
                     break;
                 case XIN:
-                    sb.append(" ($" + HexUtil.byteToHex(args[0]) + ",X)");
+                    sb.append(" ($").append(HexUtil.byteToHex(args[0])).append(",X)");
                     break;
                 case INY:
-                    sb.append(" ($" + HexUtil.byteToHex(args[0]) + "),Y");
+                    sb.append(" ($").append(HexUtil.byteToHex(args[0])).append("),Y");
                     break;
                 case REL:
                 case ZPG:
-                    sb.append(" $" + HexUtil.byteToHex(args[0]));
+                    sb.append(" $").append(HexUtil.byteToHex(args[0]));
                     break;
                 case ZPX:
-                    sb.append(" $" + HexUtil.byteToHex(args[0]) + ",X");
+                    sb.append(" $").append(HexUtil.byteToHex(args[0])).append(",X");
                     break;
                 case ZPY:
-                    sb.append(" $" + HexUtil.byteToHex(args[0]) + ",Y");
+                    sb.append(" $").append(HexUtil.byteToHex(args[0])).append(",Y");
                     break;
             }
 
@@ -1594,17 +1579,15 @@ public class Cpu implements InstructionTable {
          * @return A string representing the current status register state.
          */
         public String getProcessorStatusString() {
-            StringBuilder sb = new StringBuilder("[");
+            return "[" + (negativeFlag ? 'N' : '.') +
-            sb.append(negativeFlag ? 'N' : '.');    // Bit 7
+                    (overflowFlag ? 'V' : '.') +
-            sb.append(overflowFlag ? 'V' : '.');    // Bit 6
+                    "-" +
-            sb.append("-");                         // Bit 5 (always 1)
+                    (breakFlag ? 'B' : '.') +
-            sb.append(breakFlag ? 'B' : '.');       // Bit 4
+                    (decimalModeFlag ? 'D' : '.') +
-            sb.append(decimalModeFlag ? 'D' : '.'); // Bit 3
+                    (irqDisableFlag ? 'I' : '.') +
-            sb.append(irqDisableFlag ? 'I' : '.');  // Bit 2
+                    (zeroFlag ? 'Z' : '.') +
-            sb.append(zeroFlag ? 'Z' : '.');        // Bit 1
+                    (carryFlag ? 'C' : '.') +
-            sb.append(carryFlag ? 'C' : '.');       // Bit 0
+                    "]";
-            sb.append("]");
-            return sb.toString();
         }
     }
 }

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

@@ -31,7 +31,7 @@ public interface InstructionTable {
      *
      * TODO: As of version 0.6, this is still not used! All CPUs are "idealized" NMOS 6502 only.
      */
-    public enum CpuBehavior {
+    enum CpuBehavior {
         /**
          * The earliest NMOS 6502 includes a bug that causes the ROR instruction
          * to behave like an ASL that does not affect the carry bit. This version
@@ -65,7 +65,7 @@ public interface InstructionTable {
     /**
      * Enumeration of Addressing Modes.
      */
-    public enum Mode {
+    enum Mode {
         ACC {
             public String toString() {
                 return "Accumulator";
@@ -156,7 +156,7 @@ public interface InstructionTable {
     /**
      * Instruction opcode names.
      */
-    public static final String[] opcodeNames = {
+    String[] opcodeNames = {
         "BRK", "ORA",  null,  null,  null, "ORA", "ASL",  null,
         "PHP", "ORA", "ASL",  null,  null, "ORA", "ASL",  null,
         "BPL", "ORA",  null,  null,  null, "ORA", "ASL",  null,
@@ -194,7 +194,7 @@ public interface InstructionTable {
     /**
      * Instruction addressing modes.
      */
-    public static final Mode[] instructionModes = {
+    Mode[] instructionModes = {
         Mode.IMP, Mode.XIN, Mode.NUL, Mode.NUL,   // 0x00-0x03
         Mode.NUL, Mode.ZPG, Mode.ZPG, Mode.NUL,   // 0x04-0x07
         Mode.IMP, Mode.IMM, Mode.ACC, Mode.NUL,   // 0x08-0x0b
@@ -265,7 +265,7 @@ public interface InstructionTable {
     /**
      * Size, in bytes, required for each instruction.
      */
-    public static final int[] instructionSizes = {
+    int[] instructionSizes = {
         1, 2, 0, 0, 0, 2, 2, 0, 1, 2, 1, 0, 0, 3, 3, 0,
         2, 2, 0, 0, 0, 2, 2, 0, 1, 3, 0, 0, 0, 3, 3, 0,
         3, 2, 0, 0, 2, 2, 2, 0, 1, 2, 1, 0, 3, 3, 3, 0,
@@ -287,7 +287,7 @@ public interface InstructionTable {
     /**
      * Number of clock cycles required for each instruction
      */
-    public static final int[] instructionClocks = {
+    int[] instructionClocks = {
         7, 6, 0, 0, 0, 3, 5, 0, 3, 2, 2, 0, 0, 4, 6, 0,
         2, 5, 0, 0, 0, 4, 6, 0, 2, 4, 0, 0, 0, 4, 7, 0,
         6, 6, 0, 0, 3, 3, 5, 0, 4, 2, 2, 0, 4, 4, 6, 0,

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

@@ -39,7 +39,7 @@ public class Main {
      * Main entry point to the simulator. Creates a simulator and shows the main
      * window.
      *
-     * @param args
+     * @param args Program arguments
      */
     public static void main(String args[]) throws Exception {
         
@@ -48,12 +48,16 @@ public class Main {
             String arg = args[i].toLowerCase(Locale.ENGLISH);
             if(arg.equals("-machine") && (i+1) < args.length) {
                 String machine = args[i+1].trim().toLowerCase(Locale.ENGLISH);
-                if(machine.equals("symon")) {
+                switch (machine) {
-                    machineClass = SymonMachine.class;
+                    case "symon":
-                } else if(machine.equals("multicomp")) {
+                        machineClass = SymonMachine.class;
-                    machineClass = MulticompMachine.class;
+                        break;
-                } else if (machine.equals("simple")) {
+                    case "multicomp":
-                    machineClass = SimpleMachine.class;
+                        machineClass = MulticompMachine.class;
+                        break;
+                    case "simple":
+                        machineClass = SimpleMachine.class;
+                        break;
                 }
             }
         }
@@ -82,15 +86,13 @@ public class Main {
         
             final Simulator simulator = new Simulator(machineClass);
         
-            SwingUtilities.invokeLater(new Runnable() {
+            SwingUtilities.invokeLater(() -> {
-                public void run() {
+                try {
-                    try {
+                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
-                        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
+                    // Create the main UI window
-                        // Create the main UI window
+                    simulator.createAndShowUi();
-                        simulator.createAndShowUi();
+                } catch (Exception e) {
-                    } catch (Exception e) {
+                    e.printStackTrace();
-                        e.printStackTrace();
-                    }
                 }
             });
         

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

@@ -34,77 +34,78 @@ import com.loomcom.symon.exceptions.*;
  */
 public class MemoryRange implements Comparable<MemoryRange> {
 
-  /** The starting address of the memory range. */
+    /**
-  public int startAddress;
+     * The starting address of the memory range.
-  /** The ending address of the memory range. */
+     */
-  public int endAddress;
+    public int startAddress;
+    /**
+     * The ending address of the memory range.
+     */
+    public int endAddress;
 
-  public MemoryRange(int startAddress, int endAddress)
+    public MemoryRange(int startAddress, int endAddress)
-		throws MemoryRangeException {
+            throws MemoryRangeException {
-    if (startAddress < 0 || endAddress < 0) {
+        if (startAddress < 0 || endAddress < 0) {
-      throw new MemoryRangeException("Addresses cannot be less than 0.");
+            throw new MemoryRangeException("Addresses cannot be less than 0.");
+        }
+        if (startAddress >= endAddress) {
+            throw new MemoryRangeException("End address must be greater " +
+                    "than start address.");
+        }
+        this.startAddress = startAddress;
+        this.endAddress = endAddress;
     }
-    if (startAddress >= endAddress) {
+
-      throw new MemoryRangeException("End address must be greater " +
+    /**
-                                     "than start address.");
+     * @return the starting address.
+     */
+    public int startAddress() {
+        return startAddress;
     }
-    this.startAddress = startAddress;
-    this.endAddress = endAddress;
-  }
 
-  /**
+    /**
-   * @returns the starting address.
+     * @return the ending address.
-   */
+     */
-  public int startAddress() {
+    public int endAddress() {
-    return startAddress;
+        return endAddress;
-  }
-
-  /**
-   * @returns the ending address.
-   */
-  public int endAddress() {
-    return endAddress;
-  }
-
-  /**
-   * Checks for address inclusion in the range.
-   *
-   * @returns true if the address is included within this range,
-   *          false otherwise.
-   */
-  public boolean includes(int address) {
-    return (address <= endAddress &&
-            address >= startAddress);
-  }
-
-  /**
-   * Checks for overlapping memory ranges.
-   *
-   * @returns true if this range overlaps in any way with the other.
-   */
-  public boolean overlaps(MemoryRange other) {
-    return (this.includes(other.startAddress()) ||
-            other.includes(this.startAddress()));
-  }
-
-  // Implementation of Comparable interface
-  public int compareTo(MemoryRange other) {
-    if (other == null) {
-      throw new NullPointerException("Cannot compare to null.");
     }
-    if (this == other) {
-      return 0;
-    }
-    Integer thisStartAddr = new Integer(this.startAddress());
-    Integer thatStartAddr = new Integer(other.startAddress());
-    return thisStartAddr.compareTo(thatStartAddr);
-  }
 
-  public String toString() {
+    /**
-    StringBuffer desc = new StringBuffer("@");
+     * Checks for address inclusion in the range.
-    desc.append(String.format("0x%04x", startAddress));
+     *
-    desc.append("-");
+     * @return true if the address is included within this range,
-    desc.append(String.format("0x%04x", endAddress));
+     * false otherwise.
-    return desc.toString();
+     */
-  }
+    public boolean includes(int address) {
+        return (address <= endAddress &&
+                address >= startAddress);
+    }
+
+    /**
+     * Checks for overlapping memory ranges.
+     *
+     * @return true if this range overlaps in any way with the other.
+     */
+    public boolean overlaps(MemoryRange other) {
+        return (this.includes(other.startAddress()) ||
+                other.includes(this.startAddress()));
+    }
+
+    // Implementation of Comparable interface
+    public int compareTo(MemoryRange other) {
+        if (other == null) {
+            throw new NullPointerException("Cannot compare to null.");
+        }
+        if (this == other) {
+            return 0;
+        }
+        Integer thisStartAddr = this.startAddress();
+        Integer thatStartAddr = other.startAddress();
+        return thisStartAddr.compareTo(thatStartAddr);
+    }
+
+    public String toString() {
+        return "@" + String.format("0x%04x", startAddress) + "-" +
+                String.format("0x%04x", endAddress);
+    }
 }

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

@@ -27,15 +27,15 @@ import javax.swing.*;
 
 public interface Preferences {
 
-    public static final int DEFAULT_PROGRAM_LOAD_ADDRESS = 0x0300;
+    int DEFAULT_PROGRAM_LOAD_ADDRESS = 0x0300;
 
-    public static final boolean DEFAULT_HALT_ON_BREAK = true;
+    boolean DEFAULT_HALT_ON_BREAK = true;
 
-    public JDialog getDialog();
+    JDialog getDialog();
 
-    public int getProgramStartAddress();
+    int getProgramStartAddress();
 
-    public boolean getHaltOnBreak();
+    boolean getHaltOnBreak();
 
-    public void updateUi();
+    void updateUi();
 }

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

@@ -73,7 +73,7 @@ public class Simulator {
 
     // Number of CPU steps between CRT repaints.
     // TODO: Dynamically refresh the value at runtime based on performance figures to reach ~ 30fps.
-    private long stepsBetweenCrtcRefreshes = 2500;
+    private static final long STEPS_BETWEEN_CRTC_REFRESHES = 2500;
 
     // A counter to keep track of the number of UI updates that have been
     // requested
@@ -93,14 +93,14 @@ public class Simulator {
     /**
      * The Trace Window shows the most recent 50,000 CPU states.
      */
-    private TraceLog traceLog;
+    private final TraceLog traceLog;
 
     /**
      * The Memory Window shows the contents of one page of memory.
      */
-    private MemoryWindow memoryWindow;
+    private final MemoryWindow memoryWindow;
 
-    private VideoWindow videoWindow;
+    private final VideoWindow videoWindow;
 
     private SimulatorMenu menuBar;
 
@@ -110,8 +110,6 @@ public class Simulator {
 
     private JButton runStopButton;
     private JButton stepButton;
-    private JButton softResetButton;
-    private JButton hardResetButton;
     private JComboBox<String> stepCountBox;
 
     private JFileChooser      fileChooser;
@@ -119,7 +117,7 @@ public class Simulator {
 
     private final Object commandMonitorObject = new Object();
     private MAIN_CMD command = MAIN_CMD.NONE;
-    public static enum MAIN_CMD  {
+    public enum MAIN_CMD  {
         NONE,
         SELECTMACHINE
     }
@@ -131,6 +129,15 @@ public class Simulator {
 
     public Simulator(Class machineClass) throws Exception {
         this.machine = (Machine) machineClass.getConstructors()[0].newInstance();
+
+        // Initialize final fields in the constructor.
+        this.traceLog = new TraceLog();
+        this.memoryWindow = new MemoryWindow(machine.getBus());
+        if(machine.getCrtc() != null) {
+            videoWindow = new VideoWindow(machine.getCrtc(), 2, 2);
+        } else {
+            videoWindow = null;
+        }
     }
 
     /**
@@ -143,7 +150,7 @@ public class Simulator {
         mainWindow.getContentPane().setLayout(new BorderLayout());
 
         // UI components used for I/O.
-        this.console = new com.loomcom.symon.ui.Console(80, 25, DEFAULT_FONT);
+        this.console = new com.loomcom.symon.ui.Console(80, 25, DEFAULT_FONT, false);
         this.statusPane = new StatusPanel(machine);
 
         console.setBorderWidth(CONSOLE_BORDER_WIDTH);
@@ -162,19 +169,17 @@ public class Simulator {
 
         runStopButton = new JButton("Run");
         stepButton = new JButton("Step");
-        softResetButton = new JButton("Soft Reset");
+        JButton softResetButton = new JButton("Soft Reset");
-        hardResetButton = new JButton("Hard Reset");
+        JButton hardResetButton = new JButton("Hard Reset");
 
-        stepCountBox = new JComboBox<String>(STEPS);
+        stepCountBox = new JComboBox<>(STEPS);
-        stepCountBox.addActionListener(new ActionListener() {
+        stepCountBox.addActionListener(actionEvent -> {
-            public void actionPerformed(ActionEvent actionEvent) {
+            try {
-                try {
+                JComboBox cb = (JComboBox) actionEvent.getSource();
-                    JComboBox cb = (JComboBox) actionEvent.getSource();
+                stepsPerClick = Integer.parseInt((String) cb.getSelectedItem());
-                    stepsPerClick = Integer.parseInt((String) cb.getSelectedItem());
+            } catch (NumberFormatException ex) {
-                } catch (NumberFormatException ex) {
+                stepsPerClick = 1;
-                    stepsPerClick = 1;
+                stepCountBox.setSelectedIndex(0);
-                    stepCountBox.setSelectedIndex(0);
-                }
             }
         });
 
@@ -194,48 +199,27 @@ public class Simulator {
         // Bottom - buttons.
         mainWindow.getContentPane().add(buttonContainer, BorderLayout.PAGE_END);
 
-        runStopButton.addActionListener(new ActionListener() {
+        runStopButton.addActionListener(actionEvent -> {
-            public void actionPerformed(ActionEvent actionEvent) {
+            if (runLoop != null && runLoop.isRunning()) {
-                if (runLoop != null && runLoop.isRunning()) {
+                handleStop();
-                    handleStop();
+            } else {
-                } else {
+                handleStart();
-                    handleStart();
-                }
             }
         });
 
-        stepButton.addActionListener(new ActionListener() {
+        stepButton.addActionListener(actionEvent -> handleStep(stepsPerClick));
-            public void actionPerformed(ActionEvent actionEvent) {
+
-                handleStep(stepsPerClick);
+        softResetButton.addActionListener(actionEvent -> {
-            }
+            // If this was a CTRL-click, do a hard reset.
+            handleReset(false);
         });
 
-        softResetButton.addActionListener(new ActionListener() {
+        hardResetButton.addActionListener(actionEvent -> {
-            public void actionPerformed(ActionEvent actionEvent) {
+            // If this was a CTRL-click, do a hard reset.
-                // If this was a CTRL-click, do a hard reset.
+            handleReset(true);
-                handleReset(false);
-            }
         });
 
-        hardResetButton.addActionListener(new ActionListener() {
+        mainWindow.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
-            public void actionPerformed(ActionEvent actionEvent) {
-                // If this was a CTRL-click, do a hard reset.
-                handleReset(true);
-            }
-        });
-
-        // Prepare the log window
-        traceLog = new TraceLog();
-
-        // Prepare the memory window
-        memoryWindow = new MemoryWindow(machine.getBus());
-
-        // Composite Video and 6545 CRTC
-        if(machine.getCrtc() != null) {
-            videoWindow = new VideoWindow(machine.getCrtc(), 2, 2);
-        }
-
-        mainWindow.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 
         // The Menu. This comes last, because it relies on other components having
         // already been initialized.
@@ -348,7 +332,7 @@ public class Simulator {
             logger.error("Console type-ahead buffer underrun!");
         }
 
-        if (videoWindow != null && stepsSinceLastCrtcRefresh++ > stepsBetweenCrtcRefreshes) {
+        if (videoWindow != null && stepsSinceLastCrtcRefresh++ > STEPS_BETWEEN_CRTC_REFRESHES) {
             stepsSinceLastCrtcRefresh = 0;
             if (videoWindow.isVisible()) {
                 videoWindow.repaint();
@@ -405,15 +389,13 @@ public class Simulator {
             logger.info("Starting main run loop.");
             isRunning = true;
 
-            SwingUtilities.invokeLater(new Runnable() {
+            SwingUtilities.invokeLater(() -> {
-                public void run() {
+                // Don't allow step while the simulator is running
-                    // Don't allow step while the simulator is running
+                stepButton.setEnabled(false);
-                    stepButton.setEnabled(false);
+                stepCountBox.setEnabled(false);
-                    stepCountBox.setEnabled(false);
+                menuBar.simulatorDidStart();
-                    menuBar.simulatorDidStart();
+                // Toggle the state of the run button
-                    // Toggle the state of the run button
+                runStopButton.setText("Stop");
-                    runStopButton.setText("Stop");
-                }
             });
 
             try {
@@ -424,19 +406,17 @@ public class Simulator {
                 logger.error("Exception in main simulator run thread. Exiting run.", ex);
             }
 
-            SwingUtilities.invokeLater(new Runnable() {
+            SwingUtilities.invokeLater(() -> {
-                public void run() {
+                statusPane.updateState();
-                    statusPane.updateState();
+                memoryWindow.updateState();
-                    memoryWindow.updateState();
+                runStopButton.setText("Run");
-                    runStopButton.setText("Run");
+                stepButton.setEnabled(true);
-                    stepButton.setEnabled(true);
+                stepCountBox.setEnabled(true);
-                    stepCountBox.setEnabled(true);
+                if (traceLog.isVisible()) {
-                    if (traceLog.isVisible()) {
+                    traceLog.refresh();
-                        traceLog.refresh();
-                    }
-                    menuBar.simulatorDidStop();
-                    traceLog.simulatorDidStop();
                 }
+                menuBar.simulatorDidStop();
+                traceLog.simulatorDidStop();
             });
 
             isRunning = false;
@@ -482,11 +462,7 @@ public class Simulator {
                                 program[i++] = dis.readByte();
                             }
 
-                            SwingUtilities.invokeLater(new Runnable() {
+                            SwingUtilities.invokeLater(() -> console.reset());
-                                public void run() {
-                                    console.reset();
-                                }
-                            });
 
                             // Now load the program at the starting address.
                             loadProgram(program, preferences.getProgramStartAddress());
@@ -625,11 +601,9 @@ public class Simulator {
         }
 
         public void actionPerformed(ActionEvent actionEvent) {
-            SwingUtilities.invokeLater(new Runnable() {
+            SwingUtilities.invokeLater(() -> {
-                public void run() {
+                console.setFont(new Font("Monospaced", Font.PLAIN, size));
-                    console.setFont(new Font("Monospaced", Font.PLAIN, size));
+                mainWindow.pack();
-                    mainWindow.pack();
-                }
             });
         }
     }
@@ -812,14 +786,12 @@ public class Simulator {
 
     private void updateVisibleState() {
         // Immediately update the UI.
-        SwingUtilities.invokeLater(new Runnable() {
+        SwingUtilities.invokeLater(() -> {
-            public void run() {
+            // Now update the state
-                // Now update the state
+            statusPane.updateState();
-                statusPane.updateState();
+            memoryWindow.updateState();
-                memoryWindow.updateState();
+            if (traceLog.shouldUpdate()) {
-                if (traceLog.shouldUpdate()) {
+                traceLog.refresh();
-                    traceLog.refresh();
-                }
             }
         });
     }

src/main/java/com/loomcom/symon/devices/Acia.java

@@ -82,6 +82,7 @@ public abstract class Acia extends Device {
     /**
      * @return The simulated baud rate in bps.
      */
+    @SuppressWarnings("unused")
     public int getBaudRate() {
         return baudRate;
     }
@@ -153,6 +154,7 @@ public abstract class Acia extends Device {
     /**
      * @return true if there is character data in the RX register.
      */
+    @SuppressWarnings("unused")
     public boolean hasRxChar() {
         return rxFull;
     }

src/main/java/com/loomcom/symon/devices/Acia6551.java

@@ -26,7 +26,6 @@ package com.loomcom.symon.devices;
 import com.loomcom.symon.exceptions.MemoryAccessException;
 import com.loomcom.symon.exceptions.MemoryRangeException;
 
-
 /**
  * This is a simulation of the MOS 6551 ACIA, with limited
  * functionality.  Interrupts are not supported.
@@ -45,7 +44,6 @@ public class Acia6551 extends Acia {
     static final int CMND_REG = 2;
     static final int CTRL_REG = 3;
 
-
     /**
      * Registers. These are ignored in the current implementation.
      */
@@ -106,7 +104,7 @@ public class Acia6551 extends Acia {
     /**
      * Set the control register and associated state.
      *
-     * @param data
+     * @param data Data to write into the control register
      */
     private void setControlRegister(int data) {
         controlRegister = data;

src/main/java/com/loomcom/symon/devices/Acia6850.java

@@ -41,20 +41,12 @@ public class Acia6850 extends Acia {
 
     public static final int ACIA_SIZE = 2;
 
-
     static final int STAT_REG = 0;	// read-only
     static final int CTRL_REG = 0;	// write-only
 	
     static final int RX_REG = 1;	// read-only
     static final int TX_REG = 1;	// write-only
 
-    
-    /**
-     * Registers. These are ignored in the current implementation.
-     */
-    private int commandRegister;
-
-
     public Acia6850(int address) throws MemoryRangeException {
         super(address, ACIA_SIZE, "ACIA6850");
         setBaudRate(2400);
@@ -88,17 +80,15 @@ public class Acia6850 extends Acia {
     }
     
     private void setCommandRegister(int data) {
-        commandRegister = data;
-		
         // Bits 0 & 1 control the master reset
-        if((commandRegister & 0x01) != 0 && (commandRegister & 0x02) != 0) {
+        if((data & 0x01) != 0 && (data & 0x02) != 0) {
             reset();
         }
 
         // Bit 7 controls receiver IRQ behavior
-        receiveIrqEnabled = (commandRegister & 0x80) != 0;
+        receiveIrqEnabled = (data & 0x80) != 0;
         // Bits 5 & 6 controls transmit IRQ behavior
-        transmitIrqEnabled = (commandRegister & 0x20) != 0 && (commandRegister & 0x40) == 0;
+        transmitIrqEnabled = (data & 0x20) != 0 && (data & 0x40) == 0;
     }
 
 

src/main/java/com/loomcom/symon/devices/Crtc.java

@@ -27,17 +27,11 @@ import com.loomcom.symon.exceptions.MemoryAccessException;
 import com.loomcom.symon.exceptions.MemoryRangeException;
 
 import java.io.IOException;
-import java.util.logging.Logger;
-
 
 /**
  * Simulation of a 6545 CRTC and virtual CRT output.
  */
 public class Crtc extends Device {
-
-    private static final Logger logger = Logger.getLogger(Crtc.class.getName());
-
-
     // Memory locations in the CRTC address space
     public static final int REGISTER_SELECT          = 0;
     public static final int REGISTER_RW              = 1;

src/main/java/com/loomcom/symon/devices/Device.java

@@ -62,16 +62,11 @@ public abstract class Device implements Comparable<Device> {
      */
     private Set<DeviceChangeListener> deviceChangeListeners;
 
-    public Device(int startAddress, int endAddress, String name)
+    public Device(int startAddress, int endAddress, String name) throws MemoryRangeException {
-            throws MemoryRangeException {
         this.memoryRange = new MemoryRange(startAddress, endAddress);
         this.size = endAddress - startAddress + 1;
         this.name = name;
-        this.deviceChangeListeners = new HashSet<DeviceChangeListener>();
+        this.deviceChangeListeners = new HashSet<>();
-    }
-
-    public Device(int startAddress, int endAddress) throws MemoryRangeException {
-        this(startAddress, endAddress, null);
     }
 
     /* Methods required to be implemented by inheriting classes. */
@@ -97,6 +92,7 @@ public abstract class Device implements Comparable<Device> {
         return memoryRange.endAddress();
     }
 
+    @SuppressWarnings("unused")
     public int startAddress() {
         return memoryRange.startAddress();
     }
@@ -105,6 +101,7 @@ public abstract class Device implements Comparable<Device> {
         return name;
     }
 
+    @SuppressWarnings("unused")
     public void setName(String name) {
         this.name = name;
     }
@@ -118,9 +115,7 @@ public abstract class Device implements Comparable<Device> {
     }
 
     public void notifyListeners() {
-        for (DeviceChangeListener l : deviceChangeListeners) {
+        deviceChangeListeners.forEach(DeviceChangeListener::deviceStateChanged);
-            l.deviceStateChanged();
-        }
     }
 
     /**

src/main/java/com/loomcom/symon/devices/DeviceChangeListener.java

@@ -24,5 +24,5 @@
 package com.loomcom.symon.devices;
 
 public interface DeviceChangeListener {
-    public void deviceStateChanged();
+    void deviceStateChanged();
 }

src/main/java/com/loomcom/symon/devices/Memory.java

@@ -28,8 +28,6 @@ import java.util.*;
 
 import com.loomcom.symon.exceptions.*;
 
-import javax.swing.*;
-
 public class Memory extends Device {
 
     private boolean readOnly;
@@ -57,8 +55,7 @@ public class Memory extends Device {
     }
 
     public static Memory makeRAM(int startAddress, int endAddress) throws MemoryRangeException {
-        Memory memory = new Memory(startAddress, endAddress, false);
+        return new Memory(startAddress, endAddress, false);
-        return memory;
     }
 
     public void write(int address, int data) throws MemoryAccessException {
@@ -108,8 +105,4 @@ public class Memory extends Device {
     public String toString() {
         return "Memory: " + getMemoryRange().toString();
     }
-
-    public int[] getDmaAccess() {
-        return mem;
-    }
 }

src/main/java/com/loomcom/symon/devices/SdController.java

@@ -27,6 +27,8 @@ package com.loomcom.symon.devices;
 
 import com.loomcom.symon.exceptions.MemoryAccessException;
 import com.loomcom.symon.exceptions.MemoryRangeException;
+import jdk.nashorn.internal.ir.annotations.Ignore;
+
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
@@ -37,7 +39,6 @@ import java.util.logging.Logger;
 /**
  * Emulation for the SD-card controller of the MULTICOMP system.
  * Neiter comlete nor correct.
- * 
  */
 public class SdController extends Device {
 
@@ -52,8 +53,7 @@ public class SdController extends Device {
     private final static Logger logger = Logger.getLogger(SdController.class.getName());
 
     private File sdImageFile;
-    private int lba0,lba1,lba2;
+    private int lba0, lba1, lba2;
-    private int command;
     private int position;
     private Status status = Status.IDLE;
 
@@ -67,7 +67,7 @@ public class SdController extends Device {
         super(address, address + CONTROLLER_SIZE - 1, "SDCONTROLLER");
 
         sdImageFile = new File("sd.img");
-        if(!sdImageFile.exists()) {
+        if (!sdImageFile.exists()) {
             sdImageFile = null;
             logger.log(Level.INFO, "Could not find SD card image 'sd.img'");
         }
@@ -76,27 +76,27 @@ public class SdController extends Device {
 
     @Override
     public void write(int address, int data) throws MemoryAccessException {
-        switch(address) {
+        switch (address) {
-            case 0 :
+            case 0:
                 writeData(data);
                 return;
-            case 1 :
+            case 1:
                 writeCommand(data);
                 return;
-            case 2 :
+            case 2:
                 this.lba0 = data;
                 return;
-            case 3 : 
+            case 3:
                 this.lba1 = data;
                 return;
-            case 4 :
+            case 4:
                 this.lba2 = data;
         }
     }
 
     @Override
     public int read(int address) throws MemoryAccessException {
-        switch(address) {
+        switch (address) {
             case 0:
                 return readData();
             case 1:
@@ -117,12 +117,12 @@ public class SdController extends Device {
         this.readPosition = 0;
         computePosition();
 
-        if(sdImageFile != null) {
+        if (sdImageFile != null) {
             try {
                 FileInputStream fis = new FileInputStream(sdImageFile);
                 fis.skip(this.position);
                 int read = fis.read(readBuffer);
-                if(read < SECTOR_SIZE) {
+                if (read < SECTOR_SIZE) {
                     logger.log(Level.WARNING, "not enough data to fill read buffer from SD image file");
                 }
                 fis.close();
@@ -140,13 +140,13 @@ public class SdController extends Device {
 
 
     private int readData() {
-        if(status != Status.READ) {
+        if (status != Status.READ) {
             return 0;
         }
 
         int data = readBuffer[readPosition++];
 
-        if(readPosition >= SECTOR_SIZE) {
+        if (readPosition >= SECTOR_SIZE) {
             this.status = Status.IDLE;
         }
 
@@ -154,14 +154,14 @@ public class SdController extends Device {
     }
 
     private void writeData(int data) {
-        if(status != Status.WRITE) {
+        if (status != Status.WRITE) {
             return;
         }
 
         writeBuffer[writePosition++] = (byte) data;
 
-        if(writePosition >= SECTOR_SIZE) {
+        if (writePosition >= SECTOR_SIZE) {
-            if(sdImageFile != null) {
+            if (sdImageFile != null) {
                 try {
                     RandomAccessFile raf = new RandomAccessFile(sdImageFile, "rw");
                     raf.skipBytes(this.position);
@@ -178,7 +178,7 @@ public class SdController extends Device {
     }
 
     private int readStatus() {
-        switch(this.status) {
+        switch (this.status) {
             case IDLE:
                 return 128;
             case READ:
@@ -191,12 +191,11 @@ public class SdController extends Device {
     }
 
     private void writeCommand(int data) {
-        this.command = data;
+        switch (data) {
-        switch(this.command) {
+            case 0:
-            case 0 :
                 prepareRead();
                 return;
-            case 1 :
+            case 1:
                 prepareWrite();
                 return;
             default:

src/main/java/com/loomcom/symon/devices/Via6522.java

@@ -39,10 +39,6 @@ public class Via6522 extends Pia {
         T2C_L, T2C_H, SR, ACR, PCR, IFR, IER, ORA_H
     }
 
-    // Ports A and B
-    private char[] portData = {0, 0};
-    private char[] portDirections = {0, 0};
-
     public Via6522(int address) throws MemoryRangeException {
         super(address, address + VIA_SIZE - 1, "MOS 6522 VIA");
     }

src/main/java/com/loomcom/symon/exceptions/SymonException.java

@@ -31,7 +31,4 @@ public class SymonException extends Exception {
     public SymonException(String msg) {
         super(msg);
     }
-    public SymonException() {
-        super();
-    }
 }

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

@@ -35,27 +35,27 @@ import com.loomcom.symon.exceptions.MemoryRangeException;
 
 public interface Machine {
     
-    public Bus getBus();
+    Bus getBus();
 
-    public Cpu getCpu();
+    Cpu getCpu();
     
-    public Memory getRam();
+    Memory getRam();
     
-    public Acia getAcia();
+    Acia getAcia();
     
-    public Pia getPia();
+    Pia getPia();
     
-    public Crtc getCrtc();
+    Crtc getCrtc();
     
-    public Memory getRom();
+    Memory getRom();
     
-    public void setRom(Memory rom) throws MemoryRangeException;
+    void setRom(Memory rom) throws MemoryRangeException;
     
-    public int getRomBase();
+    int getRomBase();
     
-    public int getRomSize();
+    int getRomSize();
     
-    public int getMemorySize();
+    int getMemorySize();
 
     String getName();
 }

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

@@ -65,7 +65,6 @@ public class MulticompMachine implements Machine {
     private final Cpu    cpu;
     private final Acia   acia;
     private final Memory ram;
-    private final SdController sdController;
     private       Memory rom;
 
 
@@ -75,12 +74,11 @@ public class MulticompMachine implements Machine {
         this.ram = new Memory(MEMORY_BASE, MEMORY_BASE + MEMORY_SIZE - 1, false);
         this.acia = new Acia6850(ACIA_BASE);
         this.acia.setBaudRate(0);
-        this.sdController = new SdController(SD_BASE);
 
         bus.addCpu(cpu);
         bus.addDevice(ram);
         bus.addDevice(acia, 1);
-        bus.addDevice(sdController, 1);
+        bus.addDevice(new SdController(SD_BASE), 1);
         
         // TODO: Make this configurable, of course.
         File romImage = new File("rom.bin");

src/main/java/com/loomcom/symon/ui/Console.java

@@ -44,21 +44,20 @@ import java.awt.event.MouseListener;
 
 public class Console extends JTerminal implements KeyListener, MouseListener {
 
-    private static final int     DEFAULT_COLUMNS      = 80;
-    private static final int     DEFAULT_ROWS         = 24;
     private static final int     DEFAULT_BORDER_WIDTH = 10;
     // If true, swap CR and LF characters.
     private static final boolean SWAP_CR_AND_LF       = true;
-    // If true, send CRLF (0x0d 0x0a) whenever CR is typed
-    private static final boolean SEND_CR_LF_FOR_CR    = false;
 
+    // If true, send CRLF (0x0d 0x0a) whenever CR is typed
+    private boolean sendCrForLf = false;
     private FifoRingBuffer<Character> typeAheadBuffer;
 
-    public Console(int columns, int rows, Font font) {
+    public Console(int columns, int rows, Font font, boolean sendCrForLf) {
         super(new Vt100TerminalModel(columns, rows), font);
         // A small type-ahead buffer, as might be found in any real
         // VT100-style serial terminal.
-        this.typeAheadBuffer = new FifoRingBuffer<Character>(128);
+        this.typeAheadBuffer = new FifoRingBuffer<>(128);
+        this.sendCrForLf = sendCrForLf;
         setBorderWidth(DEFAULT_BORDER_WIDTH);
         addKeyListener(this);
         addMouseListener(this);
@@ -83,7 +82,7 @@ public class Console extends JTerminal implements KeyListener, MouseListener {
     /**
      * Returns true if a key has been pressed since the last time input was read.
      *
-     * @return
+     * @return true if the type-ahead buffer has data
      */
     public boolean hasInput() {
         return !typeAheadBuffer.isEmpty();
@@ -105,7 +104,7 @@ public class Console extends JTerminal implements KeyListener, MouseListener {
             }
         }
 
-        if (SEND_CR_LF_FOR_CR && keyTyped == 0x0d) {
+        if (sendCrForLf && keyTyped == 0x0d) {
             typeAheadBuffer.push((char) 0x0d);
             typeAheadBuffer.push((char) 0x0a);
         } else {

src/main/java/com/loomcom/symon/ui/MemoryWindow.java

@@ -346,12 +346,8 @@ public class MemoryWindow extends JFrame implements ActionListener {
                     int fullAddress = fullAddress(row, column);
                     int newValue = Integer.parseInt(hexValue, 16) & 0xff;
                     bus.write(fullAddress, newValue);
-                } catch (MemoryAccessException ex) {
+                } catch (MemoryAccessException | NumberFormatException | ClassCastException ex) {
-                    ;
+                    // Intentionally swallow exception
-                } catch (NumberFormatException ex) {
-                    ;
-                } catch (ClassCastException ex) {
-                    ;
                 }
                 fireTableCellUpdated(row, column);
             }

src/main/java/com/loomcom/symon/ui/PreferencesDialog.java

@@ -97,23 +97,19 @@ public class PreferencesDialog extends Observable implements Preferences {
         JButton applyButton = new JButton("Apply");
         JButton cancelButton = new JButton("Cancel");
 
-        cancelButton.addActionListener(new ActionListener() {
+        cancelButton.addActionListener(actionEvent -> {
-            public void actionPerformed(ActionEvent actionEvent) {
+            updateUi();
-                updateUi();
+            dialog.setVisible(false);
-                dialog.setVisible(false);
-            }
         });
 
-        applyButton.addActionListener(new ActionListener() {
+        applyButton.addActionListener(actionEvent -> {
-            public void actionPerformed(ActionEvent actionEvent) {
+            haltOnBreak = haltOnBreakCheckBox.isSelected();
-                haltOnBreak = haltOnBreakCheckBox.isSelected();
+            programLoadAddress = hexToInt(programLoadAddressField.getText());
-                programLoadAddress = hexToInt(programLoadAddressField.getText());
+            updateUi();
-                updateUi();
+            // TODO: Actually check to see if values have changed, don't assume.
-                // TODO: Actually check to see if values have changed, don't assume.
+            setChanged();
-                setChanged();
+            PreferencesDialog.this.notifyObservers();
-                PreferencesDialog.this.notifyObservers();
+            dialog.setVisible(false);
-                dialog.setVisible(false);
-            }
         });
 
         buttonsContainer.add(applyButton);

src/main/java/com/loomcom/symon/ui/StatusPanel.java

@@ -53,7 +53,6 @@ public class StatusPanel extends JPanel {
     private ImageIcon negativeOn;
     private ImageIcon negativeOff;
 
-    private JLabel statusFlagsLabel;
     private JLabel carryFlagLabel;
     private JLabel zeroFlagLabel;
     private JLabel irqDisableFlagLabel;
@@ -69,13 +68,6 @@ public class StatusPanel extends JPanel {
     private JTextField xField;
     private JTextField yField;
 
-    private JLabel opcodeLabel;
-    private JLabel pcLabel;
-    private JLabel spLabel;
-    private JLabel aLabel;
-    private JLabel xLabel;
-    private JLabel yLabel;
-
     private Machine machine;
 
     private static final int EMPTY_BORDER = 10;
@@ -150,13 +142,13 @@ public class StatusPanel extends JPanel {
         statusFlagsPanel.add(carryFlagLabel);
 
         // Create and add register and address labels
-        statusFlagsLabel = makeLabel("Flags");
+        JLabel statusFlagsLabel = makeLabel("Flags");
-        opcodeLabel = makeLabel("Next IR");
+        JLabel opcodeLabel = makeLabel("Next IR");
-        pcLabel = makeLabel("PC");
+        JLabel pcLabel = makeLabel("PC");
-        spLabel = makeLabel("SP");
+        JLabel spLabel = makeLabel("SP");
-        aLabel = makeLabel("A");
+        JLabel aLabel = makeLabel("A");
-        xLabel = makeLabel("X");
+        JLabel xLabel = makeLabel("X");
-        yLabel = makeLabel("Y");
+        JLabel yLabel = makeLabel("Y");
 
         statusFlagsLabel.setToolTipText("6502 Processor Status Flags");
         opcodeLabel.setToolTipText("Instruction Register");
@@ -171,74 +163,59 @@ public class StatusPanel extends JPanel {
         yField = makeTextField(SMALL_TEXT_FIELD_SIZE, true);
 
         // Make fields editable
-        pcField.addActionListener(new ActionListener() {
+        pcField.addActionListener(e -> {
-            @Override
+            try {
-            public void actionPerformed(ActionEvent e) {
+                int newVal = getHexVal(pcField) & 0xffff;
-                try {
+                machine.getCpu().setProgramCounter(newVal);
-                    int newVal = getHexVal(pcField) & 0xffff;
+            } catch (Exception ex) {
-                    machine.getCpu().setProgramCounter(newVal);
+                // Swallow exception
-                } catch (Exception ex) {
-                    // Swallow exception
-                }
-
-                updateState();
             }
+
+            updateState();
         });
 
-        spField.addActionListener(new ActionListener() {
+        spField.addActionListener(e -> {
-            @Override
+            try {
-            public void actionPerformed(ActionEvent e) {
+                int newVal = getHexVal(spField) & 0xff;
-                try {
+                machine.getCpu().setStackPointer(newVal);
-                    int newVal = getHexVal(spField) & 0xff;
+            } catch (Exception ex) {
-                    machine.getCpu().setStackPointer(newVal);
+                // Swallow exception
-                } catch (Exception ex) {
-                    // Swallow exception
-                }
-
-                updateState();
             }
+
+            updateState();
         });
 
-        aField.addActionListener(new ActionListener() {
+        aField.addActionListener(e -> {
-            @Override
+            try {
-            public void actionPerformed(ActionEvent e) {
+                int newVal = getHexVal(aField) & 0xff;
-                try {
+                machine.getCpu().setAccumulator(newVal);
-                    int newVal = getHexVal(aField) & 0xff;
+            } catch (Exception ex) {
-                    machine.getCpu().setAccumulator(newVal);
+                // Swallow exception
-                } catch (Exception ex) {
-                    // Swallow exception
-                }
-
-                updateState();
             }
+
+            updateState();
         });
 
-        xField.addActionListener(new ActionListener() {
+        xField.addActionListener(e -> {
-            @Override
+            try {
-            public void actionPerformed(ActionEvent e) {
+                int newVal = getHexVal(xField) & 0xff;
-                try {
+                machine.getCpu().setXRegister(newVal);
-                    int newVal = getHexVal(xField) & 0xff;
+            } catch (Exception ex) {
-                    machine.getCpu().setXRegister(newVal);
+                // Swallow exception
-                } catch (Exception ex) {
-                    // Swallow exception
-                }
-
-                updateState();
             }
+
+            updateState();
         });
 
-        yField.addActionListener(new ActionListener() {
+        yField.addActionListener(e -> {
-            @Override
+            try {
-            public void actionPerformed(ActionEvent e) {
+                int newVal = getHexVal(yField) & 0xff;
-                try {
+                machine.getCpu().setYRegister(newVal);
-                    int newVal = getHexVal(yField) & 0xff;
+            } catch (Exception ex) {
-                    machine.getCpu().setYRegister(newVal);
+                // Swallow exception
-                } catch (Exception ex) {
-                    // Swallow exception
-                }
-
-                updateState();
             }
+
+            updateState();
         });
 
         constraints.anchor = GridBagConstraints.LINE_START;

src/main/java/com/loomcom/symon/ui/TraceLog.java

@@ -44,7 +44,7 @@ public class TraceLog extends JFrame {
     private static final int       MAX_LOG_LENGTH = 50000;
 
     public TraceLog() {
-        traceLog = new FifoRingBuffer<Cpu.CpuState>(MAX_LOG_LENGTH);
+        traceLog = new FifoRingBuffer<>(MAX_LOG_LENGTH);
         setMinimumSize(MIN_SIZE);
         setPreferredSize(PREFERRED_SIZE);
         setResizable(true);

src/main/java/com/loomcom/symon/ui/VideoWindow.java

@@ -122,12 +122,10 @@ public class VideoWindow extends JFrame implements DeviceChangeListener {
      */
     private class CursorBlinker implements Runnable {
         public void run() {
-            SwingUtilities.invokeLater(new Runnable() {
+            SwingUtilities.invokeLater(() -> {
-                public void run() {
+                if (cursorBlinkRate > 0) {
-                    if (cursorBlinkRate > 0) {
+                    hideCursor = !hideCursor;
-                        hideCursor = !hideCursor;
+                    repaint();
-                        repaint();
-                    }
                 }
             });
         }

src/main/java/com/loomcom/symon/util/FifoRingBuffer.java

@@ -38,7 +38,7 @@ public class FifoRingBuffer<E> implements Iterable<E> {
     private int maxLength;
 
     public FifoRingBuffer(int maxLength) {
-        this.fifoBuffer = new LinkedList<E>();
+        this.fifoBuffer = new LinkedList<>();
         this.maxLength = maxLength;
     }
 

src/main/java/com/loomcom/symon/util/HexUtil.java

@@ -121,9 +121,6 @@ public class HexUtil {
      * @return Four digit, zero padded hexadecimal string.
      */
     public static String wordToHex(int val) {
-        StringBuilder sb = new StringBuilder(4);
+        return HEX_CONSTANTS[(val >> 8) & 0xff] + HEX_CONSTANTS[val & 0xff];
-        sb.append(HEX_CONSTANTS[(val >> 8) & 0xff]);
-        sb.append(HEX_CONSTANTS[val & 0xff]);
-        return sb.toString();
     }
 }