Bugfixes, change logger, update copyright

- IR field in status panel now correctly displays the next instruction
  to be executed, instead of the instruction that was just executed.

- Switched from built-in Java util logger to Logback

- Updated all copyright strings to 2016

pom.xml

@@ -35,6 +35,11 @@
         </repository>
     </repositories>
     <dependencies>
+        <dependency>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-classic</artifactId>
+            <version>1.1.3</version>
+        </dependency>
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the
@@ -25,8 +25,9 @@ package com.loomcom.symon;
 
 import com.loomcom.symon.exceptions.MemoryAccessException;
 import com.loomcom.symon.util.HexUtil;
-import java.util.logging.Level;
+import org.slf4j.Logger;
-import java.util.logging.Logger;
+import org.slf4j.LoggerFactory;
+
 
 /**
  * This class provides a simulation of the MOS 6502 CPU's state machine.
@@ -35,6 +36,8 @@ import java.util.logging.Logger;
  */
 public class Cpu implements InstructionTable {
 
+    private final static Logger logger = LoggerFactory.getLogger(Cpu.class.getName());
+
     /* Process status register mnemonics */
     public static final int P_CARRY       = 0x01;
     public static final int P_ZERO        = 0x02;
@@ -146,6 +149,8 @@ public class Cpu implements InstructionTable {
         state.a = 0;
         state.x = 0;
         state.y = 0;
+
+        peekAhead();
     }
 
     public void step(int num) throws MemoryAccessException {
@@ -732,6 +737,18 @@ public class Cpu implements InstructionTable {
         }
 
         delayLoop(state.ir);
+
+        // Peek ahead to the next insturction and arguments
+        peekAhead();
+    }
+
+    private void peekAhead() throws MemoryAccessException {
+        state.nextIr = bus.read(state.pc);
+        int nextInstSize = Cpu.instructionSizes[state.nextIr];
+        for (int i = 1; i < nextInstSize; i++) {
+            int nextRead = (state.pc + i) % bus.endAddress();
+            state.nextArgs[i-1] = bus.read(nextRead);
+        }
     }
 
     private void handleIrq(int returnPc) throws MemoryAccessException {
@@ -1117,6 +1134,14 @@ public class Cpu implements InstructionTable {
 
     public void setProgramCounter(int addr) {
         state.pc = addr;
+
+        // As a side-effect of setting the program counter,
+        // we want to peek ahead at the next state.
+        try {
+            peekAhead();
+        } catch (MemoryAccessException ex) {
+            logger.error("Could not peek ahead at next instruction state.");
+        }
     }
 
     public int getStackPointer() {
@@ -1359,15 +1384,20 @@ public class Cpu implements InstructionTable {
          */
         public int pc;
         /**
-         * Instruction Register
+         * Last Loaded Instruction Register
          */
         public int ir;
-        public int lastPc;
+        /**
+         * Peek-Ahead to next IR
+         */
+        public int nextIr;
         public int[] args = new int[2];
+        public int[] nextArgs = new int[2];
         public int instSize;
         public boolean opTrap;
         public boolean irqAsserted;
         public boolean nmiAsserted;
+        public int lastPc;
 
         /* Status Flag Register bits */
         public boolean carryFlag;
@@ -1387,7 +1417,7 @@ public class Cpu implements InstructionTable {
         /**
          * Snapshot a copy of the CpuState.
          *
-         * (This is a copy constructor rather than an implementation of <code>Clonable</code>
+         * (This is a copy constructor rather than an implementation of <code>Cloneable</code>
          * based on Josh Bloch's recommendation)
          *
          * @param s The CpuState to copy.
@@ -1399,9 +1429,12 @@ public class Cpu implements InstructionTable {
             this.sp = s.sp;
             this.pc = s.pc;
             this.ir = s.ir;
+            this.nextIr = s.nextIr;
             this.lastPc = s.lastPc;
             this.args[0] = s.args[0];
             this.args[1] = s.args[1];
+            this.nextArgs[0] = s.nextArgs[0];
+            this.nextArgs[1] = s.nextArgs[1];
             this.instSize = s.instSize;
             this.opTrap = s.opTrap;
             this.irqAsserted = s.irqAsserted;
@@ -1421,7 +1454,7 @@ public class Cpu implements InstructionTable {
          * @return a string formatted for the trace log.
          */
         public String toTraceEvent() {
-            String opcode = disassembleOp();
+            String opcode = disassembleLastOp();
             StringBuilder sb = new StringBuilder(getInstructionByteStatus());
             sb.append("  ");
             sb.append(String.format("%-14s", opcode));
@@ -1483,13 +1516,13 @@ public class Cpu implements InstructionTable {
             }
         }
 
-
         /**
-         * Given an opcode and its operands, return a formatted name.
+         * Return a formatted string representing the last instruction and
+         * operands that were executed.
          *
          * @return A string representing the mnemonic and operands of the instruction
          */
-        public String disassembleOp() {
+        private String disassembleOp(int ir, int[] args) {
             String mnemonic = opcodeNames[ir];
 
             if (mnemonic == null) {
@@ -1535,6 +1568,20 @@ public class Cpu implements InstructionTable {
             return sb.toString();
         }
 
+        public String disassembleLastOp() {
+            return disassembleOp(ir, args);
+        }
+
+        /**
+         * Return a formatted string representing the next instruction and
+         * operands to be executed.
+         *
+         * @return A string representing the mnemonic and operands of the instruction
+         */
+        public String disassembleNextOp() {
+            return disassembleOp(nextIr, nextArgs);
+        }
+
         /**
          * Given two bytes, return an address.
          */

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *                    Maik Merten <maikmerten@googlemail.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyrighi (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the
@@ -31,14 +31,14 @@ import com.loomcom.symon.exceptions.SymonException;
 import com.loomcom.symon.machines.Machine;
 import com.loomcom.symon.ui.*;
 import com.loomcom.symon.ui.Console;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import javax.swing.*;
 import javax.swing.border.EmptyBorder;
 import java.awt.*;
 import java.awt.event.*;
 import java.io.*;
-import java.util.logging.Level;
-import java.util.logging.Logger;
 
 /**
  * Symon Simulator Interface and Control.
@@ -50,6 +50,8 @@ import java.util.logging.Logger;
  */
 public class Simulator {
 
+    private final static Logger logger = LoggerFactory.getLogger(Simulator.class.getName());
+
     // UI constants
     private static final int  DEFAULT_FONT_SIZE    = 12;
     private static final Font DEFAULT_FONT         = new Font(Font.MONOSPACED, Font.PLAIN, DEFAULT_FONT_SIZE);
@@ -66,8 +68,6 @@ public class Simulator {
     //
     private static final int MAX_STEPS_BETWEEN_UPDATES = 20000;
 
-    private final static Logger logger = Logger.getLogger(Simulator.class.getName());
-
     // The simulated machine
     private Machine machine;
 
@@ -287,7 +287,7 @@ public class Simulator {
         }
 
         try {
-            logger.log(Level.INFO, "Reset requested. Resetting CPU.");
+            logger.info("Reset requested. Resetting CPU.");
             // Reset CPU
             machine.getCpu().reset();
             // Clear the console.
@@ -302,15 +302,9 @@ public class Simulator {
                 }
             }
             // Update status.
-            SwingUtilities.invokeLater(new Runnable() {
+            updateVisibleState();
-                public void run() {
-                    // Now update the state
-                    statusPane.updateState();
-                    memoryWindow.updateState();
-                }
-            });
         } catch (MemoryAccessException ex) {
-            logger.log(Level.SEVERE, "Exception during simulator reset: " + ex.getMessage());
+            logger.error("Exception during simulator reset", ex);
         }
     }
 
@@ -322,17 +316,9 @@ public class Simulator {
             for (int i = 0; i < numSteps; i++) {
                 step();
             }
-            SwingUtilities.invokeLater(new Runnable() {
+            updateVisibleState();
-                public void run() {
-                    if (traceLog.isVisible()) {
-                        traceLog.refresh();
-                    }
-                    statusPane.updateState();
-                    memoryWindow.updateState();
-                }
-            });
         } catch (SymonException ex) {
-            logger.log(Level.SEVERE, "Exception during simulator step: " + ex.getMessage());
+            logger.error("Exception during simulator step", ex);
             ex.printStackTrace();
         }
     }
@@ -359,7 +345,7 @@ public class Simulator {
                 machine.getAcia().rxWrite((int) console.readInputChar());
             }
         } catch (FifoUnderrunException ex) {
-            logger.severe("Console type-ahead buffer underrun!");
+            logger.error("Console type-ahead buffer underrun!");
         }
 
         if (videoWindow != null && stepsSinceLastCrtcRefresh++ > stepsBetweenCrtcRefreshes) {
@@ -373,13 +359,7 @@ public class Simulator {
         // a delay, so we don't want to overwhelm the Swing event processing thread
         // with requests. Limit the number of ui updates that can be performed.
         if (stepsSinceLastUpdate++ > MAX_STEPS_BETWEEN_UPDATES) {
-            SwingUtilities.invokeLater(new Runnable() {
+            updateVisibleState();
-                public void run() {
-                    // Now update the state
-                    statusPane.updateState();
-                    memoryWindow.updateState();
-                }
-            });
             stepsSinceLastUpdate = 0;
         }
 
@@ -394,8 +374,7 @@ public class Simulator {
             machine.getBus().write(addr++, program[i] & 0xff);
         }
 
-        logger.log(Level.INFO, "Loaded " + i + " bytes at address 0x" +
+        logger.info("Loaded {} bytes at address 0x{}", i, Integer.toString(startAddress, 16));
-                               Integer.toString(startAddress, 16));
 
         // After loading, be sure to reset and
         // Reset (but don't clear memory, naturally)
@@ -405,16 +384,9 @@ public class Simulator {
         machine.getCpu().setProgramCounter(preferences.getProgramStartAddress());
 
         // Immediately update the UI.
-        SwingUtilities.invokeLater(new Runnable() {
+        updateVisibleState();
-            public void run() {
-                // Now update the state
-                statusPane.updateState();
-                memoryWindow.updateState();
-            }
-        });
     }
 
-
     /**
      * The main run thread.
      */
@@ -430,7 +402,7 @@ public class Simulator {
         }
 
         public void run() {
-            logger.log(Level.INFO, "Starting main run loop.");
+            logger.info("Starting main run loop.");
             isRunning = true;
 
             SwingUtilities.invokeLater(new Runnable() {
@@ -449,8 +421,7 @@ public class Simulator {
                     step();
                 } while (shouldContinue());
             } catch (SymonException ex) {
-                logger.log(Level.SEVERE, "Exception in main simulator run thread. Exiting run.");
+                logger.error("Exception in main simulator run thread. Exiting run.", ex);
-                ex.printStackTrace();
             }
 
             SwingUtilities.invokeLater(new Runnable() {
@@ -529,10 +500,10 @@ public class Simulator {
                     }
                 }
             } catch (IOException ex) {
-                logger.log(Level.SEVERE, "Unable to read program file: " + ex.getMessage());
+                logger.error("Unable to read program file.", ex);
                 JOptionPane.showMessageDialog(mainWindow, ex.getMessage(), "Failure", JOptionPane.ERROR_MESSAGE);
             } catch (MemoryAccessException ex) {
-                logger.log(Level.SEVERE, "Memory access error loading program: " + ex.getMessage());
+                logger.error("Memory access error loading program", ex);
                 JOptionPane.showMessageDialog(mainWindow, ex.getMessage(), "Failure", JOptionPane.ERROR_MESSAGE);
             }
         }
@@ -555,34 +526,36 @@ public class Simulator {
 
                         if (fileSize != machine.getRomSize()) {
                             throw new IOException("ROM file must be exactly " + String.valueOf(machine.getRomSize()) + " bytes.");
-                        } else {
-                            
-                            // Load the new ROM image
-                            Memory rom = Memory.makeROM(machine.getRomBase(), machine.getRomBase() + machine.getRomSize() - 1, romFile);
-                            machine.setRom(rom);
-
-                            // Now, reset
-                            machine.getCpu().reset();
-
-                            logger.log(Level.INFO, "ROM File `" + romFile.getName() + "' loaded at " +
-                                                   String.format("0x%04X", machine.getRomBase()));
-                            // TODO: "Don't Show Again" checkbox
-                            JOptionPane.showMessageDialog(mainWindow,
-                                    "Loaded Successfully At " +
-                                            String.format("$%04X", machine.getRomBase()),
-                                    "OK",
-                                    JOptionPane.PLAIN_MESSAGE);
                         }
+                            
+                        // Load the new ROM image
+                        Memory rom = Memory.makeROM(machine.getRomBase(), machine.getRomBase() + machine.getRomSize() - 1, romFile);
+                        machine.setRom(rom);
+
+                        // Now, reset
+                        machine.getCpu().reset();
+
+                        updateVisibleState();
+
+                        logger.info("ROM File `{}' loaded at {}", romFile.getName(),
+                                String.format("0x%04X", machine.getRomBase()));
+                        // TODO: "Don't Show Again" checkbox
+                        JOptionPane.showMessageDialog(mainWindow,
+                                "Loaded Successfully At " +
+                                        String.format("$%04X", machine.getRomBase()),
+                                "OK",
+                                JOptionPane.PLAIN_MESSAGE);
+
                     }
                 }
             } catch (IOException ex) {
-                logger.log(Level.SEVERE, "Unable to read ROM file: " + ex.getMessage());
+                logger.error("Unable to read ROM file: {}", ex.getMessage());
                 JOptionPane.showMessageDialog(mainWindow, ex.getMessage(), "Failure", JOptionPane.ERROR_MESSAGE);
             } catch (MemoryRangeException ex) {
-                logger.log(Level.SEVERE, "Memory range error while loading ROM file: " + ex.getMessage());
+                logger.error("Memory range error while loading ROM file: {}", ex.getMessage());
                 JOptionPane.showMessageDialog(mainWindow, ex.getMessage(), "Failure", JOptionPane.ERROR_MESSAGE);
             } catch (MemoryAccessException ex) {
-                logger.log(Level.SEVERE, "Memory access error while loading ROM file: " + ex.getMessage());
+                logger.error("Memory access error while loading ROM file: {}", ex.getMessage());
                 JOptionPane.showMessageDialog(mainWindow, ex.getMessage(), "Failure", JOptionPane.ERROR_MESSAGE);
             }
         }
@@ -837,4 +810,18 @@ public class Simulator {
         }
     }
 
+    private void updateVisibleState() {
+        // Immediately update the UI.
+        SwingUtilities.invokeLater(new Runnable() {
+            public void run() {
+                // Now update the state
+                statusPane.updateState();
+                memoryWindow.updateState();
+                if (traceLog.shouldUpdate()) {
+                    traceLog.refresh();
+                }
+            }
+        });
+    }
+
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *                    Maik Merten <maikmerten@googlemail.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *                    Maik Merten <maikmerten@googlemail.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *                    Maik Merten <maikmerten@googlemail.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *                    Maik Merten <maikmerten@googlemail.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *                    Maik Merten <maikmerten@googlemail.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *                    Maik Merten <maikmerten@googlemail.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
@@ -28,13 +28,14 @@ import com.loomcom.symon.Bus;
 import com.loomcom.symon.Cpu;
 import com.loomcom.symon.devices.*;
 import com.loomcom.symon.exceptions.MemoryRangeException;
-import java.io.File;
+import org.slf4j.Logger;
-import java.util.logging.Logger;
+import org.slf4j.LoggerFactory;
 
+import java.io.File;
 
 public class SymonMachine implements Machine {
     
-    private final static Logger logger = Logger.getLogger(SymonMachine.class.getName());
+    private final static Logger logger = LoggerFactory.getLogger(SymonMachine.class.getName());
     
     // Constants used by the simulated system. These define the memory map.
     private static final int BUS_BOTTOM = 0x0000;
@@ -86,11 +87,10 @@ public class SymonMachine implements Machine {
         // TODO: Make this configurable, of course.
         File romImage = new File("rom.bin");
         if (romImage.canRead()) {
-            logger.info("Loading ROM image from file " + romImage);
+            logger.info("Loading ROM image from file {}", romImage);
             this.rom = Memory.makeROM(ROM_BASE, ROM_BASE + ROM_SIZE - 1, romImage);
         } else {
-            logger.info("Default ROM file " + romImage +
+            logger.info("Default ROM file {} not found, loading empty R/W memory image.", romImage);
-                        " not found, loading empty R/W memory image.");
             this.rom = Memory.makeRAM(ROM_BASE, ROM_BASE + ROM_SIZE - 1);
         }
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the
@@ -32,9 +32,6 @@ import javax.swing.border.EtchedBorder;
 import java.awt.*;
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-import java.util.regex.Pattern;
 
 /**
  * UI component that displays the current state of the simulated CPU.
@@ -154,7 +151,7 @@ public class StatusPanel extends JPanel {
 
         // Create and add register and address labels
         statusFlagsLabel = makeLabel("Flags");
-        opcodeLabel = makeLabel("IR");
+        opcodeLabel = makeLabel("Next IR");
         pcLabel = makeLabel("PC");
         spLabel = makeLabel("SP");
         aLabel = makeLabel("A");
@@ -317,7 +314,9 @@ public class StatusPanel extends JPanel {
         negativeFlagLabel.setIcon(iconForFlag(status, 7));
 
         // Update the register and address displays
-        opcodeField.setText(cpu.getCpuState().disassembleOp());
+
+        // We always want to show the NEXT instruction that will be executed
+        opcodeField.setText(cpu.getCpuState().disassembleNextOp());
         pcField.setText(cpu.getProgramCounterStatus());
         spField.setText(cpu.getStackPointerStatus());
         aField.setText(cpu.getAccumulatorStatus());

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *                    Maik Merten <maikmerten@googlemail.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
@@ -113,4 +113,8 @@ public class TraceLog extends JFrame {
         traceLogTextArea.setEnabled(true);
     }
 
+    public boolean shouldUpdate() {
+        return isVisible() && traceLogTextArea.isEnabled();
+    }
+
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the