removed unused code

src/main/java/ntsakonas/retro/chipate/simulator/Chip8System.java

@@ -98,7 +98,6 @@ public interface SystemState
     {
         synchronized (timerLock)
         {
-           // System.out.println("tick "+timerTick);
             if (timerTick > 0)
                 --timerTick;
         }
@@ -277,10 +276,7 @@ public byte waitForKey()
             {
                 // NOTE:: this is a blocking method.
                 // it will return when a key is pressed and then released
-                System.out.println("waiting for key...");
-                byte b = keyboard.waitForKey();
-                System.out.println("key "+b+" pressed...");
-                return b;
+                return keyboard.waitForKey();
             }
 
             @Override
@@ -312,7 +308,7 @@ public void setTone(byte value)
             {
                 // check specs how tone is supposed to work
                 // check the existing emulator how it does it
-                // todo :9mplement tone
+                // todo :Implement tone
             }
 
             @Override

src/main/java/ntsakonas/retro/chipate/simulator/ChipInstructionMicrocodeDecoder.java

@@ -222,7 +222,6 @@ else if (lsb == 0x00 && msb == (byte)0xE0)
             int numOfPatternBytes = (Math.min(N,15));
             byte posX = state.getRegister(X);
             byte posY = state.getRegister(Y);
-            //System.out.println(String.format("write %d (%d) @ (%d,%d)",numOfPatternBytes,N,posX,posY));
             boolean spriteCollisionDetected = false;
             for (int i=0;i<numOfPatternBytes;i++)
             {

src/main/java/ntsakonas/retro/chipate/simulator/RealTimeClock.java

@@ -4,21 +4,21 @@
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
 
-public class RealTimeClock
-{
+/*
+    Emulates the 60Hz tick that increments the tick counter (used in most programs for time keeping)
+ */
+public class RealTimeClock {
     private ScheduledExecutorService rtcExecutor;
-    RealTimeClock()
-    {
+
+    RealTimeClock() {
         rtcExecutor = Executors.newScheduledThreadPool(1);
     }
 
-    void start(Runnable callback)
-    {
-        rtcExecutor.scheduleAtFixedRate(callback,0L,16666L, TimeUnit.MICROSECONDS);
+    void start(Runnable callback) {
+        rtcExecutor.scheduleAtFixedRate(callback, 0L, 16666L, TimeUnit.MICROSECONDS);
     }
 
-    void stop()
-    {
+    void stop() {
         if (!rtcExecutor.isTerminated())
             rtcExecutor.shutdownNow();
     }

src/main/java/ntsakonas/retro/chipate/simulator/Simulator.java

@@ -87,10 +87,12 @@ private void simulateRealSystemTiming()
         // it is no known how many instructions were executed per CHIP8 instruction
         // but lets assume 20.. that means each CHIP8 instruction would last 90.8 microSec
         // lets sleep for this time to emulate the original timing
-        // NOTE: the minimum delays obtainable in Java is 1 msec, which is fine.
+        // UPDATE: using 1ms the emulations is very fast. using an emulated clock of 500Hz as described here
+        // https://jackson-s.me/2019/07/13/Chip-8-Instruction-Scheduling-and-Frequency.html
+        // the emulation speed is better
         try
         {
-            Thread.sleep(1L);
+            Thread.sleep(2L);
         } catch (InterruptedException e)
         {
             e.printStackTrace();

src/main/java/ntsakonas/retro/chipate/ui/ChipUI.java

@@ -7,7 +7,10 @@
 
 import javax.swing.*;
 import java.awt.*;
-import java.awt.event.*;
+import java.awt.event.KeyAdapter;
+import java.awt.event.KeyEvent;
+import java.awt.event.WindowAdapter;
+import java.awt.event.WindowEvent;
 import java.awt.image.BufferedImage;
 import java.io.IOException;
 import java.nio.file.Files;
@@ -17,8 +20,7 @@
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
 
-class SharedVideoRam
-{
+class SharedVideoRam {
     public byte[] videoRam;
 }
 
@@ -27,48 +29,42 @@ public class ChipUI {
 
     SystemDisplay systemDisplay = vram -> sharedVideoRam.videoRam = Arrays.copyOf(vram, vram.length);
 
-    private final int SIMULATOR_WINDOW_WIDTH = 400;
-    private final int SIMULATOR_WINDOW_HEIGHT = 380;
+    private final int SIMULATOR_WINDOW_WIDTH = 320;
+    private final int SIMULATOR_WINDOW_HEIGHT = 320;
 
     private JFrame topLevelFrame;
     private static Simulator simulator;
 
 
-    public ChipUI()
-    {
+    public ChipUI() {
     }
 
-    public SystemDisplay getSystemDisplay()
-    {
+    public SystemDisplay getSystemDisplay() {
         return systemDisplay;
     }
+
     /**
      * Create the GUI and show it.  For thread safety,
      * this method should be invoked from the
      * event-dispatching thread.
      */
     private void createAndShowGUI() {
         //Create and set up the window.
-        //JFrame.setDefaultLookAndFeelDecorated(true);
         topLevelFrame = new JFrame("Chip-8 Emulator");
         topLevelFrame.setResizable(false);
         topLevelFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         topLevelFrame.setBackground(new Color(128, 128, 128));
         topLevelFrame.setPreferredSize(new Dimension(SIMULATOR_WINDOW_WIDTH, SIMULATOR_WINDOW_HEIGHT));
         Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
-        topLevelFrame.setLocation(screenSize.width / 2 - SIMULATOR_WINDOW_WIDTH / 2, screenSize.height / 2 - SIMULATOR_WINDOW_HEIGHT /2 );
+        topLevelFrame.setLocation(screenSize.width / 2 - SIMULATOR_WINDOW_WIDTH / 2, screenSize.height / 2 - SIMULATOR_WINDOW_HEIGHT / 2);
 
-        //topLevelFrame.getContentPane().add(new SimulatorDisplay(sharedVideoRam), BorderLayout.CENTER);
         topLevelFrame.add(new SimulatorDisplay(sharedVideoRam), BorderLayout.CENTER);
         topLevelFrame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
-        topLevelFrame.addWindowListener(new WindowAdapter()
-        {
+        topLevelFrame.addWindowListener(new WindowAdapter() {
             @Override
-            public void windowClosing(WindowEvent e)
-            {
+            public void windowClosing(WindowEvent e) {
                 simulator.terminate();
                 topLevelFrame.dispose();
-                System.out.println("exit");
                 System.exit(0);
 
             }
@@ -78,45 +74,35 @@ public void windowClosing(WindowEvent e)
     }
 
 
-
-    public  void startSimulatorUI(String romPath) throws IOException
-    {
+    public void startSimulatorUI(String romPath) throws IOException {
         final byte[] romBytes = Files.readAllBytes(Paths.get(romPath));
         javax.swing.SwingUtilities.invokeLater(() -> {
             createAndShowGUI();
             Keyboard keyboard = new Keyboard();
             connectKeyboard(keyboard);
-            simulator = new Simulator(keyboard,getSystemDisplay());
+            simulator = new Simulator(keyboard, getSystemDisplay());
             // TESTING THE DEBUGGER
             //simulator.attachDebugger(new CommandLineDebugger());
             simulator.run(romBytes);
         });
     }
 
-    private void connectKeyboard(KeyboardInput keyboardInput)
-    {
-        topLevelFrame.addKeyListener(new KeyAdapter()
-        {
+    private void connectKeyboard(KeyboardInput keyboardInput) {
+        topLevelFrame.addKeyListener(new KeyAdapter() {
             @Override
-            public void keyPressed(KeyEvent keyEvent)
-            {
-                //System.out.println("key pressed:"+keyEvent.getKeyChar());
+            public void keyPressed(KeyEvent keyEvent) {
                 keyboardInput.keyPressed(keyEvent.getKeyChar());
             }
 
             @Override
-            public void keyReleased(KeyEvent keyEvent)
-            {
-                //System.out.println("key released:"+keyEvent.getKeyChar());
+            public void keyReleased(KeyEvent keyEvent) {
                 keyboardInput.keyReleased(keyEvent.getKeyChar());
             }
         });
     }
 
-    public static void main(String[] args) throws IOException
-    {
-        if (args.length == 0)
-        {
+    public static void main(String[] args) throws IOException {
+        if (args.length == 0) {
             System.out.println("--- Chip-8 simulator by Nick Tsakonas (c) 2018");
             System.out.println("--- usage simulator input.rom [base]");
             System.out.println("          input.rom  - the rom to execute (located at 0x0200)");
@@ -128,8 +114,7 @@ public static void main(String[] args) throws IOException
 
 }
 
-class SimulatorDisplay extends  JPanel
-{
+class SimulatorDisplay extends JPanel {
     private final int SCREEN_WIDTH_PX = 64;
     private final int SCREEN_HEIGHT_PX = 32;
     final int SCALE = 5;
@@ -140,61 +125,45 @@ class SimulatorDisplay extends  JPanel
     private final SharedVideoRam sharedVideoRam;
     private BufferedImage vramImage;
 
-    public SimulatorDisplay(SharedVideoRam sharedVideoRam)
-    {
+    public SimulatorDisplay(SharedVideoRam sharedVideoRam) {
         this.sharedVideoRam = sharedVideoRam;
         setupDisplay();
     }
 
-    private void setupDisplay()
-    {
+    private void setupDisplay() {
         setPreferredSize(new Dimension(SCREEN_WIDTH_PX, SCREEN_HEIGHT_PX));
         setBackground(new Color(0, 0, 0));
         vramImage = new BufferedImage(displaySizeX, displaySizeY + displayYOffset, BufferedImage.TYPE_INT_RGB);
         startScreenUpdate();
     }
 
     @Override
-    protected void paintComponent(Graphics g)
-    {
-        //super.paintComponent(g);
+    protected void paintComponent(Graphics g) {
         g.drawImage(vramImage, 0, 0, this);
         Toolkit.getDefaultToolkit().sync();
     }
 
-    private void startScreenUpdate()
-    {
-        ScheduledExecutorService rtcExecutor =Executors.newScheduledThreadPool(1);
-        rtcExecutor.scheduleAtFixedRate(new Runnable()
-        {
+    private void startScreenUpdate() {
+        ScheduledExecutorService rtcExecutor = Executors.newScheduledThreadPool(1);
+        rtcExecutor.scheduleAtFixedRate(new Runnable() {
             @Override
-            public void run()
-            {
-                //synchronized (sharedVideoRam)
-                {
-                    if (sharedVideoRam.videoRam != null && sharedVideoRam.videoRam.length>0)
-                        refresh(sharedVideoRam.videoRam);
-                }
+            public void run() {
+                if (sharedVideoRam.videoRam != null && sharedVideoRam.videoRam.length > 0)
+                    refresh(sharedVideoRam.videoRam);
             }
 
-            public void refresh(byte[] vram)
-            {
-                for (int y = 0; y < SCREEN_HEIGHT_PX; y++)
-                {
-                    for (int x = 0; x < SCREEN_WIDTH_PX / 8; x++)
-                    {
+            public void refresh(byte[] vram) {
+                for (int y = 0; y < SCREEN_HEIGHT_PX; y++) {
+                    for (int x = 0; x < SCREEN_WIDTH_PX / 8; x++) {
                         int videoByte = getVideoByte(vram, y, x);
                         int mask = 0x80;
-                        for (int bits = 0; bits < 8; bits++)
-                        {
+                        for (int bits = 0; bits < 8; bits++) {
                             boolean isBitOn = ((videoByte & mask) == mask);
                             int ypos = y * SCALE + displayYOffset;
                             int xpos = (x * 8 + bits) * SCALE;
-                            if (SCALE == 1)
-                            {
+                            if (SCALE == 1) {
                                 vramImage.setRGB(xpos, ypos, isBitOn ? 0xffffff : 0x000000);
-                            } else
-                            {
+                            } else {
                                 for (int yRepeat = 0; yRepeat < SCALE; ++yRepeat)
                                     for (int xRepeat = 0; xRepeat < SCALE; ++xRepeat)
                                         vramImage.setRGB(xpos + xRepeat, ypos + yRepeat, isBitOn ? 0xffffff : 0x000000);
@@ -205,23 +174,13 @@ public void refresh(byte[] vram)
                 }
                 repaint();
             }
-            private int getVideoByte(byte[] vram, int y, int x)
-            {
+
+            private int getVideoByte(byte[] vram, int y, int x) {
                 return Byte.toUnsignedInt(vram[y * 8 + x]);
             }
 
-
         }, 0L, 5L, TimeUnit.MILLISECONDS);
 
     }
 
-}
-
-/*
-//    http://www.baeldung.com/java-images
-//    https://stackoverflow.com/questions/5281262/how-to-close-the-window-in-awt
-//    https://www.mkyong.com/java/how-to-convert-byte-to-bufferedimage-in-java/
-//    https://beginnersbook.com/2015/06/java-awt-tutorial/
-//
-//    https://www.darkcoding.net/software/non-blocking-console-io-is-not-possible/
-*/
+}