Version 1.0.10 - changes by Nick

- fixed disk stepping bug for Mabel's Mansion using my code from AppleWin
- patch loaded ROM's empty slots with faux-floating bus data so Mabel's Mansion works
- revert CPU status bug introduced in 1.0.9 - V and R used the same bit
- fixed BRK bug by adding extra PC increment

README.md

@@ -1,6 +1,10 @@
 # AppleIIGo
 Apple //e emulator Java applet
 
-Original version: Copyright 2006 Marc S. Ressl
+Original version: Copyright 2006 Marc S. Ressl, with parts adapted from code by
+- Steven E. Hugg
+- Doug Kwan
+- Randy Frank
+- Ben Koning
 
 Subsequent versions: Copyright 2008-2015 Nick Westgate

Source/AppleDisplay.java

@@ -2,7 +2,7 @@
 /**
  * AppleIIGo
  * Display processing
- * (C) 2006 by Marc S. Ressl (ressl@lonetree.com)
+ * Copyright 2006 by Marc S. Ressl (mressl@gmail.com)
  * Released under the GPL
  */
 
@@ -224,6 +224,18 @@ public class AppleDisplay implements Runnable {
 		return displayScale;
     }
 	
+	public int getSizeX()
+	{
+		precalcDisplay();
+		return displayScaledSizeX;
+	}
+	
+	public int getSizeY()
+	{
+		precalcDisplay();
+		return displayScaledSizeY;
+	}
+	
 	/**
 	 * Set refresh rate
 	 *
@@ -459,8 +471,8 @@ public class AppleDisplay implements Runnable {
 		boolean isDoubleTextMode = ((graphicsMode & EmAppleII.GR_80CHAR) == EmAppleII.GR_80CHAR);
 		boolean isDoubleGraphicsMode = ((graphicsMode & (EmAppleII.GR_80CHAR | EmAppleII.GR_DHIRES)) == (EmAppleII.GR_80CHAR | EmAppleII.GR_DHIRES));
 
-		int baseAddressText = isPage2 ? apple.MEM_MAIN_RAM2 : apple.MEM_MAIN_TEXT;
-		int baseAddressHires = isPage2 ? apple.MEM_MAIN_RAM3 : apple.MEM_MAIN_HIRES;
+		int baseAddressText = isPage2 ? EmAppleII.MEM_MAIN_RAM2 : EmAppleII.MEM_MAIN_TEXT;
+		int baseAddressHires = isPage2 ? EmAppleII.MEM_MAIN_RAM3 : EmAppleII.MEM_MAIN_HIRES;
 
 		// Set char map
 		if (isCharsetUpdateRequested) {
@@ -769,7 +781,7 @@ public class AppleDisplay implements Runnable {
 	}
 	private void renderText(int baseAddress, boolean isMixedMode) {
 		int screenCharY, screenCharYStart = isMixedMode ? 20 : 0;
-		int displayOffset, sourceOffset;
+		int displayOffset;
 		int address, addressEnd, addressStart;
 		
 		displayOffset = screenCharYStart * DISPLAY_CHAR_SIZE_Y * DISPLAY_SIZE_X;
@@ -820,7 +832,7 @@ public class AppleDisplay implements Runnable {
 	}
 	private void renderDoubleText(int baseAddress, boolean isMixedMode) {
 		int screenCharY, screenCharYStart = isMixedMode ? 20 : 0;
-		int displayOffset, sourceOffset;
+		int displayOffset;
 		int address, addressEnd, addressStart;
 		
 		displayOffset = screenCharYStart * DISPLAY_CHAR_SIZE_Y * DISPLAY_SIZE_X;
@@ -873,7 +885,7 @@ public class AppleDisplay implements Runnable {
 	}
 	private void renderLores(int baseAddress, boolean isMixedMode) {
 		int screenCharY, screenCharYEnd = isMixedMode ? 20 : 24;
-		int displayOffset, sourceOffset;
+		int displayOffset;
 		int address, addressEnd, addressStart;
 		
 		displayOffset = 0;
@@ -904,7 +916,7 @@ public class AppleDisplay implements Runnable {
 	 */
 	private void renderDoubleLores(int baseAddress, boolean isMixedMode) {
 		int screenCharY, screenCharYEnd = isMixedMode ? 20 : 24;
-		int displayOffset, sourceOffset;
+		int displayOffset;
 		int address, addressEnd, addressStart;
 		
 		displayOffset = 0;
@@ -998,7 +1010,7 @@ public class AppleDisplay implements Runnable {
 	}
 	private void renderHires(int baseAddress, boolean isMixedMode) {
 		int screenCharY, screenCharYEnd = isMixedMode ? 20 : 24;
-		int displayOffset, sourceOffset;
+		int displayOffset;
 		int address, addressEnd, addressStart;
 		
 		displayOffset = 0;
@@ -1089,7 +1101,7 @@ public class AppleDisplay implements Runnable {
 	}	
 	private void renderDoubleHires(int baseAddress, boolean isMixedMode) {
 		int screenCharY, screenCharYEnd = isMixedMode ? 20 : 24;
-		int displayOffset, sourceOffset;
+		int displayOffset;
 		int address, addressEnd, addressStart;
 		
 		displayOffset = 0;

Source/AppleIIGo.java

@@ -2,12 +2,53 @@
 /**
  * AppleIIGo
  * The Java Apple II Emulator 
- * (C) 2006 by Marc S. Ressl (ressl@lonetree.com)
- * (C) 2009 by Nick Westgate (Nick.Westgate@gmail.com)
- * Released under the GPL
+ * Copyright 2015 by Nick Westgate (Nick.Westgate@gmail.com)
+ * Copyright 2006 by Marc S. Ressl (mressl@gmail.com)
+ * Released under the GNU General Public License version 2 
+ * See http://www.gnu.org/licenses/
  * 
  * Change list:
  * 
+ * Version 1.0.10 - changes by Nick:
+ * - fixed disk stepping bug for Mabel's Mansion using my code from AppleWin
+ * - patch loaded ROM's empty slots with faux-floating bus data so Mabel's Mansion works
+ * - revert CPU status bug introduced in 1.0.9 - V and R used the same bit
+ * - fixed BRK bug by adding extra PC increment
+ * - NOTE: decimal mode arithmetic fails some tests and should be fixed someday
+ * 
+ * Version 1.0.9 - changes by Nick:
+ * - fixed disk speed-up bug (Sherwood Forest reads with the drive motor off)
+ * - added check for 2IMG header ID
+ * - fixed processor status bugs in BRK, PLP, RTI, NMI, IRQ 
+ * 
+ * Version 1.0.8 - changes by Nick:
+ * - implemented disk writing (only in memory, not persisted)
+ * - added support for .2MG (2IMG) disk images, including lock flag and volume number
+ * - support meta tag for write protect in disk filename eg: NotWritable_Meta_DW0.dsk
+ * 
+ * Version 1.0.7 - changes by Nick:
+ * - fixed disk emulation bug (sense write protect entered write mode)
+ * - now honour diskWritable parameter (but writing is not implemented)
+ * - support meta tag for volume number in disk filename eg: Vol2_Meta_DV2.dsk
+ * - added isPaddleEnabled parameter
+ * - exposed setPaddleEnabled(boolean value), setPaddleInverted(boolean value)
+ * - paddle values are now 255 at startup (ie. correct if disabled/not present)
+ * - minor AppleSpeaker fix (SourceDataLine.class) thanks to William Halliburton
+ * 
+ * Version 1.0.6 - changes by Nick:
+ * - exposed F3/F4 disk swapping method: cycleDisk(int driveNumber)
+ * - exposed reset() method 
+ * - exposed setSpeed(int value) method
+ * 
+ * Version 1.0.5 - changes by Nick:
+ * - added support for .NIB (nibble) disk images  (also inside ZIP archives)
+ * - added disk speedup hacks for DOS (expect ~2x faster reads)
+ * 
+ * Version 1.0.4 - changes by Nick:
+ * - added support for .PO (ProDOS order) disk images (also inside ZIP archives)
+ * - added Command key for Closed-Apple on Mac OS X
+ * - added Home and End keys for Open-Apple and Closed-Apple on full keyboards
+ *
  * Version 1.0.3 - changes by Nick:
  * - fixed paddle values for scaled display window
  * - added "digital" joystick support via numeric keypad arrows
@@ -17,7 +58,7 @@
  * Version 1.0.2 - changes by Nick:
  * - improved sound sync by moving AppleSpeaker into the main thread
  * - added version (F1)
- * - added multiple disks & switching (F3, F4)
+ * - added multiple disks & swapping (F3, F4)
  * - added ZIP archive support
  * - fixed HTTP disk image access bug
  */
@@ -39,6 +80,7 @@ import java.io.OutputStream;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.zip.GZIPInputStream;
+import java.util.zip.ZipEntry;
 import java.util.zip.ZipInputStream;
 
 /**
@@ -48,8 +90,11 @@ import java.util.zip.ZipInputStream;
 public class AppleIIGo extends Applet implements KeyListener, ComponentListener, 
 	MouseListener, MouseMotionListener {
 
-	final String version = "1.0.3";
+	private static final long serialVersionUID = -3302282815441501352L;
+	
+	final String version = "1.0.10";
 	final String versionString = "AppleIIGo Version " + version;
+	final String metaStart = "_meta_";
 
 	// Class instances
 	private EmAppleII apple;
@@ -64,15 +109,14 @@ public class AppleIIGo extends Applet implements KeyListener, ComponentListener,
 	private boolean keyboardUppercaseOnly;
 
 	// Paddle variables
+	private boolean isPaddleEnabled;
 	private boolean isPaddleInverted;
 	
-	// Disk variables
+	// Disk variables - TODO: refactor into a class
 	private String diskDriveResource[] = new String[2];
 	private boolean diskWritable;
-	private String[] disks0;
-	private String[] disks1;
-	private int disk0;
-	private int disk1;
+	private String[][] diskImageNames = {{}, {}};
+	private int diskImageNumber[] = {0, 0};
 
 	/**
  	 * Debug
@@ -116,6 +160,10 @@ public class AppleIIGo extends Applet implements KeyListener, ComponentListener,
 		// Keyboard
 		keyboardUppercaseOnly = getAppletParameter("keyboardUppercaseOnly", "true").equals("true");
 
+		// Paddles
+		isPaddleEnabled = getAppletParameter("paddleEnabled", "true").equals("true");
+		isPaddleInverted = getAppletParameter("paddleInverted", "false").equals("true");
+		
 		// Display
 		display = new AppleDisplay(this, apple);
 		display.setScale(new Float(getAppletParameter("displayScale", "1")).floatValue());
@@ -129,17 +177,17 @@ public class AppleIIGo extends Applet implements KeyListener, ComponentListener,
 		apple.speaker.setVolume(new Integer(getAppletParameter("speakerVolume", "6")).intValue());
 		
 		// Peripherals
-		disk = new DiskII();
+		disk = new DiskII(apple);
 		apple.setPeripheral(disk, 6);
 
 		// Initialize disk drives
 		diskWritable = getAppletParameter("diskWritable", "false").equals("true");
-		disks0 = getAppletParameter("diskDrive1", "").split("[|]");
-		disk0 = 0;
-		disks1 = getAppletParameter("diskDrive2", "").split("[|]");
-		disk1 = 0;
-		mountDisk(0, disks0[disk0]);
-		mountDisk(1, disks1[disk1]);
+		diskImageNames[0] = getAppletParameter("diskDrive1", "").split("[|]");
+		diskImageNumber[0] = 0;
+		diskImageNames[1] = getAppletParameter("diskDrive2", "").split("[|]");
+		diskImageNumber[1] = 0;
+		mountDisk(0, diskImageNames[0][diskImageNumber[0]]);
+		mountDisk(1, diskImageNames[1][diskImageNumber[1]]);
 
 		// Start CPU
 		if (!isCpuPaused)
@@ -169,8 +217,6 @@ public class AppleIIGo extends Applet implements KeyListener, ComponentListener,
 		unmountDisk(0);
 		unmountDisk(1);
 	}
-	
-
 
 	// Public Java interface
 
@@ -188,9 +234,9 @@ public class AppleIIGo extends Applet implements KeyListener, ComponentListener,
 	public void pause() {
 		debug("pause()");
 		isCpuPaused = true;
-		apple.setPaused(isCpuPaused);
-		display.setPaused(isCpuPaused);
-		apple.speaker.setPaused(isCpuPaused);
+		apple.setPaused(true);
+		display.setPaused(true);
+		apple.speaker.setPaused(true);
 	}
 
 	/**
@@ -199,9 +245,9 @@ public class AppleIIGo extends Applet implements KeyListener, ComponentListener,
 	public void resume() {
 		debug("resume()");
 		isCpuPaused = false;
-		apple.speaker.setPaused(isCpuPaused);
-		display.setPaused(isCpuPaused);
-		apple.setPaused(isCpuPaused);
+		apple.speaker.setPaused(false);
+		display.setPaused(false);
+		apple.setPaused(false);
 	}
 
 	/**
@@ -211,15 +257,57 @@ public class AppleIIGo extends Applet implements KeyListener, ComponentListener,
 		debug("restart()");
 		apple.restart();
 	}
+
+	public void reset() {
+		debug("reset()");
+		apple.reset();
+	}
+
+	public void setSpeed(int value) {
+		debug("setSpeed(" + value + ")");
+		try
+		{
+			pause();
+			this.wait(1000);
+		}
+		catch (Throwable e)
+		{
+		}
+		apple.setCpuSpeed(value);
+		resume();
+	}
+
+	public void cycleDisk(int driveNumber)
+	{
+		debug("cycleDisk(" + driveNumber + ")");
+		if (diskImageNames[driveNumber].length > 1) {
+			diskImageNumber[driveNumber] = ++diskImageNumber[driveNumber] % diskImageNames[driveNumber].length;
+			mountDisk(driveNumber, diskImageNames[driveNumber][diskImageNumber[driveNumber]]);
+		}
+	}
 	
 	/**
 	 * Open input stream
 	 */
 	private DataInputStream openInputStream(String resource) {
+		return openInputStream(resource, null);
+	}
+
+	private DataInputStream openInputStream(String resource, StringBuffer OutFilename) {
 		InputStream is = null;
-		
+
+		if (OutFilename != null)
+		{
+			OutFilename.setLength(0);
+			int slashPos = resource.lastIndexOf('/');
+			int backslashPos = resource.lastIndexOf('\\');
+			int index = Math.max(slashPos, backslashPos);
+			OutFilename.append(resource.substring((index > 0) ? index : 0));
+		}
+
 		try {
-			URL url = new URL(getCodeBase(), resource);
+			URL codeBase = getCodeBase();
+			URL url = new URL(codeBase, resource);
 			debug("resource: " + url.toString());
 
 			is = url.openStream();
@@ -230,7 +318,12 @@ public class AppleIIGo extends Applet implements KeyListener, ComponentListener,
 			else if (resource.toLowerCase().endsWith(".zip"))
 			{
 				is = new ZipInputStream(is);
-				((ZipInputStream)is).getNextEntry();
+				ZipEntry entry = ((ZipInputStream)is).getNextEntry();
+				if (OutFilename != null)
+				{
+					OutFilename.setLength(0);
+					OutFilename.append(entry.getName());
+				}
 			}
 		} catch (Exception e) {
 			debug("Exeption: " + e.getLocalizedMessage());
@@ -288,7 +381,7 @@ public class AppleIIGo extends Applet implements KeyListener, ComponentListener,
 		debug("mountDisk(drive: " + drive + ", resource: " + resource + ")");
 		boolean success = false;
 
-		if ((drive < 0) || (drive > 2))
+		if ((drive < 0) || (drive > 1))
 			return success;
 			
 		try {
@@ -296,9 +389,74 @@ public class AppleIIGo extends Applet implements KeyListener, ComponentListener,
 
 			diskDriveResource[drive] = resource;
 
-			DataInputStream is = openInputStream(resource);
-			success = disk.readDisk(drive, is, 254, false);
+			StringBuffer diskname = new StringBuffer();
+			DataInputStream is = openInputStream(resource, diskname);
+			
+			int diskVolumeNumber = DiskII.DEFAULT_VOLUME;
+			boolean diskWritableOverride = diskWritable;
+
+			// handle disk meta tag for disk volume (etc?)
+			// could break this out into a method, but then multiple tags ...?
+			String lowerDiskname = diskname.toString().toLowerCase();
+			int metaIndex = lowerDiskname.indexOf(metaStart);
+			if (metaIndex != -1)
+			{
+				metaIndex += metaStart.length();
+				int command = 0;
+				int operand = 0;
+				boolean execute = false;
+				while (metaIndex < lowerDiskname.length())
+				{
+					char c = lowerDiskname.charAt(metaIndex++);
+					switch (c)
+					{
+						case '0': case '1':case '2':case '3':case '4':
+						case '5': case '6':case '7':case '8':case '9':
+						{
+							operand = 10 * operand + (c - '0');
+							break;
+						}
+						
+						case '.': // end meta
+							metaIndex = lowerDiskname.length();
+							execute = true;
+							break;
+
+						case '_': // end word
+							execute = true;
+							break;
+							
+						default:
+						{
+							if (c >= 'a' && c <= 'z')
+							{
+								command = (command << 16) + c;
+								execute = (command & 0xFFFF0000) != 0;
+							}
+							break;
+						}
+					}
+					if (execute)
+					{
+						switch (command)
+						{
+							case ('d' << 16) + 'v':
+								diskVolumeNumber = operand;
+								break;
+
+							case ('d' << 16) + 'w':
+								diskWritableOverride = (operand != 0);
+								break;
+						}
+						command = 0;
+						operand = 0;
+					}
+				}
+			}
+			
+			success = disk.readDisk(drive, is, diskname.toString(), !diskWritableOverride, diskVolumeNumber);
 			is.close();
+			showStatus("Drive " + (drive + 1) + ": " + resource);
 		} catch (Exception e) {
 			debug("Exeption: " + e.getLocalizedMessage());
 		}
@@ -311,18 +469,19 @@ public class AppleIIGo extends Applet implements KeyListener, ComponentListener,
 	 */
 	public void unmountDisk(int drive) {
 		debug("unmountDisk(drive: " + drive + ")");
-		if ((drive < 0) || (drive > 2))
+		if ((drive < 0) || (drive > 1))
 			return;
 
 		if (!diskWritable)
 			return;
 			
-		try {
-			OutputStream os = openOutputStream(diskDriveResource[drive]);
-			disk.writeDisk(drive, os);
-			os.close();
-		} catch (Exception e) {
-		}
+		// TODO: only for local disk cache when it's working
+		//try {
+			//OutputStream os = openOutputStream(diskDriveResource[drive]);
+			//disk.writeDisk(drive, os);
+			//os.close();
+		//} catch (Exception e) {
+		//}
 	}
 
 	/**
@@ -333,14 +492,45 @@ public class AppleIIGo extends Applet implements KeyListener, ComponentListener,
 		display.setColorMode(value);
 	}
 
+	/**
+ 	 * Set paddle enabled/disabled
+	 */
+	public void setPaddleEnabled(boolean value) {
+		debug("setPaddleEnabled(value: " + value + ")");
+		isPaddleEnabled = value;
+		if (!value)
+		{
+			apple.paddle.setPaddlePos(0, Paddle.PADDLE_HIGH);
+			apple.paddle.setPaddlePos(1, Paddle.PADDLE_HIGH);
+			apple.paddle.setButton(0, false);
+			apple.paddle.setButton(1, false);
+		}
+	}
+
+	/**
+ 	 * Set paddle inverted/normal
+	 */
+	public void setPaddleInverted(boolean value) {
+		debug("setPaddleInverted(value: " + value + ")");
+		isPaddleInverted = value;
+	}
+
 	/**
  	 * Get disk activity
 	 */
 	public boolean getDiskActivity() {
 		return (!isCpuPaused && disk.isMotorOn());
 	}
-	
-	
+
+	public int getSizeX()
+	{
+		return display.getSizeX();
+	}
+
+	public int getSizeY()
+	{
+		return display.getSizeY();
+	}
 
 	/**
  	 * KeyListener event handling
@@ -360,6 +550,10 @@ public class AppleIIGo extends Applet implements KeyListener, ComponentListener,
 
     public void keyPressed(KeyEvent e) {
 		switch(e.getKeyCode()) {
+			
+		case KeyEvent.VK_META:
+			apple.paddle.setButton(1, true);
+			break;
 		case KeyEvent.VK_ALT:
 			if (e.getKeyLocation() == KeyEvent.KEY_LOCATION_LEFT)
 			{
@@ -427,24 +621,21 @@ public class AppleIIGo extends Applet implements KeyListener, ComponentListener,
 			break;
 		case KeyEvent.VK_HOME:
 			if (e.isControlDown())
-				apple.restart(); 
+				restart();
+			else
+				apple.paddle.setButton(0, true);
+			break;
+		case KeyEvent.VK_END:
+			apple.paddle.setButton(1, true);
 			break;
 		case KeyEvent.VK_F1:
 			showStatus("AppleIIGo Version " + version);
 			break;
 		case KeyEvent.VK_F3:
-			if (disks0.length > 1) {
-				disk0 = ++disk0 % disks0.length;
-				mountDisk(0, disks0[disk0]);
-				showStatus("Disk 1: " + disks0[disk0]);
-			}
+			cycleDisk(0);
 			break;
 		case KeyEvent.VK_F4:
-			if (disks1.length > 1) {
-				disk1 = ++disk1 % disks1.length;
-				mountDisk(1, disks1[disk1]);
-				showStatus("Disk 2: " + disks1[disk1]);
-			}
+			cycleDisk(1);
 			break;
 		case KeyEvent.VK_F5:
 			if (isCpuDebugEnabled)
@@ -466,10 +657,10 @@ public class AppleIIGo extends Applet implements KeyListener, ComponentListener,
 				apple.stepInstructions(128);
 			}
 			break;
-		case KeyEvent.VK_CANCEL: // Ctrl-Pause/Break sends this (N/A on Mac)
+		case KeyEvent.VK_CANCEL: // Pause/Break sends this (as Mac OS swallows Ctrl-F12)
 		case KeyEvent.VK_F12:
 			if (e.isControlDown())
-				apple.reset();
+				reset();
 			break;
 		case KeyEvent.VK_KP_LEFT:
 			handleKeypadLeft();
@@ -488,6 +679,9 @@ public class AppleIIGo extends Applet implements KeyListener, ComponentListener,
 
     public void keyReleased(KeyEvent e) {
 		switch(e.getKeyCode()) {
+		case KeyEvent.VK_META:
+			apple.paddle.setButton(1, false);
+			break;
 		case KeyEvent.VK_ALT:
 			if (e.getKeyLocation() == KeyEvent.KEY_LOCATION_LEFT)
 			{
@@ -505,11 +699,7 @@ public class AppleIIGo extends Applet implements KeyListener, ComponentListener,
 			// else fall through
 		case KeyEvent.VK_KP_LEFT:
 		case KeyEvent.VK_KP_RIGHT:
-			if (isPaddleInverted) {
-				apple.paddle.setPaddlePos(1, 127);
-			} else {
-				apple.paddle.setPaddlePos(0, 127);
-			}
+			handleKeypadCentreX();
 			break;
 		case KeyEvent.VK_UP:
 		case KeyEvent.VK_DOWN:
@@ -518,45 +708,82 @@ public class AppleIIGo extends Applet implements KeyListener, ComponentListener,
 			// else fall through
 		case KeyEvent.VK_KP_UP:
 		case KeyEvent.VK_KP_DOWN:
+			handleKeypadCentreY();
+			break;
+		case KeyEvent.VK_HOME:
+			if (!e.isControlDown())
+			{
+				apple.paddle.setButton(0, false);
+			}
+		case KeyEvent.VK_END:
+			apple.paddle.setButton(1, false);
+		}
+    }
+
+	private void handleKeypadCentreX() {
+		if (isPaddleEnabled)
+		{
+			if (isPaddleInverted) {
+				apple.paddle.setPaddlePos(1, 127);
+			} else {
+				apple.paddle.setPaddlePos(0, 127);
+			}
+		}
+	}
+
+	private void handleKeypadCentreY() {
+		if (isPaddleEnabled)
+		{
 			if (isPaddleInverted) {
 				apple.paddle.setPaddlePos(0, 127);
 			} else {
 				apple.paddle.setPaddlePos(1, 127);
 			}
-			break;
 		}
-    }
+	}
 
 	private void handleKeypadLeft() {
+		if (isPaddleEnabled)
+		{
 			if (isPaddleInverted) {
 				apple.paddle.setPaddlePos(1, 255);
 			} else {
 				apple.paddle.setPaddlePos(0, 0);
 			}
+		}
 	}
 
 	private void handleKeypadRight() {
+		if (isPaddleEnabled)
+		{
 			if (isPaddleInverted) {
 				apple.paddle.setPaddlePos(1, 0);
 			} else {
 				apple.paddle.setPaddlePos(0, 255);
 			}
+		}
 	}
 
 	private void handleKeypadUp() {
+		if (isPaddleEnabled)
+		{
 			if (isPaddleInverted) {
 				apple.paddle.setPaddlePos(0, 255);
 			} else {
 				apple.paddle.setPaddlePos(1, 0);
 			}
+		}
 	}
 
 	private void handleKeypadDown() {
+		if (isPaddleEnabled)
+		{
 			if (isPaddleInverted) {
 				apple.paddle.setPaddlePos(0, 0);
 			} else {
 				apple.paddle.setPaddlePos(1, 255);
 			}
+		}
 	}
 
 	/**
@@ -600,20 +827,24 @@ public class AppleIIGo extends Applet implements KeyListener, ComponentListener,
 
 	public void mousePressed(MouseEvent e) {
 		int modifiers = e.getModifiers();
-		
-		if ((modifiers & InputEvent.BUTTON1_MASK) != 0)
-			apple.paddle.setButton(0, true);
-		if ((modifiers & InputEvent.BUTTON3_MASK) != 0)
-			apple.paddle.setButton(1, true);
+		if (isPaddleEnabled)
+		{
+			if ((modifiers & InputEvent.BUTTON1_MASK) != 0)
+				apple.paddle.setButton(0, true);
+			if ((modifiers & InputEvent.BUTTON3_MASK) != 0)
+				apple.paddle.setButton(1, true);
+		}
 	}
 
 	public void mouseReleased(MouseEvent e) {
 		int modifiers = e.getModifiers();
-		
-		if ((modifiers & InputEvent.BUTTON1_MASK) != 0)
-			apple.paddle.setButton(0, false);
-		if ((modifiers & InputEvent.BUTTON3_MASK) != 0)
-			apple.paddle.setButton(1, false);
+		if (isPaddleEnabled)
+		{
+			if ((modifiers & InputEvent.BUTTON1_MASK) != 0)
+				apple.paddle.setButton(0, false);
+			if ((modifiers & InputEvent.BUTTON3_MASK) != 0)
+				apple.paddle.setButton(1, false);
+		}
 	}
 
 	public void mouseDragged(MouseEvent e) {
@@ -622,12 +853,15 @@ public class AppleIIGo extends Applet implements KeyListener, ComponentListener,
 
 	public void mouseMoved(MouseEvent e) {
 		float scale = display.getScale();
-		if (isPaddleInverted) {
-			apple.paddle.setPaddlePos(0, (int) (255 - e.getY() * 256 / (192 * scale)));
-			apple.paddle.setPaddlePos(1, (int) (255 - e.getX() * 256 / (280 * scale)));
-		} else {
-			apple.paddle.setPaddlePos(0, (int) (e.getX() * 256 / (280 * scale)));
-			apple.paddle.setPaddlePos(1, (int) (e.getY() * 256 / (192 * scale)));
+		if (isPaddleEnabled)
+		{
+			if (isPaddleInverted) {
+				apple.paddle.setPaddlePos(0, (int) (255 - e.getY() * 256 / (192 * scale)));
+				apple.paddle.setPaddlePos(1, (int) (255 - e.getX() * 256 / (280 * scale)));
+			} else {
+				apple.paddle.setPaddlePos(0, (int) (e.getX() * 256 / (280 * scale)));
+				apple.paddle.setPaddlePos(1, (int) (e.getY() * 256 / (192 * scale)));
+			}
 		}
 	}
 
@@ -643,5 +877,5 @@ public class AppleIIGo extends Applet implements KeyListener, ComponentListener,
 	 */
 	public void update(Graphics g) {
 		display.paint(g);
-	}	
+	}
 }

Source/AppleSpeaker.java

@@ -2,7 +2,7 @@
 /**
  * AppleIIGo
  * Speaker processing
- * (C) 2006 by Marc S. Ressl(ressl@lonetree.com)
+ * Copyright 2006 by Marc S. Ressl(mressl@gmail.com)
  * Released under the GPL
  */
 
@@ -13,7 +13,7 @@ public class AppleSpeaker implements Runnable {
 	private EmAppleII apple;
 
 	// Refresh
-	private int refreshRate;
+//	private int refreshRate;
 	private long refreshInterval;
 
 	// Sound stuff
@@ -58,7 +58,7 @@ public class AppleSpeaker implements Runnable {
 		if (value <= 0.0f)
 			return;
 			
-		this.refreshRate = value;
+//		this.refreshRate = value;
 		refreshInterval = (int) (1000.0 / value);
 
 		speakerClocksPerSample = (int) (apple.getCpuSpeed() * 1000.0f / SPEAKER_SAMPLERATE);
@@ -67,9 +67,9 @@ public class AppleSpeaker implements Runnable {
 	/**
 	 * Get refresh rate
 	 */
-	private int getRefreshRate() {
-		return refreshRate;
-	}
+//	private int getRefreshRate() {
+//		return refreshRate;
+//	}
 	
 	/**
 	 * Set speaker volume
@@ -120,7 +120,7 @@ public class AppleSpeaker implements Runnable {
 				SPEAKER_BIGENDIAN);
 
 			DataLine.Info info = new DataLine.Info(
-				DataLine.class,
+				SourceDataLine.class,
 				audioFormat);
 
 			try {

Source/DiskII.java

@@ -2,7 +2,8 @@
 /**
  * AppleIIGo
  * Disk II Emulator
- * (C) 2006 by Marc S. Ressl(ressl@lonetree.com)
+ * Copyright 2015 by Nick Westgate (Nick.Westgate@gmail.com)
+ * Copyright 2006 by Marc S. Ressl(mressl@gmail.com)
  * Released under the GPL
  * Based on work by Doug Kwan
  */
@@ -31,17 +32,23 @@ public class DiskII extends Peripheral {
 	};	
 
 	// Constants
+	public static final int DEFAULT_VOLUME = 254;
 	private static final int NUM_DRIVES = 2;
 	private static final int DOS_NUM_SECTORS = 16;
 	private static final int DOS_NUM_TRACKS = 35;
+	private static final int MAX_PHYS_TRACK = (2 * DOS_NUM_TRACKS) - 1;
 	private static final int DOS_TRACK_BYTES = 256 * DOS_NUM_SECTORS;
-	private static final int RAW_TRACK_BYTES = 6250;
+	private static final int RAW_TRACK_BYTES = 0x1A00; // 0x1A00 (6656) for .NIB (was 6250)
+	private static final int STANDARD_2IMG_HEADER_ID = 0x32494D47;
+	private static final int STANDARD_2IMG_HEADER_SIZE = 64;
+	private static final int STANDARD_PRODOS_BLOCKS = 280;
 	
 	// Disk II direct access variables
 	private int drive = 0;
+	private int phases = 0;
 	private boolean isMotorOn = false;
 
-	private byte[][][] disk = new byte[NUM_DRIVES][DOS_NUM_TRACKS][];
+	private byte[][][] diskData = new byte[NUM_DRIVES][DOS_NUM_TRACKS][];
 	private boolean[] isWriteProtected = new boolean[NUM_DRIVES];
 
 	private int currPhysTrack;
@@ -64,9 +71,10 @@ public class DiskII extends Peripheral {
 	 */
 
 	// Internal registers
-	private int latchAddress;
 	private int latchData;
 	private boolean writeMode;
+	private boolean loadMode;
+	private int driveSpin;
 	
 	// GCR encoding and decoding tables
 	private static final int[] gcrEncodingTable = {
@@ -79,30 +87,36 @@ public class DiskII extends Peripheral {
 		0xED, 0xEE, 0xEF, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6,
 		0xF7, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF,
 	};
-	private int[] gcrDecodingTable = new int[256];
+	//private int[] gcrDecodingTable = new int[256];
 	private int[] gcrSwapBit = {0, 2, 1, 3};
 	private int[] gcrBuffer = new int[256];
 	private int[] gcrBuffer2 = new int[86];
 	
 	// Physical sector to DOS 3.3 logical sector table
-	private static final int[] gcrLogicalSector = {
+	private static final int[] gcrLogicalDos33Sector = {
 		0x0, 0x7, 0xE, 0x6, 0xD, 0x5, 0xC, 0x4,
 		0xB, 0x3, 0xA, 0x2, 0x9, 0x1, 0x8, 0xF };
 	
+	// Physical sector to DOS 3.3 logical sector table
+	private static final int[] gcrLogicalProdosSector = {
+		0x0, 0x8, 0x1, 0x9, 0x2, 0xA, 0x3, 0xB,
+		0x4, 0xC, 0x5, 0xD, 0x6, 0xE, 0x7, 0xF };
+	
 	// Temporary variables for conversion
 	private byte[] gcrNibbles = new byte[RAW_TRACK_BYTES];
 	private int gcrNibblesPos;
 	
-	
-		
+	EmAppleII apple;
+
 	/**
 	 * Constructor
 	 */
-	public DiskII() {
+	public DiskII(EmAppleII apple) {
 		super();
+		this.apple = apple;
 		
-		readDisk(0, null, 254, false);
-		readDisk(1, null, 254, false);
+		readDisk(0, null, "", false, DEFAULT_VOLUME);
+		readDisk(1, null, "", false, DEFAULT_VOLUME);
 	}
 	
 	/**
@@ -111,100 +125,54 @@ public class DiskII extends Peripheral {
 	 * @param	address	Address
 	 */
 	public int ioRead(int address) {
-		int phase;
-		
 		switch (address & 0xf) {
 			case 0x0:
-			case 0x2:			
-			case 0x4:
-			case 0x6:
-				// Q0, Q1, Q2, Q3 off
-				break;
 			case 0x1:
-				// Q0 on
-				phase = currPhysTrack & 3;
-				if (phase == 1) {
-					if (currPhysTrack > 0)
-						currPhysTrack--;
-				} else if (phase == 3) {
-					if (currPhysTrack < ((2 * DOS_NUM_TRACKS) - 1))
-						currPhysTrack++;
-				}
-				realTrack = disk[drive][currPhysTrack >> 1];
-				break;
+			case 0x2:			
 			case 0x3:
-				// Q1 on
-				phase = currPhysTrack & 3;
-				if (phase == 2) {
-					if (currPhysTrack > 0)
-						currPhysTrack--;
-				} else if (phase == 0) {
-					if (currPhysTrack < ((2 * DOS_NUM_TRACKS) - 1))
-						currPhysTrack++;
-				}
-				realTrack = disk[drive][currPhysTrack >> 1];
-				break;
+			case 0x4:
 			case 0x5:
-				// Q2 on
-				phase = currPhysTrack & 3;
-				if (phase == 3) {
-					if (currPhysTrack > 0)
-						currPhysTrack--;
-				} else if (phase == 1) {
-					if (currPhysTrack < ((2 * DOS_NUM_TRACKS) - 1))
-						currPhysTrack++;
-				}
-				realTrack = disk[drive][currPhysTrack >> 1];
-				break;
+			case 0x6:
 			case 0x7:
-				// Q3 on
-				phase = currPhysTrack & 3;
-				if (phase == 0) {
-					if (currPhysTrack > 0)
-						currPhysTrack--;
-				} else if (phase == 2) {
-					if (currPhysTrack < ((2 * DOS_NUM_TRACKS) - 1))
-						currPhysTrack++;
-				}
-				realTrack = disk[drive][currPhysTrack >> 1];
+				setPhase(address);
 				break;
 			case 0x8:
-				// Motor off
 				isMotorOn = false;
 				break;
 			case 0x9:
-				// Motor on
 				isMotorOn = true;
 				break;
 			case 0xa:
-				// Drive 1
-				driveCurrPhysTrack[drive] = currPhysTrack;
-				drive = 0;
-				currPhysTrack = driveCurrPhysTrack[drive];
-
-				realTrack = disk[drive][currPhysTrack >> 1];
+				setDrive(0);
 				break;
 			case 0xb:
-				// Drive 2
-				driveCurrPhysTrack[drive] = currPhysTrack;
-				drive = 1;
-				currPhysTrack = driveCurrPhysTrack[drive];
-
-				realTrack = disk[drive][currPhysTrack >> 1];
+				setDrive(1);
 				break;
 			case 0xc:
-				return ioLatchC();
+				ioLatchC();
+				break;
 			case 0xd:
-				ioLatchD(0xff);
+				loadMode = true;
+				if (isMotorOn && !writeMode)
+				{
+					latchData &= 0x7F;
+					// TODO: check phase - write protect is forced if phase 1 is on [F9.7]
+					if (isWriteProtected[drive])
+					{
+						latchData |= 0x80;
+					}
+				}
 				break;
 			case 0xe:
-				return ioLatchE();
+				writeMode = false;
+				break;
 			case 0xf:
-				ioLatchF(0xff);
+				writeMode = true;
 				break;
 		}
 		
-		return rand.nextInt(256);
+		// only even addresses return the latch
+		return ((address & 1) == 0) ? latchData : rand.nextInt(256); // TODO: floating bus
     }
 	
 	/**
@@ -222,25 +190,39 @@ public class DiskII extends Peripheral {
 			case 0x5:
 			case 0x6:
 			case 0x7:
+				setPhase(address);
+				break;
 			case 0x8:
+				isMotorOn = false;
+				break;
 			case 0x9:
+				isMotorOn = true;
+				break;
 			case 0xa:
+				setDrive(0);
+				break;
 			case 0xb:
-				ioRead(address);
+				setDrive(1);
 				break;
 			case 0xc:
 				ioLatchC();
 				break;
 			case 0xd:
-				ioLatchD(value);
+				loadMode = true;
 				break;
 			case 0xe:
-				ioLatchE();
+				writeMode = false;
 				break;
 			case 0xf:
-				ioLatchF(value);
+				writeMode = true;
 				break;
 		}
+		
+		if (isMotorOn && writeMode && loadMode)
+		{
+			// any address writes latch for sequencer LD; OE1/2 irrelevant ['323 datasheet]
+			latchData = value;
+		}
     }
 	
 	/**
@@ -256,29 +238,88 @@ public class DiskII extends Peripheral {
 	 * Reset peripheral
 	 */
 	public void reset() {
-		ioRead(0x8);
+		drive = 0;
+		isMotorOn = false;
+		loadMode = false;
+		writeMode = false;
 	}
 
 	/**
  	 * Loads a disk
-	 *
-	 * @param	is			InputStream
-	 * @param	drive		Disk II drive
 	 */
-	public boolean readDisk(int drive, DataInputStream is, int volume, boolean isWriteProtected) {
-		byte[] track = new byte[RAW_TRACK_BYTES];
-
+	public boolean readDisk(int drive, DataInputStream is, String name, boolean isWriteProtected, int volumeNumber) {
 		try {
+			byte[] track = new byte[DOS_TRACK_BYTES];
+			boolean proDos = false;
+			boolean nib = false;
+		
+			String lowerName = name.toLowerCase();
+			if (lowerName.indexOf(".2mg") != -1 || lowerName.indexOf(".2img") != -1)
+			{
+				// 2IMG, so check if we can handle it
+				byte[] header = new byte[STANDARD_2IMG_HEADER_SIZE];
+				is.readFully(header, 0, STANDARD_2IMG_HEADER_SIZE);
+
+				int id = (header[0x00] << 24) | (header[0x01] << 16) | (header[0x02] << 8) | (header[0x03]);
+				if (id != STANDARD_2IMG_HEADER_ID)
+					return false;
+
+				int headerSize = (header[0x09] << 8) | (header[0x08]);
+				if (headerSize != STANDARD_2IMG_HEADER_SIZE)
+					return false;
+				
+				int format = (header[0x0F] << 24) | (header[0x0E] << 16) | (header[0x0D] << 8) | (header[0x0C]);
+				if (format == 1)
+				{
+					proDos = true;
+					int blocks = (header[0x17] << 24) | (header[0x16] << 16) | (header[0x15] << 8) | (header[0x14]);
+					if (blocks != STANDARD_PRODOS_BLOCKS)
+						return false; // only handle standard 5.25 inch images
+				}
+				else if (format == 2)
+				{
+					nib = true;
+				}
+				else if (format != 0)
+				{
+					return false; // if not ProDOS, NIB or DSK
+				}
+				
+				// use write protected and volume number if present
+				int flags = (header[0x13] << 24) | (header[0x12] << 16) | (header[0x11] << 8) | (header[0x10]);
+				if ((flags & (1 << 31)) != 0)
+				{
+					isWriteProtected = true; // only override if set 
+				}
+				if ((flags & (1 << 8)) != 0)
+				{
+					volumeNumber = (flags & 0xFF);
+				}
+			}
+			else
+			{
+				// check for PO and NIB in the name
+				proDos = lowerName.indexOf(".po") != -1;
+				nib = lowerName.indexOf(".nib") != -1;
+			}
+
 			for (int trackNum = 0; trackNum < DOS_NUM_TRACKS; trackNum++) {
-				disk[drive][trackNum] = new byte[RAW_TRACK_BYTES];
+				diskData[drive][trackNum] = new byte[RAW_TRACK_BYTES];
 
 				if (is != null) {
-					is.readFully(track, 0, DOS_TRACK_BYTES);
-					trackToNibbles(track, disk[drive][trackNum], volume, trackNum);
+					if (nib)
+					{
+						is.readFully(diskData[drive][trackNum], 0, RAW_TRACK_BYTES);
+					}
+					else
+					{
+						is.readFully(track, 0, DOS_TRACK_BYTES);
+						trackToNibbles(track, diskData[drive][trackNum], volumeNumber, trackNum, !proDos);
+					}
 				}
 			}
 
-			this.realTrack = disk[drive][currPhysTrack >> 1];
+			this.realTrack = diskData[drive][currPhysTrack >> 1];
 			this.isWriteProtected[drive] = isWriteProtected;
 			
 			return true;
@@ -305,68 +346,112 @@ public class DiskII extends Peripheral {
 		return isMotorOn;
 	}
 
+	private void ioLatchC() {
+		loadMode = false;
+		if (!writeMode)
+		{
+			if (!isMotorOn)
+			{
+				// simple hack to fool RWTS SAMESLOT drive spin check (usually at $BD34)
+				driveSpin = (driveSpin + 1) & 0xF;
+				if (driveSpin == 0)
+				{
+					latchData = 0x7F;
+					return;
+				}
+			}
 
-
-	/**
-	 * I/O read Latch C
-	 *
-	 * @param	address	Address
-	 */
-	private int ioLatchC() {
-		if (writeMode)
-			// Write data: C0xD, C0xC
-			realTrack[currNibble] = (byte) latchData;
-		else
 			// Read data: C0xE, C0xC
 			latchData = (realTrack[currNibble] & 0xff);
 
+			// is RWTS looking for an address prologue? (RDADR)
+			if (/* fastDisk && */ // TODO: fastDisk property to enable/disable 
+				apple.memoryRead(apple.PC + 3) == 0xD5 && // #$D5
+				apple.memoryRead(apple.PC + 2) == 0xC9 && // CMP (usually at $B94F)
+				apple.memoryRead(apple.PC + 1) == 0xFB && // PC - 3
+				apple.memoryRead(apple.PC + 0) == 0x10 &&  // BPL
+				latchData != 0xD5) 
+			{
+				// Y: find the next address prologues
+				int count = RAW_TRACK_BYTES / 16;
+				do
+				{
+					currNibble++;
+					if (currNibble >= RAW_TRACK_BYTES)
+						currNibble = 0;
+					latchData = (realTrack[currNibble] & 0xff);
+				}
+				while (latchData != 0xD5 && --count > 0);
+			}
+			// N: skip invalid nibbles we padded the track buffer with 
+			else if (latchData == 0x7F)
+			{
+				int count = RAW_TRACK_BYTES / 16;
+				do
+				{
+					currNibble++;
+					if (currNibble >= RAW_TRACK_BYTES)
+						currNibble = 0;
+					latchData = (realTrack[currNibble] & 0xff);
+				}
+				while (latchData == 0x7F && --count > 0);
+			}
+		}
+		else
+		{
+			// Write data: C0xD, C0xC
+			realTrack[currNibble] = (byte) latchData;
+		}
+
 		currNibble++;
 		if (currNibble >= RAW_TRACK_BYTES)
 			currNibble = 0;
+	}
 
-		latchAddress = 0xc;
-		return latchData;
-	}
-	
-	/**
-	 * I/O write Latch D
-	 *
-	 * @param	address	Address
-	 */
-	private void ioLatchD(int value) {
-		// Prepare write
-		writeMode = true;
-		latchData = value;
-		latchAddress = 0xd;
-	}
-	
-	/**
-	 * I/O read Latch E
-	 *
-	 * @param	address	Address
-	 */
-	private int ioLatchE() {
-		// Read write-protect: C0xD, C0xE
-		if (latchAddress == 0xd) {
-			latchAddress = 0xe;
-			return isWriteProtected[drive] ? 0x80 : 0x00;
+	private void setPhase(int address) {
+		int phase = (address >> 1) & 3;
+		int phase_bit = (1 << phase);
+
+		// update the magnet states
+		if ((address & 1) != 0)
+		{
+			// phase on
+			phases |= phase_bit;
+		}
+		else
+		{
+			// phase off
+			phases &= ~phase_bit;
 		}
 
-		writeMode = false;
-		latchAddress = 0xe;
-		return 0x3c;
+		// check for any stepping effect from a magnet
+		// - move only when the magnet opposite the cog is off
+		// - move in the direction of an adjacent magnet if one is on
+		// - do not move if both adjacent magnets are on
+		// momentum and timing are not accounted for ... maybe one day!
+		int direction = 0;
+		if ((phases & (1 << ((currPhysTrack + 1) & 3))) != 0)
+			direction += 1;
+		if ((phases & (1 << ((currPhysTrack + 3) & 3))) != 0)
+			direction -= 1;
+
+		// apply magnet step, if any
+		if (direction != 0)
+		{
+			currPhysTrack += direction;
+			if (currPhysTrack < 0)
+				currPhysTrack = 0;
+			else if (currPhysTrack > MAX_PHYS_TRACK)
+				currPhysTrack = MAX_PHYS_TRACK;
+		}
+		realTrack = diskData[drive][currPhysTrack >> 1];
 	}
 
-	/**
-	 * I/O write Latch F
-	 *
-	 * @param	address	Address
-	 */
-	private void ioLatchF(int value) {
-		// Prepare write
-		writeMode = true;
-		latchData = value;
-		latchAddress = 0xf;
+	private void setDrive(int newDrive) {
+		driveCurrPhysTrack[drive] = currPhysTrack;
+		drive = newDrive;
+		currPhysTrack = driveCurrPhysTrack[drive];
+		realTrack = diskData[drive][currPhysTrack >> 1];
 	}
 
 	/**
@@ -384,15 +469,24 @@ public class DiskII extends Peripheral {
 	}
 
 	/**
- 	 * Writes sync bits
+ 	 * Writes nibbles
+	 *
+	 * @param	length		Number of bits
+	 */
+	private final void writeNibbles(int nibble, int length) {
+		while(length > 0) {
+			length--;
+			gcrWriteNibble(nibble);
+		}
+	}
+
+	/**
+ 	 * Writes sync nibbles
 	 *
 	 * @param	length		Number of bits
 	 */
 	private final void writeSync(int length) {
-		while(length > 0) {
-			length--;
-			gcrWriteNibble(0xff);
-		}
+		writeNibbles(0xff, length);
 	}
 
 	/**
@@ -487,17 +581,18 @@ public class DiskII extends Peripheral {
 	/**
  	 * Converts a track to nibbles
 	 */
-	private void trackToNibbles(byte[] track, byte[] nibbles, int volumeNum, int trackNum) {
+	private void trackToNibbles(byte[] track, byte[] nibbles, int volumeNum, int trackNum, boolean dos) {
 		this.gcrNibbles = nibbles;
 		gcrNibblesPos = 0;
+		int logicalSector[] = (dos) ? gcrLogicalDos33Sector : gcrLogicalProdosSector;
 
 		for (int sectorNum = 0; sectorNum < DOS_NUM_SECTORS; sectorNum++) {
-			encode62(track, gcrLogicalSector[sectorNum] << 8);
+			encode62(track, logicalSector[sectorNum] << 8);
 			writeSync(12);
 			writeAddressField(volumeNum, trackNum, sectorNum);
 			writeSync(8);
 			writeDataField();
 		}
-		writeSync(RAW_TRACK_BYTES - gcrNibblesPos);
+		writeNibbles(0x7F, RAW_TRACK_BYTES - gcrNibblesPos); // invalid nibbles to skip on read
 	}
 }

Source/Em6502.java

@@ -1,12 +1,14 @@
+import java.io.PrintWriter;
+
 
 /**
  * AppleIIGo
  * Apple II Emulator for J2SE
- * (C) 2006 by Marc S. Ressl(ressl@lonetree.com)
+ * Copyright 2006 by Marc S. Ressl(mressl@gmail.com)
  * Released under the GPL
  * Adapted from code by Doug Kwan
  * Adapted from code by Randy Frank randy@tessa.iaf.uiowa.edu
- * Adapted from code (C) 1989 Ben Koning [556498717 408/738-1763 ben@apple.com]
+ * Adapted from code Copyright 1989 Ben Koning [556498717 408/738-1763 ben@apple.com]
  */
 
 public class Em6502 {
@@ -78,6 +80,7 @@ public class Em6502 {
 	public static final int FLAG_I = (1 << 2);
 	public static final int FLAG_D = (1 << 3);
 	public static final int FLAG_B = (1 << 4);
+	public static final int FLAG_R = (1 << 5);
 	public static final int FLAG_V = (1 << 6);
 	public static final int FLAG_N = (1 << 7);
 	/*
@@ -119,7 +122,9 @@ public class Em6502 {
 	/**
 	 * Constructor
 	 */
-	public void Em6502() {
+	public Em6502() {
+//		createRunFile(); // TODO: for debugging - disable
+		
 		// Init BCD tables
 		BCDTableAdd = new int[512];
 		BCDTableSub = new int[512];
@@ -133,6 +138,10 @@ public class Em6502 {
 			BCDTableSub[i] = ((i & 0x0f) <= 0x09) ? i : (i - 0x06);
 			BCDTableSub[i] -= ((BCDTableSub[i] & 0xf0) <= 0x90) ? 0 : 0x60;
 		}
+
+		// Init CPU
+        S = 0xFF;
+		P = FLAG_B | FLAG_R;
 	}
 	
 	/*
@@ -154,14 +163,14 @@ public class Em6502 {
 	 */
 	private final void setN(boolean b) {if (b) P |= FLAG_N; else P &= ~FLAG_N;}
 	private final void setV(boolean b) {if (b) P |= FLAG_V; else P &= ~FLAG_V;}
-	private final void setB(boolean b) {if (b) P |= FLAG_B; else P &= ~FLAG_B;}
+//	private final void setB(boolean b) {if (b) P |= FLAG_B; else P &= ~FLAG_B;}
 	private final void setD(boolean b) {if (b) P |= FLAG_D; else P &= ~FLAG_D;}
 	private final void setI(boolean b) {if (b) P |= FLAG_I; else P &= ~FLAG_I;}
 	private final void setZ(boolean b) {if (b) P |= FLAG_Z; else P &= ~FLAG_Z;}
 	private final void setC(boolean b) {if (b) P |= FLAG_C; else P &= ~FLAG_C;}
 	private final boolean getN() {return ((P & FLAG_N) != 0);}
 	private final boolean getV() {return ((P & FLAG_V) != 0);}
-	private final boolean getB() {return ((P & FLAG_B) != 0);}
+//	private final boolean getB() {return ((P & FLAG_B) != 0);}
 	private final boolean getD() {return ((P & FLAG_D) != 0);}
 	private final boolean getI() {return ((P & FLAG_I) != 0);}
 	private final boolean getZ() {return ((P & FLAG_Z) != 0);}
@@ -183,11 +192,11 @@ public class Em6502 {
 	private final void setFC(boolean c) {result = (c ? 0x100 : 0x00);}
 
 	/*
-	 * Macro for page crossing cycle regulation
+	 * Macro for page crossing cycle regulation - TODO: Why not used!? CPU probably not cycle accurate.
 	 */
-	private final void checkCrossPage(int addr, int offset) {
-		if ((((addr + offset) ^ addr) & 0xff00) != 0) clock++;
-	}
+//	private final void checkCrossPage(int addr, int offset) {
+//		if ((((addr + offset) ^ addr) & 0xff00) != 0) clock++;
+//	}
 	
 	/*
 	 * Macros for effective address calculation 
@@ -232,9 +241,9 @@ public class Em6502 {
 		// return easp1 + Y;
 		return eaabs() + Y;
 	}
-	private final int eaabsyNC() {
-		return eaabs() + Y;
-	}
+//	private final int eaabsyNC() {
+//		return eaabs() + Y;
+//	}
 
 	/*
 	 * Indirect addressing
@@ -258,11 +267,11 @@ public class Em6502 {
 		// return easp2 + Y;
 		return easp2 + (zeroPageRead((easp1 + 1) & 0xff) << 8) + Y;
 	}
-	private final int eazpindyNC() {
-		easp1 = eaimm();
-		easp2 = zeroPageRead(easp1);
-		return easp2 + (zeroPageRead((easp1 + 1) & 0xff) << 8) + Y;
-	}
+//	private final int eazpindyNC() {
+//		easp1 = eaimm();
+//		easp2 = zeroPageRead(easp1);
+//		return easp2 + (zeroPageRead((easp1 + 1) & 0xff) << 8) + Y;
+//	}
 
 	/*
 	 * New 65C02 addressing mode
@@ -294,9 +303,48 @@ public class Em6502 {
 		clock++;
 	}
 
+//	private PrintWriter runFile;
+//	private boolean runFlag = false;
+//
+//	private void createRunFile()
+//	{
+//		try
+//		{
+//			//runFile = new PrintWriter("C:\\Dev\\Emulators\\AppleIIGo\\AppleIIGoRun.txt");
+//		}
+//		catch (Exception ex)
+//		{
+//			// swallow
+//		}
+//	}
+//
+//	private final void writeRunFile(int opcode)
+//	{
+//		if (PC == 0x2000)
+//			runFlag = true;
+//		if (
+//				runFlag &&
+//				(PC > 0x1000)
+//				&&
+//				(PC < 0xC000)
+//			)
+//		{
+//			if (runFile != null)
+//			{
+//				setN(getFN());
+//				setZ(getFZ());
+//				setC(getFC());
+//
+//				runFile.printf("%04X-%02X P=%02X A=%02X\r\n", PC, opcode, P, A);
+//				runFile.flush();
+//			}
+//		}
+//	}
+	
 	/** This executes a single instruction. */
 	private final void executeInstruction() {
 		opcode = memoryRead(PC);
+//		writeRunFile(opcode); // TODO: for debugging = disable
 		PC++;
 		
 		switch(opcode) {
@@ -530,13 +578,13 @@ public class Em6502 {
 			break;
 			
 		case 0x00:	// BRK
+			PC++;
 			push(PC >> 8);	// save PCH, PCL & P
 			push(PC);
 			setN(getFN());
 			setZ(getFZ());
 			setC(getFC());
-			setB(true);
-			push(P);
+			push(P); // B and R always set
 			setI(true);
 			PC = memoryRead(0xfffe);
 			PC |= memoryRead(0xffff) << 8;
@@ -1043,7 +1091,7 @@ public class Em6502 {
 			break;
 			
 		case 0x28:	// PLP
-			P = pop() | 0x20; // fix bug in bit5 of P
+			P = pop() | FLAG_B | FLAG_R; // B and R always set
 			setFC(getC());
 			setFNZ(getN(), getZ());
 			clock += 4;
@@ -1144,7 +1192,7 @@ public class Em6502 {
 			break;
 			
 		case 0x40:	// RTI
-			P = pop() | 0x20; // bit 5 bug of 6502
+			P = pop() | FLAG_B | FLAG_R; // B and R always set
 			setFC(getC());
 			setFNZ(getN(), getZ());
 			PC = pop();	// splitting is necessary
@@ -1539,6 +1587,9 @@ public class Em6502 {
 		default:	// unknown instructions
 			clock += 2;
 		}
+		
+//		if (PC == 0xB30)
+//			throw (new RuntimeException()); // TODO: for breakpoint hack - disable
 	}
 	
 	public final int executeInstructions(int num) {
@@ -1567,13 +1618,13 @@ public class Em6502 {
 		if ((exceptionRegister & SIG_6502_RESET) != 0) {
 			onReset();
 			
-			PC = memoryRead(0xfffc);
-			PC |= (memoryRead(0xfffd) << 8);
-			S = (S - 3) & 0xff;
-			setI(true);
 			setD(false); // not on NMOS 6502
 			setFC(getC());
 			setFNZ(getN(), getZ());
+			S = (S - 3) & 0xff;
+			setI(true);
+			PC = memoryRead(0xfffc);
+			PC |= (memoryRead(0xfffd) << 8);
 			clock += 7;
 			exceptionRegister &= ~SIG_6502_RESET;
 		}
@@ -1587,7 +1638,8 @@ public class Em6502 {
 			setN(getFN());
 			setZ(getFZ());
 			setC(getFC());
-			push(P);
+			push(P & ~FLAG_B);
+			setI(true);
 			PC = memoryRead(0xfffa);
 			PC |= memoryRead(0xfffb) << 8;
 			clock += 7;
@@ -1605,8 +1657,7 @@ public class Em6502 {
 				setN(getFN());
 				setZ(getFZ());
 				setC(getFC());
-				setB(false);
-				push(P);
+				push(P & ~FLAG_B);
 				setI(true);
 				PC = memoryRead(0xfffe);
 				PC |= memoryRead(0xffff) << 8;

Source/EmAppleII.java

@@ -2,7 +2,7 @@
 /**
  * AppleIIGo
  * Apple II Emulator for J2ME
- * (C) 2006 by Marc S. Ressl(ressl@lonetree.com)
+ * Copyright 2006 by Marc S. Ressl(mressl@gmail.com)
  * Released under the GPL
  */
 
@@ -74,8 +74,9 @@ public class EmAppleII extends Em6502 implements Runnable {
 	public static final int GR_DHIRES	= (1 << 7);
 
 	// Sound
-	public static final int SPEAKER_FLIPS_SIZE = 4096;
-	public static final int SPEAKER_FLIPS_MASK = 4095;
+	public static final int SPEAKER_FLIPS_BITS = 12;
+	public static final int SPEAKER_FLIPS_SIZE = 1 << SPEAKER_FLIPS_BITS;
+	public static final int SPEAKER_FLIPS_MASK = SPEAKER_FLIPS_SIZE - 1;
 	
 	public int speakerFlips[] = new int[SPEAKER_FLIPS_SIZE];
 	public int speakerFlipsPointer = 0;
@@ -188,7 +189,7 @@ public class EmAppleII extends Em6502 implements Runnable {
  	 * Apple II class constructor
 	 */
 	public EmAppleII() {
-		Em6502();
+		super();
 		
 		// Allocate compute memory
 		mem = new byte[MEM_END];
@@ -263,6 +264,17 @@ public class EmAppleII extends Em6502 implements Runnable {
 		System.arraycopy(rom, offset + 0x3000, mem, MEM_ROM_INTERNAL + 0x00000, 0x01000);
 		System.arraycopy(rom, offset + 0x3800, mem, MEM_ROM_EXTERNAL + 0x00800, 0x00800);
 
+		for (int slot = 0x100; slot <= 0x700; slot += 0x100)
+		{
+			if (mem[MEM_ROM_EXTERNAL + slot] == 0)
+			{
+				// 0 data is a bad default for empty external slots (e.g. Mabel's Mansion reboots)
+				// so ideally we would emulate the floating bus, but for now we just hardcode 0xA0
+				for (int i = 0; i <= 0xFF; i++)
+					mem[MEM_ROM_EXTERNAL + slot + i] = (byte)0xA0;
+			}
+		}
+
 		return true;
 	}
 
@@ -1126,6 +1138,7 @@ public class EmAppleII extends Em6502 implements Runnable {
 				
 				checkInterrupts();
 
+//				try {
 				if (isStepMode) {
 					if (isNextStep) {
 						isNextStep = false;
@@ -1136,6 +1149,11 @@ public class EmAppleII extends Em6502 implements Runnable {
 					while (clocksNeeded > 0)
 						clocksNeeded -= executeInstructions(1 + (clocksNeeded >> 3));
 				}
+//				}
+//				catch (RuntimeException e)
+//				{
+//					setStepMode(true); // TODO: for breakpoint hack - disable
+//				}
 
 				// TODO: need something like the following for fast disk access
 				//if (slots[6] instanceof DiskII && !((DiskII)slots[6]).isMotorOn())

Source/Paddle.java

@@ -2,7 +2,7 @@
 /**
 * AppleIIGo
  * Apple II Emulator for J2ME
- * (C) 2006 by Marc S. Ressl(ressl@lonetree.com)
+ * Copyright 2006 by Marc S. Ressl(mressl@gmail.com)
  * Released under the GPL
  */
 
@@ -22,7 +22,7 @@ public class Paddle {
 	private int[] buttonRegister = new int[4];
 
 	// Paddle variables
-	private int paddleMode;
+	// private int paddleMode; // TODO: Was this for analog/digital mode? (Nick)
 
 	private int[] paddleClockEvent = new int[4];
 	private int[] paddleClockInc = new int[4];
@@ -35,10 +35,10 @@ public class Paddle {
 	public Paddle(EmAppleII apple) {
 		this.apple = apple;
 
-		setPaddlePos(0, PADDLE_CENTER);
-		setPaddlePos(1, PADDLE_CENTER);
-		setPaddlePos(2, PADDLE_CENTER);
-		setPaddlePos(3, PADDLE_CENTER);
+		setPaddlePos(0, PADDLE_HIGH);
+		setPaddlePos(1, PADDLE_HIGH);
+		setPaddlePos(2, PADDLE_HIGH);
+		setPaddlePos(3, PADDLE_HIGH);
 	}
 	
 	/**

Source/Peripheral.java

@@ -2,7 +2,7 @@
 /**
  * AppleIIGo
  * Slot interface
- * (C) 2006 by Marc S. Ressl(ressl@lonetree.com)
+ * Copyright 2006 by Marc S. Ressl(mressl@gmail.com)
  * Released under the GPL
  * Based on work by Steven E. Hugg
  */