character ROM display

src/com/bytezone/diskbrowser/applefile/CharacterRom.java

@@ -0,0 +1,109 @@
+package com.bytezone.diskbrowser.applefile;
+
+import java.awt.AlphaComposite;
+import java.awt.Graphics2D;
+import java.awt.image.BufferedImage;
+import java.awt.image.DataBuffer;
+import java.util.ArrayList;
+import java.util.List;
+
+public class CharacterRom extends AbstractFile
+{
+  String description;
+  List<Character> characters = new ArrayList<> ();
+
+  public CharacterRom (String name, byte[] buffer)
+  {
+    super (name, buffer);
+
+    description = new String (buffer, 16, 16);
+
+    int gapX = 4;
+    int gapY = 4;
+    int sizeX = 7;
+    int sizeY = 8;
+    int marginX = 2;
+    int marginY = 2;
+
+    image = new BufferedImage (8 * (sizeX + gapX), 12 * (sizeY + gapY),
+        BufferedImage.TYPE_BYTE_GRAY);
+    Graphics2D g2d = image.createGraphics ();
+    g2d.setComposite (AlphaComposite.getInstance (AlphaComposite.SRC_OVER, (float) 1.0));
+
+    int x = marginX;
+    int y = marginY;
+    int count = 0;
+    int ptr = 256;
+
+    while (ptr < buffer.length)
+    {
+      Character character = new Character (buffer, ptr);
+      characters.add (character);
+      ptr += 8;
+
+      g2d.drawImage (character.image, x, y, null);
+      x += sizeX + gapX;
+      if (++count % 8 == 0)
+      {
+        x = marginX;
+        y += sizeY + gapY;
+      }
+    }
+    g2d.dispose ();
+  }
+
+  @Override
+  public String getText ()
+  {
+    StringBuilder text = new StringBuilder (description + "\n\n");
+    for (int i = 256; i < buffer.length; i += 8)
+    {
+      for (int line = 0; line < 8; line++)
+      {
+        int value = buffer[i + line] & 0xFF;
+        for (int bit = 0; bit < 8; bit++)
+        {
+          text.append ((value & 0x80) != 0 ? "X" : ".");
+          value <<= 1;
+        }
+        text.append ("\n");
+      }
+      text.append ("\n");
+    }
+    return text.toString ();
+  }
+
+  public static boolean isRom (byte[] buffer)
+  {
+    if (buffer.length < 4)
+      return false;
+
+    // no idea what these mean
+    // BD 41 53 10 A0 07 08
+    return buffer[0] == (byte) 0xBD && buffer[1] == (byte) 0x41
+        && buffer[2] == (byte) 0x53 && buffer[3] == (byte) 0x10;
+  }
+
+  class Character
+  {
+    private final BufferedImage image;
+
+    public Character (byte[] buffer, int ptr)
+    {
+      // draw the image
+      image = new BufferedImage (7, 8, BufferedImage.TYPE_BYTE_GRAY);
+      DataBuffer dataBuffer = image.getRaster ().getDataBuffer ();
+      int element = 0;
+
+      for (int line = 0; line < 8; line++)
+      {
+        int value = buffer[ptr++] & 0xFF;
+        for (int bit = 0; bit < 7; bit++)
+        {
+          dataBuffer.setElem (element++, (value & 0x80) != 0 ? 255 : 0);
+          value <<= 1;
+        }
+      }
+    }
+  }
+}

src/com/bytezone/diskbrowser/applefile/Charset.java

@@ -1,5 +1,6 @@
 package com.bytezone.diskbrowser.applefile;
 
+// Found on Pascal disks
 public class Charset extends AbstractFile
 {
   public Charset (String name, byte[] buffer)

src/com/bytezone/diskbrowser/nib/MC3470.java

@@ -25,6 +25,8 @@ class MC3470
   private final byte[] dataBuffer = new byte[MAX_DATA];
   private int dataPtr;
 
+  private final byte[] rawBytes = new byte[8000];
+
   // D5 AA 96   16 sector address prologue
   // D5 AA B5   13 sector address prologue
   // D5 AA AD   data prologue
@@ -135,6 +137,54 @@ class MC3470
     return diskSectors;
   }
 
+  // ---------------------------------------------------------------------------------//
+  // getNibbleTrack
+  // ---------------------------------------------------------------------------------//
+
+  public NibbleTrack getNibbleTrack (byte[] buffer, int offset, int length, int bitsUsed)
+  {
+    int rawPtr = 0;
+
+    byte value = 0;                     // value to be stored
+    final int max = offset + length;
+    int totalBits = 0;
+    int zeroBits = 0;
+
+    while (offset < max)
+    {
+      byte b = buffer[offset++];
+      for (int mask = 0x80; mask != 0; mask >>>= 1)
+      {
+        value <<= 1;
+        if ((b & mask) != 0)
+        {
+          value |= 0x01;
+          zeroBits = 0;
+        }
+        else
+        {
+          ++zeroBits;
+          if (zeroBits > 2)
+            System.out.println (zeroBits + " consecutive zeroes");
+        }
+
+        if ((value & 0x80) != 0)     // value is not valid until the hi-bit is set
+        {
+          rawBytes[rawPtr++] = value;
+          value = 0;
+        }
+        if (++totalBits == bitsUsed)      // only use this many bits
+          break;
+      }
+    }
+
+    if (value != 0)
+      rawBytes[rawPtr++] = value;
+
+    NibbleTrack track = new NibbleTrack (rawBytes, rawPtr, bitsUsed);
+    return track;
+  }
+
   // ---------------------------------------------------------------------------------//
   // checkState
   // ---------------------------------------------------------------------------------//

src/com/bytezone/diskbrowser/nib/NibbleTrack.java

@@ -0,0 +1,14 @@
+package com.bytezone.diskbrowser.nib;
+
+public class NibbleTrack
+{
+  byte[] buffer;
+  int bitsUsed;
+
+  public NibbleTrack (byte[] buffer, int length, int bitsUsed)
+  {
+    this.bitsUsed = bitsUsed;
+    this.buffer = new byte[length];
+    System.arraycopy (buffer, 0, this.buffer, 0, length);
+  }
+}

src/com/bytezone/diskbrowser/nib/WozFile.java

@@ -4,8 +4,10 @@ import java.io.BufferedInputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.List;
 
+import com.bytezone.diskbrowser.utilities.HexFormatter;
 import com.bytezone.diskbrowser.utilities.Utility;
 
 public class WozFile
@@ -24,18 +26,20 @@ public class WozFile
   byte[] diskBuffer;
 
   private final MC3470 mc3470 = new MC3470 ();
+  private final List<NibbleTrack> nibbleTracks = new ArrayList<> (40);
 
   // ---------------------------------------------------------------------------------//
   // constructor
   // ---------------------------------------------------------------------------------//
 
-  public WozFile (File file) throws Exception
+  public WozFile (File file) throws DiskNibbleException
   {
     this.file = file;
     byte[] buffer = readFile ();
+    boolean valid = false;
 
     if (!matches (WOZ_FILE_HEADER, buffer))
-      throw new Exception ("Header error");
+      throw new DiskNibbleException ("Header error");
 
     int checksum1 = readInt (buffer, 8, 4);
     int checksum2 = Utility.crc32 (buffer, 12, buffer.length - 12);
@@ -43,7 +47,7 @@ public class WozFile
     {
       System.out.printf ("Stored checksum     : %08X%n", checksum1);
       System.out.printf ("Calculated checksum : %08X%n", checksum2);
-      throw new Exception ("Checksum error");
+      throw new DiskNibbleException ("Checksum error");
     }
 
     int ptr = 12;
@@ -110,6 +114,7 @@ public class WozFile
 
           try
           {
+            //            nibbleTracks.add (mc3470.getNibbleTrack (buffer, ptr, bytesUsed, bitCount));
             List<RawDiskSector> diskSectors =
                 mc3470.readTrack (buffer, ptr, bytesUsed, bitCount);
 
@@ -150,6 +155,28 @@ public class WozFile
         ptr += chunkSize;
       }
     }
+
+    if (!valid)
+      readNibbleTracks (buffer);
+  }
+
+  // ---------------------------------------------------------------------------------//
+  // readNibbleTracks
+  // ---------------------------------------------------------------------------------//
+
+  private void readNibbleTracks (byte[] buffer)
+  {
+    for (int track = 0; track < 35; track++)
+    {
+      int ptr = track * 6656 + 256;
+
+      int bytesUsed = readInt (buffer, ptr + DATA_SIZE, 2);
+      int bitCount = readInt (buffer, ptr + DATA_SIZE + 2, 2);
+
+      NibbleTrack nibbleTrack = mc3470.getNibbleTrack (buffer, ptr, bytesUsed, bitCount);
+      nibbleTracks.add (nibbleTrack);
+    }
+    System.out.println (HexFormatter.format (nibbleTracks.get (0).buffer));
   }
 
   // ---------------------------------------------------------------------------------//

src/com/bytezone/diskbrowser/prodos/FileEntry.java

@@ -264,6 +264,9 @@ class FileEntry extends CatalogEntry implements ProdosConstants
             file = new OriginalHiResImage (name, exactBuffer, auxType);
           else if (endOfFile == 38400 && name.startsWith ("LVL."))
             file = new LodeRunner (name, exactBuffer);
+          else if (auxType == 0x1000 && endOfFile == 0x400
+              && CharacterRom.isRom (exactBuffer))
+            file = new CharacterRom (name, exactBuffer);
           else
           {
             file = new AssemblerProgram (name, exactBuffer, auxType);