diff --git a/src/com/bytezone/diskbrowser/cpm/CPMDisk.java b/src/com/bytezone/diskbrowser/cpm/CPMDisk.java
index bc04646..b59269a 100644
--- a/src/com/bytezone/diskbrowser/cpm/CPMDisk.java
+++ b/src/com/bytezone/diskbrowser/cpm/CPMDisk.java
@@ -161,19 +161,17 @@ public class CPMDisk extends AbstractFormattedDisk
   {
     disk.setInterleave (3);
 
-    byte[] buffer = disk.readSector (0, 8);
-    String text = new String (buffer, 16, 24);
-    if ("DIR ERA TYPESAVEREN USER".equals (text))
-      return true;
-
-    buffer = disk.readSector (0, 4);
-    text = new String (buffer, 16, 24);
-    if ("DIR ERA TYPESAVEREN USER".equals (text))
-      return true;
+    for (int i = 8; i >= 4; i -= 2)
+    {
+      byte[] buffer = disk.readSector (0, i);
+      String text = new String (buffer, 16, 24);
+      if ("DIR ERA TYPESAVEREN USER".equals (text))
+        return true;
+    }
 
     for (int sector = 0; sector < 8; sector++)
     {
-      buffer = disk.readSector (3, sector);
+      byte[] buffer = disk.readSector (3, sector);
       for (int i = 0; i < buffer.length; i += 32)
       {
         int val = buffer[i] & 0xFF;
diff --git a/src/com/bytezone/diskbrowser/disk/DiskFactory.java b/src/com/bytezone/diskbrowser/disk/DiskFactory.java
index 8006c26..cddffd8 100755
--- a/src/com/bytezone/diskbrowser/disk/DiskFactory.java
+++ b/src/com/bytezone/diskbrowser/disk/DiskFactory.java
@@ -16,6 +16,7 @@ import com.bytezone.diskbrowser.pascal.PascalDisk;
 import com.bytezone.diskbrowser.prodos.ProdosDisk;
 import com.bytezone.diskbrowser.utilities.FileFormatException;
 import com.bytezone.diskbrowser.utilities.NuFX;
+import com.bytezone.diskbrowser.utilities.Utility;
 import com.bytezone.diskbrowser.wizardry.Wizardry4BootDisk;
 import com.bytezone.diskbrowser.wizardry.WizardryScenarioDisk;
 
@@ -43,13 +44,41 @@ public class DiskFactory
 
     String suffix = path.substring (path.lastIndexOf (".") + 1).toLowerCase ();
     Boolean compressed = false;
-    Path p = Paths.get (path);
+    Path originalPath = Paths.get (path);
+
+    if (suffix.equals ("gz"))
+    {
+      try
+      {
+        InputStream in = new GZIPInputStream (new FileInputStream (path));
+        File tmp = File.createTempFile ("gzip", null);
+        FileOutputStream fos = new FileOutputStream (tmp);
+
+        int bytesRead;
+        byte[] buffer = new byte[1024];
+        while ((bytesRead = in.read (buffer)) > 0)
+          fos.write (buffer, 0, bytesRead);
+
+        fos.close ();
+        in.close ();
+        tmp.deleteOnExit ();
+
+        suffix = Utility.getSuffix (file.getName ());     // ignores the .gz
+        file = tmp;
+        compressed = true;
+      }
+      catch (IOException e)  // can get EOFException: Unexpected end of ZLIB input stream
+      {
+        e.printStackTrace ();
+        return null;
+      }
+    }
 
     if (suffix.equals ("sdk"))
     {
       try
       {
-        NuFX nuFX = new NuFX (p);
+        NuFX nuFX = new NuFX (file);
         File tmp = File.createTempFile ("sdk", null);
         FileOutputStream fos = new FileOutputStream (tmp);
         fos.write (nuFX.getBuffer ());
@@ -69,32 +98,6 @@ public class DiskFactory
         return null;
       }
     }
-    else if (suffix.equals ("gz"))    // will be .dsk.gz
-    {
-      try
-      {
-        InputStream in = new GZIPInputStream (new FileInputStream (path));
-        File tmp = File.createTempFile ("gzip", null);
-        FileOutputStream fos = new FileOutputStream (tmp);
-
-        int bytesRead;
-        byte[] buffer = new byte[1024];
-        while ((bytesRead = in.read (buffer)) > 0)
-          fos.write (buffer, 0, bytesRead);
-
-        fos.close ();
-        in.close ();
-        tmp.deleteOnExit ();
-        file = tmp;
-        suffix = "dsk";
-        compressed = true;
-      }
-      catch (IOException e)  // can get EOFException: Unexpected end of ZLIB input stream
-      {
-        e.printStackTrace ();
-        return null;
-      }
-    }
 
     FormattedDisk disk = null;
     FormattedDisk disk2 = null;
@@ -132,7 +135,7 @@ public class DiskFactory
       if (disk != null)
       {
         if (compressed)
-          disk.setOriginalPath (p);
+          disk.setOriginalPath (originalPath);
         return disk;
       }
 
@@ -231,7 +234,7 @@ public class DiskFactory
       if (disk != null)
       {
         if (compressed)
-          disk.setOriginalPath (p);
+          disk.setOriginalPath (originalPath);
         return disk;
       }
 
@@ -283,7 +286,7 @@ public class DiskFactory
           "Factory creating disk : " + disk.getDisk ().getFile ().getAbsolutePath ());
 
     if (disk != null && compressed)
-      disk.setOriginalPath (p);
+      disk.setOriginalPath (originalPath);
 
     return disk;
   }
diff --git a/src/com/bytezone/diskbrowser/duplicates/DiskTableModel.java b/src/com/bytezone/diskbrowser/duplicates/DiskTableModel.java
index dc6cfc6..b19c4b7 100644
--- a/src/com/bytezone/diskbrowser/duplicates/DiskTableModel.java
+++ b/src/com/bytezone/diskbrowser/duplicates/DiskTableModel.java
@@ -2,7 +2,6 @@ package com.bytezone.diskbrowser.duplicates;
 
 import java.util.ArrayList;
 import java.util.List;
-import java.util.Map;
 
 import javax.swing.table.AbstractTableModel;
 
@@ -11,27 +10,34 @@ import com.bytezone.diskbrowser.utilities.Utility;
 public class DiskTableModel extends AbstractTableModel
 {
   static final String[] headers =
-      { "Path", "Name", "Type", "Size", "Dup name", "Dup data", "Checksum" };
+      { "Path", "Name", "Type", "Size", "# names", "Checksum", "# checksums" };
 
-  Map<String, DiskDetails> fileNameMap;
-  Map<Long, DiskDetails> checkSumMap;
-  List<TableLine> lines = new ArrayList<DiskTableModel.TableLine> ();
+  //  Map<String, DiskDetails> fileNameMap;
+  //  Map<Long, DiskDetails> checkSumMap;
+  private final List<TableLine> lines = new ArrayList<DiskTableModel.TableLine> ();
+  private final RootFolderData rootFolderData;
 
   public DiskTableModel (RootFolderData rootFolderData)
   {
-    fileNameMap = rootFolderData.fileNameMap;
-    checkSumMap = rootFolderData.checksumMap;
+    //    fileNameMap = rootFolderData.fileNameMap;
+    //    checkSumMap = rootFolderData.checksumMap;
+    this.rootFolderData = rootFolderData;
 
-    for (String key : fileNameMap.keySet ())
+    for (String key : rootFolderData.fileNameMap.keySet ())
     {
-      DiskDetails original = fileNameMap.get (key);
-      lines.add (new TableLine (original));
+      DiskDetails original = rootFolderData.fileNameMap.get (key);
+      lines.add (new TableLine (original, rootFolderData));
 
       for (DiskDetails duplicate : original.getDuplicateNames ())
-        lines.add (new TableLine (duplicate));
+        lines.add (new TableLine (duplicate, rootFolderData));
     }
   }
 
+  public DiskDetails getDiskDetails (int rowIndex)
+  {
+    return lines.get (rowIndex).diskDetails;
+  }
+
   @Override
   public String getColumnName (int column)
   {
@@ -47,7 +53,10 @@ public class DiskTableModel extends AbstractTableModel
   @Override
   public int getColumnCount ()
   {
-    return headers.length;
+    if (rootFolderData.doChecksums)
+      return headers.length;
+    else
+      return headers.length - 1;
   }
 
   @Override
@@ -73,9 +82,9 @@ public class DiskTableModel extends AbstractTableModel
       case 4:
         return line.duplicateNames;
       case 5:
-        return line.duplicateChecksums;
-      case 6:
         return line.checksum;
+      case 6:
+        return line.duplicateChecksums;
       default:
         return "???";
     }
@@ -93,7 +102,7 @@ public class DiskTableModel extends AbstractTableModel
   {
     TableLine line = lines.get (rowIndex);
     line.checksum = line.diskDetails.calculateChecksum ();
-    fireTableCellUpdated (rowIndex, 6);
+    fireTableCellUpdated (rowIndex, 5);
   }
 
   class TableLine
@@ -107,7 +116,7 @@ public class DiskTableModel extends AbstractTableModel
     private final String type;
     private final long size;
 
-    public TableLine (DiskDetails diskDetails)
+    public TableLine (DiskDetails diskDetails, RootFolderData rootFolderData)
     {
       this.diskDetails = diskDetails;
       shortName = diskDetails.getShortName ();
@@ -118,17 +127,22 @@ public class DiskTableModel extends AbstractTableModel
       String rootName = diskDetails.getRootName ();
       path = rootName.substring (0, rootName.length () - shortName.length ());
 
-      if (diskDetails.isDuplicateChecksum ())
-      {
-        DiskDetails original = checkSumMap.get (diskDetails.getChecksum ());
-        duplicateChecksums = original.getDuplicateChecksums ().size () + 1;
-      }
+      if (rootFolderData.doChecksums)
+        if (diskDetails.isDuplicateChecksum ())
+        {
+          DiskDetails original =
+              rootFolderData.checksumMap.get (diskDetails.getChecksum ());
+          duplicateChecksums = original.getDuplicateChecksums ().size () + 1;
+        }
+        else
+          duplicateChecksums = diskDetails.getDuplicateChecksums ().size () + 1;
       else
-        duplicateChecksums = diskDetails.getDuplicateChecksums ().size () + 1;
+        duplicateChecksums = 0;
 
       if (diskDetails.isDuplicateName ())
       {
-        DiskDetails original = fileNameMap.get (diskDetails.getShortName ());
+        DiskDetails original =
+            rootFolderData.fileNameMap.get (diskDetails.getShortName ());
         duplicateNames = original.getDuplicateNames ().size () + 1;
       }
       else
diff --git a/src/com/bytezone/diskbrowser/duplicates/DisksWindow.java b/src/com/bytezone/diskbrowser/duplicates/DisksWindow.java
index 46e62b7..b146368 100644
--- a/src/com/bytezone/diskbrowser/duplicates/DisksWindow.java
+++ b/src/com/bytezone/diskbrowser/duplicates/DisksWindow.java
@@ -29,10 +29,12 @@ public class DisksWindow extends JFrame
   private final JButton btnHide = new JButton ("Close");
   private final JButton btnTotals = new JButton ("Totals");
   private final JPanel topPanel = new JPanel ();
+
   private final List<JCheckBox> boxes = new ArrayList<JCheckBox> ();
   private TableRowSorter<DiskTableModel> sorter;
   private final CheckBoxActionListener checkBoxActionListener =
       new CheckBoxActionListener ();
+
   private DiskTableModel diskTableModel;
   private final RootFolderData rootFolderData;
 
@@ -40,6 +42,7 @@ public class DisksWindow extends JFrame
   {
     super ("Disk List - " + rootFolderData.getRootFolder ().getAbsolutePath ());
     this.rootFolderData = rootFolderData;
+    //    rootFolderData.progressPanel.cancelled = false;
 
     table = new JTable ();
     JScrollPane scrollPane =
@@ -102,11 +105,15 @@ public class DisksWindow extends JFrame
     diskTableModel = new DiskTableModel (rootFolderData);
     table.setModel (diskTableModel);
 
-    int[] columnWidths = { 300, 300, 30, 40, 40, 40, 100 };
+    int[] columnWidths = { 300, 300, 30, 40, 40, 100 };
     TableColumnModel tcm = table.getColumnModel ();
     for (int i = 0; i < columnWidths.length; i++)
       tcm.getColumn (i).setPreferredWidth (columnWidths[i]);
 
+    // extra column if doing checksums
+    if (rootFolderData.doChecksums)
+      tcm.getColumn (6).setPreferredWidth (40);
+
     tcm.getColumn (3).setCellRenderer (NumberRenderer.getIntegerRenderer ());
 
     sorter = new TableRowSorter<DiskTableModel> ((DiskTableModel) table.getModel ());
@@ -131,7 +138,7 @@ public class DisksWindow extends JFrame
         int actualRow = sorter.convertRowIndexToModel (selectedRow);
 
         DiskTableModel diskTableModel = (DiskTableModel) table.getModel ();
-        DiskDetails diskDetails = diskTableModel.lines.get (actualRow).diskDetails;
+        DiskDetails diskDetails = diskTableModel.getDiskDetails (actualRow);
 
         long checksum = diskDetails.getChecksum ();
         if (checksum == 0)
@@ -166,8 +173,7 @@ public class DisksWindow extends JFrame
     setLocationRelativeTo (null);
     btnExport.setEnabled (true);
 
-    if (!rootFolderData.showTotals)
-      setVisible (true);
+    setVisible (true);
   }
 
   private String getFilterText ()
diff --git a/src/com/bytezone/diskbrowser/duplicates/DuplicateSwingWorker.java b/src/com/bytezone/diskbrowser/duplicates/DuplicateSwingWorker.java
index 2b094ec..17811a2 100644
--- a/src/com/bytezone/diskbrowser/duplicates/DuplicateSwingWorker.java
+++ b/src/com/bytezone/diskbrowser/duplicates/DuplicateSwingWorker.java
@@ -14,31 +14,19 @@ public class DuplicateSwingWorker extends SwingWorker<Void, RootFolderData>
   public DuplicateSwingWorker (RootFolderData rootFolderData)
   {
     this.rootFolderData = rootFolderData;
-    rootFolderData.dialogTotals.setVisible (true);
   }
 
   @Override
   protected Void doInBackground () throws Exception
   {
     traverse (rootFolderData.getRootFolder ());
-    publish (rootFolderData);
-    rootFolderData.print ();
     return null;
   }
 
   @Override
   protected void done ()
   {
-    try
-    {
-      if (!rootFolderData.showTotals)
-        rootFolderData.dialogTotals.setVisible (false);
-      rootFolderData.windowDisks.setTableData (rootFolderData);
-    }
-    catch (Exception e)
-    {
-      e.printStackTrace ();
-    }
+    rootFolderData.done ();
   }
 
   @Override
@@ -49,6 +37,9 @@ public class DuplicateSwingWorker extends SwingWorker<Void, RootFolderData>
 
   private void traverse (File directory)
   {
+    if (rootFolderData.progressPanel.cancelled)
+      return;
+
     File[] files = directory.listFiles ();
 
     if (files == null || files.length == 0)
@@ -59,6 +50,9 @@ public class DuplicateSwingWorker extends SwingWorker<Void, RootFolderData>
 
     for (File file : files)
     {
+      if (rootFolderData.progressPanel.cancelled)
+        return;
+
       if (file.isDirectory ())
       {
         rootFolderData.incrementFolders ();
@@ -70,7 +64,7 @@ public class DuplicateSwingWorker extends SwingWorker<Void, RootFolderData>
         if (Utility.validFileType (fileName) && file.length () > 0)
         {
           rootFolderData.incrementType (file, fileName);
-          if ((rootFolderData.totalDisks % 500) == 0)
+          if ((rootFolderData.totalDisks % 250) == 0)
             publish (rootFolderData);
         }
       }
diff --git a/src/com/bytezone/diskbrowser/duplicates/RootFolderData.java b/src/com/bytezone/diskbrowser/duplicates/RootFolderData.java
index 97cee90..4ece558 100644
--- a/src/com/bytezone/diskbrowser/duplicates/RootFolderData.java
+++ b/src/com/bytezone/diskbrowser/duplicates/RootFolderData.java
@@ -1,10 +1,8 @@
 package com.bytezone.diskbrowser.duplicates;
 
-import java.awt.Color;
-import java.awt.Dimension;
-import java.awt.Font;
-import java.awt.Graphics;
-import java.awt.Graphics2D;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
 import java.io.File;
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -12,6 +10,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.TreeMap;
 
+import javax.swing.JButton;
 import javax.swing.JDialog;
 import javax.swing.JPanel;
 
@@ -31,15 +30,12 @@ public class RootFolderData
   final Map<Long, DiskDetails> checksumMap = new HashMap<Long, DiskDetails> ();
   final Map<String, DiskDetails> fileNameMap = new TreeMap<String, DiskDetails> ();
 
-  final ProgressPanel progressPanel;
-  public JDialog dialogTotals;
-  public DisksWindow windowDisks;
+  public DisksWindow disksWindow;
 
   public final List<DiskTableSelectionListener> listeners =
       new ArrayList<DiskTableSelectionListener> ();
 
   public boolean doChecksums;
-  public boolean showTotals;
 
   int totalDisks;
   int totalFolders;
@@ -47,29 +43,109 @@ public class RootFolderData
   // total files for each suffix (uncompressed, .gz, .zip, total)
   int[][] typeTotals;
 
-  public RootFolderData ()
+  // Progress dialog
+  ProgressPanel progressPanel;
+  public JDialog dialogTotals;
+  JPanel southPanel;
+  JButton btnCancel;
+  JButton btnOK;
+
+  //  public RootFolderData ()
+  //  {
+  //  }
+
+  private void createWindows ()
   {
+    southPanel = new JPanel ();
+    btnCancel = new JButton ("Cancel");
+    btnOK = new JButton ("OK");
+
     progressPanel = new ProgressPanel ();
     progressPanel.setPreferredSize (new Dimension (560, 300));
 
-    dialogTotals = new JDialog (windowDisks);
-    dialogTotals.add (progressPanel);
+    dialogTotals = new JDialog (disksWindow);
+    dialogTotals.add (progressPanel, BorderLayout.CENTER);
+    southPanel.add (btnCancel);
+    dialogTotals.add (southPanel, BorderLayout.SOUTH);
     dialogTotals.setTitle ("Disk Totals");
     dialogTotals.pack ();
     dialogTotals.setLocationRelativeTo (null);
+    //    btnCancel.requestFocus ();
+
+    btnCancel.addActionListener (new ActionListener ()
+    {
+      @Override
+      public void actionPerformed (ActionEvent e)
+      {
+        progressPanel.cancelled = true;
+        dialogTotals.setVisible (false);
+      }
+    });
+
+    btnOK.addActionListener (new ActionListener ()
+    {
+      @Override
+      public void actionPerformed (ActionEvent e)
+      {
+        dialogTotals.setVisible (false);
+      }
+    });
+  }
+
+  public void count (boolean doChecksums)
+  {
+    if (dialogTotals == null)
+      createWindows ();
+    clear ();
+
+    setButton (btnCancel);
+
+    this.doChecksums = doChecksums;
+    progressPanel.cancelled = false;
+    disksWindow = new DisksWindow (this);
+    dialogTotals.setVisible (true);
+    new DuplicateSwingWorker (this).execute ();           // start SwingWorker
+  }
+
+  public void done ()                                     // SwingWorker has completed
+  {
+    print ();
+    dialogTotals.repaint ();
+    dialogTotals.setVisible (false);
+
+    if (progressPanel.cancelled)
+      disksWindow = null;
+    else
+    {
+      disksWindow.setTableData (this);
+      setButton (btnOK);
+    }
+  }
+
+  private void setButton (JButton button)
+  {
+    southPanel.removeAll ();
+    southPanel.add (button);
+    dialogTotals.revalidate ();
+    dialogTotals.repaint ();
   }
 
   public void setRootFolder (File rootFolder)
   {
     this.rootFolder = rootFolder;
+    rootFolderNameLength = rootFolder.getAbsolutePath ().length ();
+    disksWindow = null;           // force a recount
+    //    clear ();
+  }
+
+  private void clear ()
+  {
     typeTotals = new int[4][Utility.suffixes.size ()];
     totalDisks = 0;
     totalFolders = 0;
-    windowDisks = null;
 
     checksumMap.clear ();
     fileNameMap.clear ();
-    rootFolderNameLength = rootFolder.getAbsolutePath ().length ();
   }
 
   public File getRootFolder ()
@@ -82,11 +158,6 @@ public class RootFolderData
     ++totalFolders;
   }
 
-  public int getTotalType (int type)
-  {
-    return typeTotals[0][type] + typeTotals[1][type] + typeTotals[2][type];
-  }
-
   public void incrementType (File file, String filename)
   {
     int pos = Utility.getSuffixNo (filename);
@@ -127,6 +198,11 @@ public class RootFolderData
     }
   }
 
+  public int getTotalType (int type)
+  {
+    return typeTotals[0][type] + typeTotals[1][type] + typeTotals[2][type];
+  }
+
   public void print ()
   {
     System.out.printf ("%nFolders ...... %,7d%n", totalFolders);
@@ -151,10 +227,13 @@ public class RootFolderData
     System.out.printf ("Total           %,7d  %,7d  %,7d  %,7d%n%n", grandTotal[0],
         grandTotal[1], grandTotal[2], grandTotal[3]);
     System.out.printf ("Unique checksums: %,d%n", checksumMap.size ());
+    System.out.printf ("Duplicate disks : %,d%n", totalDisks - checksumMap.size ());
   }
 
   class ProgressPanel extends JPanel
   {
+    public volatile boolean cancelled;
+
     @Override
     protected void paintComponent (Graphics graphics)
     {
diff --git a/src/com/bytezone/diskbrowser/gui/DuplicateAction.java b/src/com/bytezone/diskbrowser/gui/DuplicateAction.java
index a486ad4..19a6276 100644
--- a/src/com/bytezone/diskbrowser/gui/DuplicateAction.java
+++ b/src/com/bytezone/diskbrowser/gui/DuplicateAction.java
@@ -10,8 +10,6 @@ import javax.swing.KeyStroke;
 
 import com.bytezone.common.DefaultAction;
 import com.bytezone.diskbrowser.duplicates.DiskDetails;
-import com.bytezone.diskbrowser.duplicates.DuplicateSwingWorker;
-import com.bytezone.diskbrowser.duplicates.DisksWindow;
 import com.bytezone.diskbrowser.duplicates.RootFolderData;
 import com.bytezone.diskbrowser.gui.RootDirectoryAction.RootDirectoryChangeListener;
 
@@ -43,7 +41,7 @@ public class DuplicateAction extends DefaultAction implements RootDirectoryChang
   @Override
   public void actionPerformed (ActionEvent arg0)
   {
-    if (rootFolderData.windowDisks == null)
+    if (rootFolderData.disksWindow == null)
     {
       Object[] options = { "Generate checksums", "Disk names only", "Cancel" };
       int option = JOptionPane.showOptionDialog (null,
@@ -54,14 +52,10 @@ public class DuplicateAction extends DefaultAction implements RootDirectoryChang
           "Generate Disk Listing", JOptionPane.YES_NO_CANCEL_OPTION,
           JOptionPane.QUESTION_MESSAGE, null, options, options[1]);   // just disk names
       if (option < 2)
-      {
-        rootFolderData.doChecksums = option == 0;
-        rootFolderData.windowDisks = new DisksWindow (rootFolderData);
-        new DuplicateSwingWorker (rootFolderData).execute ();
-      }
+        rootFolderData.count (option == 0);
     }
     else
-      rootFolderData.windowDisks.setVisible (true);
+      rootFolderData.disksWindow.setVisible (true);
   }
 
   public void addTableSelectionListener (DiskTableSelectionListener listener)
diff --git a/src/com/bytezone/diskbrowser/utilities/NuFX.java b/src/com/bytezone/diskbrowser/utilities/NuFX.java
index 982d2f1..a300a77 100644
--- a/src/com/bytezone/diskbrowser/utilities/NuFX.java
+++ b/src/com/bytezone/diskbrowser/utilities/NuFX.java
@@ -1,5 +1,6 @@
 package com.bytezone.diskbrowser.utilities;
 
+import java.io.File;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -10,11 +11,12 @@ import com.bytezone.common.Utility;
 
 public class NuFX
 {
-  private static String[] fileSystems = {//
-        "", "ProDOS/SOS", "DOS 3.3", "DOS 3.2", "Apple II Pascal", "Macintosh HFS",
-            "Macintosh MFS", "Lisa File System", "Apple CP/M", "", "MS-DOS", "High Sierra",
-            "ISO 9660", "AppleShare" };
-  private final Header header;
+  private static String[] fileSystems =
+      {//
+       "", "ProDOS/SOS", "DOS 3.3", "DOS 3.2", "Apple II Pascal", "Macintosh HFS",
+       "Macintosh MFS", "Lisa File System", "Apple CP/M", "", "MS-DOS", "High Sierra",
+       "ISO 9660", "AppleShare" };
+  private Header header;
   private final byte[] buffer;
   private final boolean debug = false;
 
@@ -24,6 +26,17 @@ public class NuFX
   public NuFX (Path path) throws FileFormatException, IOException
   {
     buffer = Files.readAllBytes (path);
+    readBuffer ();
+  }
+
+  public NuFX (File file) throws FileFormatException, IOException
+  {
+    buffer = Files.readAllBytes (file.toPath ());
+    readBuffer ();
+  }
+
+  private void readBuffer ()
+  {
     header = new Header (buffer);
 
     int dataPtr = 48;
@@ -138,8 +151,8 @@ public class NuFX
     private boolean isNuFile (byte[] buffer, int ptr)
     {
       if (buffer[ptr] == 0x4E && buffer[ptr + 1] == (byte) 0xF5 && buffer[ptr + 2] == 0x46
-            && buffer[ptr + 3] == (byte) 0xE9 && buffer[ptr + 4] == 0x6C
-            && buffer[ptr + 5] == (byte) 0xE5)
+          && buffer[ptr + 3] == (byte) 0xE9 && buffer[ptr + 4] == 0x6C
+          && buffer[ptr + 5] == (byte) 0xE5)
         return true;
       return false;
     }
@@ -147,7 +160,7 @@ public class NuFX
     private boolean isBin2 (byte[] buffer, int ptr)
     {
       if (buffer[ptr] == 0x0A && buffer[ptr + 1] == 0x47 && buffer[ptr + 2] == 0x4C
-            && buffer[ptr + 18] == (byte) 0x02)
+          && buffer[ptr + 18] == (byte) 0x02)
         return true;
       return false;
     }
@@ -234,7 +247,7 @@ public class NuFX
     private boolean isNuFX (byte[] buffer, int ptr)
     {
       if (buffer[ptr] == 0x4E && buffer[ptr + 1] == (byte) 0xF5 && buffer[ptr + 2] == 0x46
-            && buffer[ptr + 3] == (byte) 0xD8)
+          && buffer[ptr + 3] == (byte) 0xD8)
         return true;
       return false;
     }
@@ -249,7 +262,7 @@ public class NuFX
       text.append (String.format ("Version ........ %d%n", version));
       text.append (String.format ("Threads ........ %d%n", totThreads));
       text.append (String.format ("File sys id .... %d (%s)%n", fileSystemID,
-                                  fileSystems[fileSystemID]));
+          fileSystems[fileSystemID]));
       text.append (String.format ("Separator ...... %s%n", separator));
       text.append (String.format ("Access ......... %,d%n", access));
       text.append (String.format ("File type ...... %,d%n", fileType));
diff --git a/src/com/bytezone/diskbrowser/utilities/Utility.java b/src/com/bytezone/diskbrowser/utilities/Utility.java
index 97d657c..b8e91a2 100644
--- a/src/com/bytezone/diskbrowser/utilities/Utility.java
+++ b/src/com/bytezone/diskbrowser/utilities/Utility.java
@@ -80,26 +80,6 @@ public class Utility
 
   public static boolean validFileType (String filename)
   {
-    //    String lcFilename = filename.toLowerCase ();
-    //    if (lcFilename.endsWith (".gz"))
-    //      lcFilename = lcFilename.substring (0, lcFilename.length () - 3);
-    //    else if (lcFilename.endsWith (".zip"))
-    //      lcFilename = lcFilename.substring (0, lcFilename.length () - 4);
-    //
-    //    int dotPos = lcFilename.lastIndexOf ('.');
-    //    if (dotPos < 0)
-    //      return false;
-    //
-    //    String suffix = lcFilename.substring (dotPos + 1);
-
-    //    int dotPos2 = filename.lastIndexOf ('.', dotPos - 1);
-    //    if (dotPos2 > 0)
-    //    {
-    //      String suffix2 = filename.substring (dotPos2 + 1, dotPos).toLowerCase ();
-    //      if (suffix.equals ("gz"))
-    //        return suffixes.contains (suffix2) && !"gz".equals (suffix2);
-    //    }
-
     return suffixes.contains (getSuffix (filename));
   }
 }
\ No newline at end of file