diff --git a/src/com/webcodepro/applecommander/storage/DosFormatDisk.java b/src/com/webcodepro/applecommander/storage/DosFormatDisk.java
index 12d6656..e986072 100644
--- a/src/com/webcodepro/applecommander/storage/DosFormatDisk.java
+++ b/src/com/webcodepro/applecommander/storage/DosFormatDisk.java
@@ -474,4 +474,11 @@ public class DosFormatDisk extends FormattedDisk {
 				+ ") combination.");
 		}
 	}
+
+	/**
+	 * Returns the logical disk number.  Returns a 0 to indicate no numbering.
+	 */
+	public int getLogicalDiskNumber() {
+		return 0;
+	}
 }
diff --git a/src/com/webcodepro/applecommander/storage/FormattedDisk.java b/src/com/webcodepro/applecommander/storage/FormattedDisk.java
index 039034e..b337edc 100644
--- a/src/com/webcodepro/applecommander/storage/FormattedDisk.java
+++ b/src/com/webcodepro/applecommander/storage/FormattedDisk.java
@@ -322,4 +322,12 @@ public abstract class FormattedDisk extends Disk {
 			}
 		}
 	}
+	
+	/**
+	 * Returns the logical disk number.  This can be used to identify
+	 * between disks when a format supports multiple logical volumes.
+	 * If a value of 0 is returned, there is not multiple logical
+	 * volumes to distinguish.
+	 */
+	public abstract int getLogicalDiskNumber();
 }
diff --git a/src/com/webcodepro/applecommander/storage/PascalFormatDisk.java b/src/com/webcodepro/applecommander/storage/PascalFormatDisk.java
index 88235af..432f2e5 100644
--- a/src/com/webcodepro/applecommander/storage/PascalFormatDisk.java
+++ b/src/com/webcodepro/applecommander/storage/PascalFormatDisk.java
@@ -417,4 +417,10 @@ public class PascalFormatDisk extends FormattedDisk {
 		writeDirectory(directory);
 	}
 
+	/**
+	 * Returns the logical disk number.  Returns a 0 to indicate no numbering.
+	 */
+	public int getLogicalDiskNumber() {
+		return 0;
+	}
 }
diff --git a/src/com/webcodepro/applecommander/storage/ProdosFormatDisk.java b/src/com/webcodepro/applecommander/storage/ProdosFormatDisk.java
index 81af7c6..a448020 100644
--- a/src/com/webcodepro/applecommander/storage/ProdosFormatDisk.java
+++ b/src/com/webcodepro/applecommander/storage/ProdosFormatDisk.java
@@ -487,4 +487,10 @@ public class ProdosFormatDisk extends FormattedDisk {
 		writeVolumeBitMap(bitmap);
 	}
 
+	/**
+	 * Returns the logical disk number.  Returns a 0 to indicate no numbering.
+	 */
+	public int getLogicalDiskNumber() {
+		return 0;
+	}
 }
diff --git a/src/com/webcodepro/applecommander/storage/RdosFormatDisk.java b/src/com/webcodepro/applecommander/storage/RdosFormatDisk.java
index 65fea17..bda81da 100644
--- a/src/com/webcodepro/applecommander/storage/RdosFormatDisk.java
+++ b/src/com/webcodepro/applecommander/storage/RdosFormatDisk.java
@@ -391,4 +391,10 @@ public class RdosFormatDisk extends FormattedDisk {
 		writeRdosBlock(13, data);
 	}
 
+	/**
+	 * Returns the logical disk number.  Returns a 0 to indicate no numbering.
+	 */
+	public int getLogicalDiskNumber() {
+		return 0;
+	}
 }
diff --git a/src/com/webcodepro/applecommander/storage/UniDosFormatDisk.java b/src/com/webcodepro/applecommander/storage/UniDosFormatDisk.java
new file mode 100644
index 0000000..746681e
--- /dev/null
+++ b/src/com/webcodepro/applecommander/storage/UniDosFormatDisk.java
@@ -0,0 +1,99 @@
+/*
+ * AppleCommander - An Apple ][ image utility.
+ * Copyright (C) 2002 by Robert Greene
+ * robgreene at users.sourceforge.net
+ *
+ * This program is free software; you can redistribute it and/or modify it 
+ * under the terms of the GNU General Public License as published by the 
+ * Free Software Foundation; either version 2 of the License, or (at your 
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but 
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along 
+ * with this program; if not, write to the Free Software Foundation, Inc., 
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+package com.webcodepro.applecommander.storage;
+
+/**
+ * Manages a disk that is in UniDOS format.
+ * This is basically DOS 3.3 except that the disk has two volumes of
+ * each 400K.
+ * <br>
+ * Created on Dec 13, 2002.
+ * @author Rob
+ */
+public class UniDosFormatDisk extends DosFormatDisk {
+	/**
+	 * Use this indicator to work with logical disk #1.
+	 * It is essentially the offset into the disk image.
+	 */
+	public static final int UNIDOS_DISK_1 = 0;
+	/**
+	 * Use this indicator to work with logical disk #2.
+	 * It is essentially the offset into the disk image.
+	 */
+	public static final int UNIDOS_DISK_2 = 409600;
+	/**
+	 * Indicates which logical disk to work with (by offset
+	 * into the disk image itself).
+	 */
+	private int logicalOffset;
+	/**
+	 * Constructor for UniDosFormatDisk.
+	 * @param filename
+	 * @param diskImage
+	 */
+	public UniDosFormatDisk(String filename, byte[] diskImage, int logicalOffset) {
+		super(filename, diskImage);
+		this.logicalOffset = logicalOffset;
+	}
+	/**
+	 * Constructor for UniDosFormatDisk.
+	 * @param filename
+	 */
+	public UniDosFormatDisk(String filename, int logicalOffset) {
+		super(filename);
+		this.logicalOffset = logicalOffset;
+	}
+	/**
+	 * Answer with the name of this disk.
+	 * @see com.webcodepro.applecommander.storage.FormattedDisk#getDiskName()
+	 */
+	public String getDiskName() {
+		if (logicalOffset == UNIDOS_DISK_1) {
+			return super.getDiskName() + " (Disk 1)";
+		} else if (logicalOffset == UNIDOS_DISK_2) {
+			return super.getDiskName() + " (Disk 2)";
+		} else {
+			return super.getDiskName();
+		}
+	}
+
+	/**
+	 * Modify the disk offset by the logical disk offset.  This allows
+	 * simple support for two DOS volumes on a UniDOS disk.
+	 * @see com.webcodepro.applecommander.storage.Disk#getOffset(int, int)
+	 */
+	protected int getOffset(int track, int sector) throws IllegalArgumentException {
+		return super.getOffset(track, sector) + logicalOffset;
+	}
+
+	/**
+	 * Returns the logical disk number.  This can be used to identify
+	 * between disks when a format supports multiple logical volumes.
+	 */
+	public int getLogicalDiskNumber() {
+		if (logicalOffset == UNIDOS_DISK_1) {
+			return 1;
+		} else if (logicalOffset == UNIDOS_DISK_2) {
+			return 2;
+		} else {
+			return 0;
+		}
+	}
+}