diff --git a/app/cli-acx/src/main/java/io/github/applecommander/acx/command/DumpCommand.java b/app/cli-acx/src/main/java/io/github/applecommander/acx/command/DumpCommand.java
index 0f8c9e74..ad43ad8c 100644
--- a/app/cli-acx/src/main/java/io/github/applecommander/acx/command/DumpCommand.java
+++ b/app/cli-acx/src/main/java/io/github/applecommander/acx/command/DumpCommand.java
@@ -20,7 +20,6 @@
 package io.github.applecommander.acx.command;
 
 import com.webcodepro.applecommander.util.AppleUtil;
-import com.webcodepro.applecommander.util.Range;
 import io.github.applecommander.acx.base.ReadOnlyDiskContextCommandOptions;
 import io.github.applecommander.acx.converter.IntegerTypeConverter;
 import io.github.applecommander.acx.converter.RangeTypeConverter;
@@ -38,6 +37,7 @@ import org.applecommander.hint.Hint;
 import org.applecommander.util.Container;
 import org.applecommander.util.DataBuffer;
 import org.applecommander.util.InformationGroup;
+import org.applecommander.util.Range;
 import picocli.CommandLine.ArgGroup;
 import picocli.CommandLine.Command;
 import picocli.CommandLine.Mixin;
@@ -379,7 +379,7 @@ public class DumpCommand extends ReadOnlyDiskContextCommandOptions {
         private Range sectors;
 
         public boolean isBootSector() {
-            return tracks.getFirst() == 0 && tracks.getLast() == 0 && sectors.getFirst() == 0 && sectors.getLast() == 0;
+            return tracks.first() == 0 && tracks.last() == 0 && sectors.first() == 0 && sectors.last() == 0;
         }
     }
     public static class NibbleTrackRangeSelection {
diff --git a/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/os/dos33/DosDiskCheck.java b/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/os/dos33/DosDiskCheck.java
index c0523e0a..413f792c 100644
--- a/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/os/dos33/DosDiskCheck.java
+++ b/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/os/dos33/DosDiskCheck.java
@@ -22,8 +22,8 @@ package com.webcodepro.applecommander.storage.os.dos33;
 import com.webcodepro.applecommander.storage.DiskConstants;
 import com.webcodepro.applecommander.storage.FileEntry;
 import com.webcodepro.applecommander.util.AppleUtil;
+import org.applecommander.device.Coordinate;
 import org.applecommander.device.TrackSectorDevice;
-import org.applecommander.os.Coordinate;
 import org.applecommander.os.DiskCheck;
 import org.applecommander.util.DataBuffer;
 
diff --git a/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/os/dos33/DosFileEntry.java b/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/os/dos33/DosFileEntry.java
index a5b4be4a..7f8cbe1f 100644
--- a/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/os/dos33/DosFileEntry.java
+++ b/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/os/dos33/DosFileEntry.java
@@ -23,7 +23,7 @@ import com.webcodepro.applecommander.storage.*;
 import com.webcodepro.applecommander.storage.filters.*;
 import com.webcodepro.applecommander.util.AppleUtil;
 import com.webcodepro.applecommander.util.TextBundle;
-import org.applecommander.os.Coordinate;
+import org.applecommander.device.Coordinate;
 
 import java.text.NumberFormat;
 import java.util.ArrayList;
diff --git a/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/os/dos33/DosFormatDisk.java b/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/os/dos33/DosFormatDisk.java
index e4f374ea..bf42d2ef 100644
--- a/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/os/dos33/DosFormatDisk.java
+++ b/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/os/dos33/DosFormatDisk.java
@@ -22,11 +22,7 @@ package com.webcodepro.applecommander.storage.os.dos33;
 import com.webcodepro.applecommander.storage.*;
 import com.webcodepro.applecommander.util.AppleUtil;
 import com.webcodepro.applecommander.util.TextBundle;
-import org.applecommander.device.BlockDevice;
-import org.applecommander.device.BlockToTrackSectorAdapter;
-import org.applecommander.device.TrackSectorDevice;
-import org.applecommander.device.TrackSectorToBlockStrategy;
-import org.applecommander.os.Coordinate;
+import org.applecommander.device.*;
 import org.applecommander.source.Source;
 import org.applecommander.util.Container;
 import org.applecommander.util.DataBuffer;
diff --git a/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/os/prodos/ProdosDiskCheck.java b/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/os/prodos/ProdosDiskCheck.java
index e05b7fd1..160145d0 100644
--- a/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/os/prodos/ProdosDiskCheck.java
+++ b/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/os/prodos/ProdosDiskCheck.java
@@ -22,7 +22,7 @@ package com.webcodepro.applecommander.storage.os.prodos;
 import com.webcodepro.applecommander.storage.DirectoryEntry;
 import com.webcodepro.applecommander.storage.DiskException;
 import org.applecommander.device.BlockDevice;
-import org.applecommander.os.Coordinate;
+import org.applecommander.device.Coordinate;
 import org.applecommander.os.DiskCheck;
 import org.applecommander.util.DataBuffer;
 
diff --git a/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/os/prodos/ProdosFormatDisk.java b/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/os/prodos/ProdosFormatDisk.java
index ac1c5183..dfe5447b 100644
--- a/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/os/prodos/ProdosFormatDisk.java
+++ b/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/os/prodos/ProdosFormatDisk.java
@@ -23,7 +23,7 @@ import com.webcodepro.applecommander.storage.*;
 import com.webcodepro.applecommander.util.AppleUtil;
 import com.webcodepro.applecommander.util.TextBundle;
 import org.applecommander.device.BlockDevice;
-import org.applecommander.os.Coordinate;
+import org.applecommander.device.Coordinate;
 import org.applecommander.source.Source;
 import org.applecommander.util.Container;
 import org.applecommander.util.DataBuffer;
diff --git a/lib/ac-api/src/main/java/org/applecommander/os/Coordinate.java b/lib/ac-api/src/main/java/org/applecommander/device/Coordinate.java
similarity index 98%
rename from lib/ac-api/src/main/java/org/applecommander/os/Coordinate.java
rename to lib/ac-api/src/main/java/org/applecommander/device/Coordinate.java
index d7d05c78..06180e89 100644
--- a/lib/ac-api/src/main/java/org/applecommander/os/Coordinate.java
+++ b/lib/ac-api/src/main/java/org/applecommander/device/Coordinate.java
@@ -17,7 +17,7 @@
  * with this program; if not, write to the Free Software Foundation, Inc.,
  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */
-package org.applecommander.os;
+package org.applecommander.device;
 
 /// A simplistic set of Coordinates. Note that block only matches to block while track and sector have
 /// two forms that match against each other.
diff --git a/lib/ac-api/src/main/java/org/applecommander/device/TrackSectorNibbleDiskCheck.java b/lib/ac-api/src/main/java/org/applecommander/device/TrackSectorNibbleDiskCheck.java
index 6007d84a..7128ee02 100644
--- a/lib/ac-api/src/main/java/org/applecommander/device/TrackSectorNibbleDiskCheck.java
+++ b/lib/ac-api/src/main/java/org/applecommander/device/TrackSectorNibbleDiskCheck.java
@@ -21,7 +21,6 @@ package org.applecommander.device;
 
 import com.webcodepro.applecommander.util.Range;
 import org.applecommander.capability.Capability;
-import org.applecommander.os.Coordinate;
 import org.applecommander.os.DiskCheck;
 import org.applecommander.util.DataBuffer;
 
diff --git a/lib/ac-api/src/main/java/org/applecommander/exception/DirectoryFullException.java b/lib/ac-api/src/main/java/org/applecommander/exception/DirectoryFullException.java
new file mode 100644
index 00000000..d70371c1
--- /dev/null
+++ b/lib/ac-api/src/main/java/org/applecommander/exception/DirectoryFullException.java
@@ -0,0 +1,18 @@
+package org.applecommander.exception;
+
+public class DirectoryFullException extends RuntimeException {
+    public DirectoryFullException() {
+    }
+
+    public DirectoryFullException(String fmt, Object ...args) {
+        super(String.format(fmt, args));
+    }
+
+    public DirectoryFullException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public DirectoryFullException(Throwable cause) {
+        super(cause);
+    }
+}
diff --git a/lib/ac-api/src/main/java/org/applecommander/os/DiskCheck.java b/lib/ac-api/src/main/java/org/applecommander/os/DiskCheck.java
index f7e52bd0..ebd4e736 100644
--- a/lib/ac-api/src/main/java/org/applecommander/os/DiskCheck.java
+++ b/lib/ac-api/src/main/java/org/applecommander/os/DiskCheck.java
@@ -19,6 +19,8 @@
  */
 package org.applecommander.os;
 
+import org.applecommander.device.Coordinate;
+
 import java.util.List;
 import java.util.Optional;
 
diff --git a/lib/ac-api/src/test/java/org/applecommander/os/CoordinateTest.java b/lib/ac-api/src/test/java/org/applecommander/device/CoordinateTest.java
similarity index 98%
rename from lib/ac-api/src/test/java/org/applecommander/os/CoordinateTest.java
rename to lib/ac-api/src/test/java/org/applecommander/device/CoordinateTest.java
index 36ab5da9..3776eefb 100644
--- a/lib/ac-api/src/test/java/org/applecommander/os/CoordinateTest.java
+++ b/lib/ac-api/src/test/java/org/applecommander/device/CoordinateTest.java
@@ -17,7 +17,7 @@
  * with this program; if not, write to the Free Software Foundation, Inc.,
  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */
-package org.applecommander.os;
+package org.applecommander.device;
 
 import org.junit.jupiter.api.Test;