diff --git a/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/DiskConstants.java b/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/DiskConstants.java
index 756e327c..a75bf686 100644
--- a/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/DiskConstants.java
+++ b/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/DiskConstants.java
@@ -32,7 +32,8 @@ public interface DiskConstants {
     int PRODOS_BLOCKS_ON_800KB_DISK = 1600;
     int DOS32_SECTORS_ON_115KB_DISK = 455;
 	int DOS33_SECTORS_ON_140KB_DISK = 560;
-	int APPLE_140KB_DISK = 143360;
+	int APPLE_140KB_DISK = 143360;  // standard 35 track x 16 sector disk
+    int APPLE_160KB_DISK = 163840;  // largest(?) 5.25" disk of 40 tracks x 16 sectors
     int APPLE_13SECTOR_DISK = 116480;
 	int APPLE_140KB_NIBBLE_DISK = 232960;
     int APPLE_400KB_DISK = 409600;
diff --git a/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/DiskFactory.java b/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/DiskFactory.java
index a6d9c73a..3435da6d 100644
--- a/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/DiskFactory.java
+++ b/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/DiskFactory.java
@@ -101,7 +101,7 @@ public interface DiskFactory {
                         devices.add(new TrackSectorToBlockAdapter(converted, TrackSectorToBlockAdapter.BlockStyle.PRODOS));
                     }
                 }
-                else if (ctx.source.isApproxEQ(DiskConstants.APPLE_140KB_DISK)) {
+                else if (ctx.source.isApproxBetween(DiskConstants.APPLE_140KB_DISK, DiskConstants.APPLE_160KB_DISK)) {
                     if (ctx.source.is(Hint.DOS_SECTOR_ORDER) || ctx.source.extensionLike("do")) {
                         TrackSectorDevice doDevice = new DosOrderedTrackSectorDevice(ctx.source, Hint.DOS_SECTOR_ORDER);
                         TrackSectorDevice poDevice = SkewedTrackSectorDevice.dosToPascalSkew(doDevice);
@@ -126,7 +126,8 @@ public interface DiskFactory {
                 return this;
             }
             public BlockDeviceBuilder includeHDV() {
-                if (ctx.source.getSize() > DiskConstants.APPLE_800KB_DISK) {
+                // Anything not a floppy is included -- but if we have a device, assume it was picked up elsewhere...
+                if (ctx.source.getSize() > DiskConstants.APPLE_140KB_NIBBLE_DISK && devices.isEmpty()) {
                     devices.add(new ProdosOrderedBlockDevice(ctx.source, BlockDevice.STANDARD_BLOCK_SIZE));
                 }
                 return this;
@@ -160,47 +161,40 @@ public interface DiskFactory {
                 return this;
             }
             public TrackSectorDeviceBuilder include16Sector(Hint hint) {
+                assert hint == Hint.DOS_SECTOR_ORDER || hint == Hint.NIBBLE_SECTOR_ORDER;
                 if (ctx.nibbleTrackReaderWriter != null) {
                     Optional<TrackSectorDevice> nibble = TrackSectorNibbleDevice.identify(ctx.nibbleTrackReaderWriter);
                     nibble.ifPresent(device -> {
                         if (device.getGeometry().sectorsPerTrack() == 16) {
                             TrackSectorDevice converted = switch (hint) {
                                 case DOS_SECTOR_ORDER -> SkewedTrackSectorDevice.physicalToDosSkew(nibble.get());
-                                case PRODOS_BLOCK_ORDER -> SkewedTrackSectorDevice.physicalToPascalSkew(nibble.get());
                                 case NIBBLE_SECTOR_ORDER -> nibble.get();
                                 default -> throw new RuntimeException("wrong hint type: " + hint);
                             };
                             devices.add(converted);
                         }
                     });
-                } else if (ctx.source.isApproxEQ(DiskConstants.APPLE_140KB_DISK)) {
+                }
+                else if (ctx.source.isApproxBetween(DiskConstants.APPLE_140KB_DISK, DiskConstants.APPLE_160KB_DISK)) {
                     TrackSectorDevice doDevice = null;
                     TrackSectorDevice poDevice = null;
                     if (ctx.source.is(Hint.DOS_SECTOR_ORDER) || ctx.source.extensionLike("do")) {
                         doDevice = new DosOrderedTrackSectorDevice(ctx.source, Hint.DOS_SECTOR_ORDER);
                     }
                     else if (ctx.source.is(Hint.PRODOS_BLOCK_ORDER) || ctx.source.extensionLike("po")) {
-                        poDevice = new DosOrderedTrackSectorDevice(ctx.source, Hint.PRODOS_BLOCK_ORDER);
+                        BlockDevice blockDevice = new ProdosOrderedBlockDevice(ctx.source, BlockDevice.STANDARD_BLOCK_SIZE);
+                        poDevice = new BlockToTrackSectorAdapter(blockDevice, new ProdosBlockToTrackSectorAdapterStrategy());
                     }
                     else {
                         doDevice = new DosOrderedTrackSectorDevice(ctx.source, Hint.DOS_SECTOR_ORDER);
-                        poDevice = new DosOrderedTrackSectorDevice(ctx.source, Hint.PRODOS_BLOCK_ORDER);
+                        BlockDevice blockDevice = new ProdosOrderedBlockDevice(ctx.source, BlockDevice.STANDARD_BLOCK_SIZE);
+                        poDevice = new BlockToTrackSectorAdapter(blockDevice, new ProdosBlockToTrackSectorAdapterStrategy());
                     }
                     switch (hint) {
                         case DOS_SECTOR_ORDER -> {
                             if (doDevice != null) {
                                 devices.add(doDevice);
                             }
-                            if (poDevice != null) {
-                                TrackSectorDevice tmp = SkewedTrackSectorDevice.pascalToPhysicalSkew(poDevice);
-                                devices.add(SkewedTrackSectorDevice.physicalToDosSkew(tmp));
-                            }
-                        }
-                        case PRODOS_BLOCK_ORDER -> {
-                            if (doDevice != null) {
-                                TrackSectorDevice tmp = SkewedTrackSectorDevice.dosToPhysicalSkew(doDevice);
-                                devices.add(SkewedTrackSectorDevice.physicalToPascalSkew(tmp));
-                            }
                             if (poDevice != null) {
                                 devices.add(poDevice);
                             }
@@ -210,7 +204,7 @@ public interface DiskFactory {
                                 devices.add(SkewedTrackSectorDevice.dosToPhysicalSkew(doDevice));
                             }
                             if (poDevice != null) {
-                                devices.add(SkewedTrackSectorDevice.pascalToPhysicalSkew(poDevice));
+                                devices.add(SkewedTrackSectorDevice.dosToPhysicalSkew(poDevice));
                             }
                         }
                     }