diff --git a/src/NTwain/Triplets/Control/CustomDSData.cs b/src/NTwain/Triplets/Control/CustomDSData.cs
index 33e56f5..8361ee0 100644
--- a/src/NTwain/Triplets/Control/CustomDSData.cs
+++ b/src/NTwain/Triplets/Control/CustomDSData.cs
@@ -7,60 +7,42 @@ namespace NTwain.Triplets.Control
 	{
 		internal CustomDSData(TwainSession session) : base(session) { }
 
-        public ReturnCode Get(ref TW_CUSTOMDSDATA data)
+        ReturnCode DoIt(Message msg, ref TW_CUSTOMDSDATA data)
         {
             if (Is32Bit)
             {
                 if (IsWin)
                     return NativeMethods.DsmWin32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.CustomDSData, Message.Get, ref data);
+                        DataGroups.Control, DataArgumentType.CustomDSData, msg, ref data);
                 if (IsLinux)
                     return NativeMethods.DsmLinux32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.CustomDSData, Message.Get, ref data);
+                        DataGroups.Control, DataArgumentType.CustomDSData, msg, ref data);
                 if (IsMac)
                     return NativeMethods.DsmMac32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.CustomDSData, Message.Get, ref data);
+                        DataGroups.Control, DataArgumentType.CustomDSData, msg, ref data);
             }
 
             if (IsWin)
                 return NativeMethods.DsmWin64(Session.Config.App32, Session.CurrentSource.Identity32,
-                    DataGroups.Control, DataArgumentType.CustomDSData, Message.Get, ref data);
+                    DataGroups.Control, DataArgumentType.CustomDSData, msg, ref data);
             if (IsLinux)
                 return NativeMethods.DsmLinux64(Session.Config.App32, Session.CurrentSource.Identity32,
-                    DataGroups.Control, DataArgumentType.CustomDSData, Message.Get, ref data);
+                    DataGroups.Control, DataArgumentType.CustomDSData, msg, ref data);
             if (IsMac)
                 return NativeMethods.DsmMac64(Session.Config.App32, Session.CurrentSource.Identity32,
-                    DataGroups.Control, DataArgumentType.CustomDSData, Message.Get, ref data);
-
-            return ReturnCode.Failure;
-		}
-
-		public ReturnCode Set(ref TW_CUSTOMDSDATA customData)
-        {
-            if (Is32Bit)
-            {
-                if (IsWin)
-                    return NativeMethods.DsmWin32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.CustomDSData, Message.Set, ref data);
-                if (IsLinux)
-                    return NativeMethods.DsmLinux32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.CustomDSData, Message.Set, ref data);
-                if (IsMac)
-                    return NativeMethods.DsmMac32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.CustomDSData, Message.Set, ref data);
-            }
-
-            if (IsWin)
-                return NativeMethods.DsmWin64(Session.Config.App32, Session.CurrentSource.Identity32,
-                    DataGroups.Control, DataArgumentType.CustomDSData, Message.Set, ref data);
-            if (IsLinux)
-                return NativeMethods.DsmLinux64(Session.Config.App32, Session.CurrentSource.Identity32,
-                    DataGroups.Control, DataArgumentType.CustomDSData, Message.Set, ref data);
-            if (IsMac)
-                return NativeMethods.DsmMac64(Session.Config.App32, Session.CurrentSource.Identity32,
-                    DataGroups.Control, DataArgumentType.CustomDSData, Message.Set, ref data);
+                    DataGroups.Control, DataArgumentType.CustomDSData, msg, ref data);
 
             return ReturnCode.Failure;
         }
+
+        public ReturnCode Get(ref TW_CUSTOMDSDATA data)
+        {
+            return DoIt(Message.Get, ref data);
+		}
+
+		public ReturnCode Set(ref TW_CUSTOMDSDATA data)
+        {
+            return DoIt(Message.Set, ref data);
+        }
 	}
 }
\ No newline at end of file
diff --git a/src/NTwain/Triplets/Control/FileSystem.cs b/src/NTwain/Triplets/Control/FileSystem.cs
new file mode 100644
index 0000000..a6546f6
--- /dev/null
+++ b/src/NTwain/Triplets/Control/FileSystem.cs
@@ -0,0 +1,179 @@
+using NTwain.Data;
+using NTwain.Internals;
+
+namespace NTwain.Triplets.Control
+{
+    /// <summary>
+    /// Represents <see cref="DataArgumentType.FileSystem"/>.
+    /// </summary>
+	public sealed class FileSystem : BaseTriplet
+	{
+		internal FileSystem(TwainSession session) : base(session) { }
+
+        ReturnCode DoIt(Message msg, ref TW_FILESYSTEM fileSystem)
+        {
+            if (Is32Bit)
+            {
+                if (IsWin)
+                    return NativeMethods.DsmWin32(Session.Config.App32, Session.CurrentSource.Identity32,
+                        DataGroups.Control, DataArgumentType.FileSystem, msg, ref fileSystem);
+                if (IsLinux)
+                    return NativeMethods.DsmLinux32(Session.Config.App32, Session.CurrentSource.Identity32,
+                        DataGroups.Control, DataArgumentType.FileSystem, msg, ref fileSystem);
+                if (IsMac)
+                    return NativeMethods.DsmMac32(Session.Config.App32, Session.CurrentSource.Identity32,
+                        DataGroups.Control, DataArgumentType.FileSystem, msg, ref fileSystem);
+            }
+
+            if (IsWin)
+                return NativeMethods.DsmWin64(Session.Config.App32, Session.CurrentSource.Identity32,
+                    DataGroups.Control, DataArgumentType.FileSystem, msg, ref fileSystem);
+            if (IsLinux)
+                return NativeMethods.DsmLinux64(Session.Config.App32, Session.CurrentSource.Identity32,
+                    DataGroups.Control, DataArgumentType.FileSystem, msg, ref fileSystem);
+            if (IsMac)
+                return NativeMethods.DsmMac64(Session.Config.App32, Session.CurrentSource.Identity32,
+                    DataGroups.Control, DataArgumentType.FileSystem, msg, ref fileSystem);
+
+            return ReturnCode.Failure;
+        }
+
+        /// <summary>
+        /// This operation selects the destination directory within the Source (camera, storage, etc), where
+        /// images captured using CapAutomaticCapture will be stored. This command only selects
+        /// the destination directory (a file of type Directory). The directory must exist and be
+        /// accessible to the Source. The creation of images within the directory is at the discretion of the
+        /// Source, and may result in the creation of additional sub-directories.
+        /// </summary>
+        /// <param name="fileSystem">The file system.</param>
+        /// <returns></returns>
+        public ReturnCode AutomaticCaptureDirectory(ref TW_FILESYSTEM fileSystem)
+        {
+            return DoIt(Message.AutomaticCaptureDirectory, ref fileSystem);
+		}
+
+		/// <summary>
+		/// This operation selects the current device within the Source (camera, storage, etc). If the device is
+		/// a <see cref="FileType.Domain"/>, then this command enters a directory that can contain <see cref="FileType.Host"/> files. If the
+		/// device is a <see cref="FileType.Host"/>, then this command enters a directory that can contain
+		/// <see cref="FileType.Directory"/> files. If the device is a <see cref="FileType.Directory"/>, then this command enters a
+		/// directory that can contain <see cref="FileType.Directory"/> or <see cref="FileType.Image"/> files.
+		/// </summary>
+		/// <param name="fileSystem">The file system.</param>
+		/// <returns></returns>
+		public ReturnCode ChangeDirectory(ref TW_FILESYSTEM fileSystem)
+        {
+            return DoIt(Message.ChangeDirectory, ref fileSystem);
+        }
+
+		/// <summary>
+		/// This operation copies a file or directory. Absolute and relative pathnames are supported. A file
+		/// may not be overwritten with this command. If an Application wishes to do this, it must first
+		/// delete the unwanted file and then reissue the Copy command.
+		/// The Application specifies the path and name of the entry to be copied in InputName. The
+		/// Application specifies the new patch and name in OutputName.
+		/// It is not permitted to copy files into the root directory.
+		/// </summary>
+		/// <param name="fileSystem">The file system.</param>
+		/// <returns></returns>
+		public ReturnCode Copy(ref TW_FILESYSTEM fileSystem)
+        {
+            return DoIt(Message.Copy, ref fileSystem);
+        }
+
+		/// <summary>
+		/// This operation creates a new directory within the current directory. Pathnames are not allowed,
+		/// only the name of the new directory can be specified.
+		/// </summary>
+		/// <param name="fileSystem">The file system.</param>
+		/// <returns></returns>
+		public ReturnCode CreateDirectory(ref TW_FILESYSTEM fileSystem)
+        {
+            return DoIt(Message.CreateDirectory, ref fileSystem);
+		}
+
+		/// <summary>
+		/// This operation deletes a file or directory on the device. Pathnames are not allowed, only the
+		/// name of the file or directory to be deleted can be specified. Recursive deletion can be specified
+		/// by setting the Recursive to TRUE.
+		/// </summary>
+		/// <param name="fileSystem">The file system.</param>
+		/// <returns></returns>
+		public ReturnCode Delete(ref TW_FILESYSTEM fileSystem)
+        {
+            return DoIt(Message.Delete, ref fileSystem);
+        }
+
+		/// <summary>
+		/// This operation formats the specified storage. This operation destroys all images and subdirectories
+		/// under the selected device. Use with caution.
+		/// </summary>
+		/// <param name="fileSystem">The file system.</param>
+		/// <returns></returns>
+		public ReturnCode FormatMedia(ref TW_FILESYSTEM fileSystem)
+        {
+            return DoIt(Message.FormatMedia, ref fileSystem);
+        }
+
+		/// <summary>
+		/// The operation frees the Context field in fileSystem.
+		/// Every call to GetFirstFile must be matched by
+		/// a call to GetClose to release the Context field.
+		/// </summary>
+		/// <param name="fileSystem">The file system.</param>
+		/// <returns></returns>
+		public ReturnCode GetClose(ref TW_FILESYSTEM fileSystem)
+        {
+            return DoIt(Message.GetClose, ref fileSystem);
+        }
+
+		/// <summary>
+		/// This operation gets the first filename in a directory, and returns information about that file (the
+		/// same information that can be retrieved with GetInfo).
+		/// </summary>
+		/// <param name="fileSystem">The file system.</param>
+		/// <returns></returns>
+		public ReturnCode GetFirstFile(ref TW_FILESYSTEM fileSystem)
+        {
+            return DoIt(Message.GetFirstFile, ref fileSystem);
+        }
+
+		/// <summary>
+		/// This operation fills the information fields in fileSystem.
+		/// InputName contains the absolute or relative path and filename of the requested file.
+		/// OutputName returns the absolute path to the file.
+		/// </summary>
+		/// <param name="fileSystem">The file system.</param>
+		/// <returns></returns>
+		public ReturnCode GetInfo(ref TW_FILESYSTEM fileSystem)
+        {
+            return DoIt(Message.GetInfo, ref fileSystem);
+        }
+
+		/// <summary>
+		/// This operation gets the next filename in a directory, and returns information about that file (the
+		/// same information that can be retrieved with GetInfo).
+		/// </summary>
+		/// <param name="fileSystem">The file system.</param>
+		/// <returns></returns>
+		public ReturnCode GetNextFile(ref TW_FILESYSTEM fileSystem)
+        {
+            return DoIt(Message.GetNextFile, ref fileSystem);
+        }
+
+		/// <summary>
+		/// This operation renames (and optionally moves) a file or directory. Absolute and relative path
+		/// names are supported. A file may not be overwritten with this command. If an Application
+		/// wishes to do this it must first delete the unwanted file, then issue the rename command.
+		/// The Application specifies the path and name of the entry to be renamed in InputName. The
+		/// Application specifies the new path and name in OutputName.
+		/// Filenames in the root directory cannot be moved or renamed.
+		/// </summary>
+		/// <param name="fileSystem">The file system.</param>
+		/// <returns></returns>
+		public ReturnCode Rename(ref TW_FILESYSTEM fileSystem)
+        {
+            return DoIt(Message.Rename, ref fileSystem);
+		}
+	}
+}
\ No newline at end of file
diff --git a/src/NTwain/Triplets/Control/Identity.cs b/src/NTwain/Triplets/Control/Identity.cs
index d315be0..3957f57 100644
--- a/src/NTwain/Triplets/Control/Identity.cs
+++ b/src/NTwain/Triplets/Control/Identity.cs
@@ -8,35 +8,40 @@ namespace NTwain.Triplets.Control
     {
         internal Identity(TwainSession session) : base(session) { }
 
-        public ReturnCode CloseDS(TW_IDENTITY source)
+        ReturnCode DoIt(Message msg, TW_IDENTITY source)
         {
-            var rc = ReturnCode.Failure;
-
             if (Is32Bit)
             {
                 if (IsWin)
-                    rc = NativeMethods.DsmWin32(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.CloseDS, source);
+                    return NativeMethods.DsmWin32(Session.Config.App32, IntPtr.Zero,
+                        DataGroups.Control, DataArgumentType.Identity, msg, source);
                 else if (IsLinux)
-                    rc = NativeMethods.DsmLinux32(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.CloseDS, source);
+                    return NativeMethods.DsmLinux32(Session.Config.App32, IntPtr.Zero,
+                        DataGroups.Control, DataArgumentType.Identity, msg, source);
                 else if (IsMac)
-                    rc = NativeMethods.DsmMac32(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.CloseDS, source);
+                    return NativeMethods.DsmMac32(Session.Config.App32, IntPtr.Zero,
+                        DataGroups.Control, DataArgumentType.Identity, msg, source);
             }
             else
             {
                 if (IsWin)
-                    rc = NativeMethods.DsmWin64(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.CloseDS, source);
+                    return NativeMethods.DsmWin64(Session.Config.App32, IntPtr.Zero,
+                        DataGroups.Control, DataArgumentType.Identity, msg, source);
                 else if (IsLinux)
-                    rc = NativeMethods.DsmLinux64(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.CloseDS, source);
+                    return NativeMethods.DsmLinux64(Session.Config.App32, IntPtr.Zero,
+                        DataGroups.Control, DataArgumentType.Identity, msg, source);
                 else if (IsMac)
-                    rc = NativeMethods.DsmMac64(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.CloseDS, source);
+                    return NativeMethods.DsmMac64(Session.Config.App32, IntPtr.Zero,
+                        DataGroups.Control, DataArgumentType.Identity, msg, source);
             }
 
+            return ReturnCode.Failure;
+        }
+
+        public ReturnCode CloseDS(TW_IDENTITY source)
+        {
+            var rc = DoIt(Message.CloseDS, source);
+
             if (rc == ReturnCode.Success)
             {
                 Session.State = TwainState.S3;
@@ -48,33 +53,8 @@ namespace NTwain.Triplets.Control
         public ReturnCode OpenDS(TW_IDENTITY source)
         {
             Session.StepDown(TwainState.DsmOpened);
-            var rc = ReturnCode.Failure;
-
-            if (Is32Bit)
-            {
-                if (IsWin)
-                    rc = NativeMethods.DsmWin32(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.OpenDS, source);
-                else if (IsLinux)
-                    rc = NativeMethods.DsmLinux32(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.OpenDS, source);
-                else if (IsMac)
-                    rc = NativeMethods.DsmMac32(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.OpenDS, source);
-            }
-            else
-            {
-                if (IsWin)
-                    rc = NativeMethods.DsmWin64(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.OpenDS, source);
-                else if (IsLinux)
-                    rc = NativeMethods.DsmLinux64(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.OpenDS, source);
-                else if (IsMac)
-                    rc = NativeMethods.DsmMac64(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.OpenDS, source);
-            }
-
+            var rc = DoIt(Message.OpenDS, source);
+            
             if (rc == ReturnCode.Success)
             {
                 Session.CurrentSource = Session.GetSourceSingleton(source);
@@ -87,145 +67,31 @@ namespace NTwain.Triplets.Control
         public ReturnCode GetDefault(out TW_IDENTITY source)
         {
             source = new TW_IDENTITY();
-            if (Is32Bit)
-            {
-                if (IsWin)
-                    return NativeMethods.DsmWin32(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.GetDefault, source);
-                if (IsLinux)
-                    return NativeMethods.DsmLinux32(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.GetDefault, source);
-                if (IsMac)
-                    return NativeMethods.DsmMac32(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.GetDefault, source);
-            }
-
-            if (IsWin)
-                return NativeMethods.DsmWin64(Session.Config.App32, IntPtr.Zero,
-                    DataGroups.Control, DataArgumentType.Identity, Message.GetDefault, source);
-            if (IsLinux)
-                return NativeMethods.DsmLinux64(Session.Config.App32, IntPtr.Zero,
-                    DataGroups.Control, DataArgumentType.Identity, Message.GetDefault, source);
-            if (IsMac)
-                return NativeMethods.DsmMac64(Session.Config.App32, IntPtr.Zero,
-                    DataGroups.Control, DataArgumentType.Identity, Message.GetDefault, source);
-
-            return ReturnCode.Failure;
+            return DoIt(Message.GetDefault, source);
         }
         
         public ReturnCode GetFirst(out TW_IDENTITY source)
         {
             source = new TW_IDENTITY();
-            if (Is32Bit)
-            {
-                if (IsWin)
-                    return NativeMethods.DsmWin32(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.GetFirst, source);
-                if (IsLinux)
-                    return NativeMethods.DsmLinux32(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.GetFirst, source);
-                if (IsMac)
-                    return NativeMethods.DsmMac32(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.GetFirst, source);
-            }
-
-            if (IsWin)
-                return NativeMethods.DsmWin64(Session.Config.App32, IntPtr.Zero,
-                    DataGroups.Control, DataArgumentType.Identity, Message.GetFirst, source);
-            if (IsLinux)
-                return NativeMethods.DsmLinux64(Session.Config.App32, IntPtr.Zero,
-                    DataGroups.Control, DataArgumentType.Identity, Message.GetFirst, source);
-            if (IsMac)
-                return NativeMethods.DsmMac64(Session.Config.App32, IntPtr.Zero,
-                    DataGroups.Control, DataArgumentType.Identity, Message.GetFirst, source);
-
-            return ReturnCode.Failure;
+            return DoIt(Message.GetFirst, source);
         }
 
         public ReturnCode GetNext(out TW_IDENTITY source)
         {
             source = new TW_IDENTITY();
-            if (Is32Bit)
-            {
-                if (IsWin)
-                    return NativeMethods.DsmWin32(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.GetNext, source);
-                if (IsLinux)
-                    return NativeMethods.DsmLinux32(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.GetNext, source);
-                if (IsMac)
-                    return NativeMethods.DsmMac32(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.GetNext, source);
-            }
-
-            if (IsWin)
-                return NativeMethods.DsmWin64(Session.Config.App32, IntPtr.Zero,
-                    DataGroups.Control, DataArgumentType.Identity, Message.GetNext, source);
-            if (IsLinux)
-                return NativeMethods.DsmLinux64(Session.Config.App32, IntPtr.Zero,
-                    DataGroups.Control, DataArgumentType.Identity, Message.GetNext, source);
-            if (IsMac)
-                return NativeMethods.DsmMac64(Session.Config.App32, IntPtr.Zero,
-                    DataGroups.Control, DataArgumentType.Identity, Message.GetNext, source);
-
-            return ReturnCode.Failure;
+            return DoIt(Message.GetNext, source);
         }
 
         public ReturnCode Set(DataSource source)
         {
-            if (Is32Bit)
-            {
-                if (IsWin)
-                    return NativeMethods.DsmWin32(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.Set, source?.Identity32);
-                if (IsLinux)
-                    return NativeMethods.DsmLinux32(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.Set, source?.Identity32);
-                if (IsMac)
-                    return NativeMethods.DsmMac32(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.Set, source?.Identity32);
-            }
-
-            if (IsWin)
-                return NativeMethods.DsmWin64(Session.Config.App32, IntPtr.Zero,
-                    DataGroups.Control, DataArgumentType.Identity, Message.Set, source?.Identity32);
-            if (IsLinux)
-                return NativeMethods.DsmLinux64(Session.Config.App32, IntPtr.Zero,
-                    DataGroups.Control, DataArgumentType.Identity, Message.Set, source?.Identity32);
-            if (IsMac)
-                return NativeMethods.DsmMac64(Session.Config.App32, IntPtr.Zero,
-                    DataGroups.Control, DataArgumentType.Identity, Message.Set, source?.Identity32);
-
-            return ReturnCode.Failure;
+            // TODO: platform handling
+            return DoIt(Message.Set, source?.Identity32);
         }
 
         public ReturnCode UserSelect(out TW_IDENTITY source)
         {
             source = new TW_IDENTITY();
-            if (Is32Bit)
-            {
-                if (IsWin)
-                    return NativeMethods.DsmWin32(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.UserSelect, source);
-                if (IsLinux)
-                    return NativeMethods.DsmLinux32(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.UserSelect, source);
-                if (IsMac)
-                    return NativeMethods.DsmMac32(Session.Config.App32, IntPtr.Zero,
-                        DataGroups.Control, DataArgumentType.Identity, Message.UserSelect, source);
-            }
-
-            if (IsWin)
-                return NativeMethods.DsmWin64(Session.Config.App32, IntPtr.Zero,
-                    DataGroups.Control, DataArgumentType.Identity, Message.UserSelect, source);
-            if (IsLinux)
-                return NativeMethods.DsmLinux64(Session.Config.App32, IntPtr.Zero,
-                    DataGroups.Control, DataArgumentType.Identity, Message.UserSelect, source);
-            if (IsMac)
-                return NativeMethods.DsmMac64(Session.Config.App32, IntPtr.Zero,
-                    DataGroups.Control, DataArgumentType.Identity, Message.UserSelect, source);
-
-            return ReturnCode.Failure;
+            return DoIt(Message.UserSelect, source);
         }
     }
 }
\ No newline at end of file
diff --git a/src/NTwain/Triplets/Control/PendingXfers.cs b/src/NTwain/Triplets/Control/PendingXfers.cs
index 2b5f331..1c68249 100644
--- a/src/NTwain/Triplets/Control/PendingXfers.cs
+++ b/src/NTwain/Triplets/Control/PendingXfers.cs
@@ -7,42 +7,47 @@ namespace NTwain.Triplets
 	{
 		internal PendingXfers(TwainSession session) : base(session) { }
 
-		/// <summary>
-		/// This triplet is used to cancel or terminate a transfer. Issued in state 6, this triplet cancels the next
-		/// pending transfer, discards the transfer data, and decrements the pending transfers count. In
-		/// state 7, this triplet terminates the current transfer. If any data has not been transferred (this is
-		/// only possible during a memory transfer) that data is discarded.
-		/// </summary>
-		/// <param name="pendingXfers">The pending xfers.</param>
-		/// <returns></returns>
-		internal ReturnCode EndXfer(TW_PENDINGXFERS pendingXfers)
+        ReturnCode DoIt(Message msg, ref TW_PENDINGXFERS pendingXfers)
         {
             if (Is32Bit)
             {
                 if (IsWin)
                     return NativeMethods.DsmWin32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.PendingXfers, Message.EndXfer, ref pendingXfers);
+                        DataGroups.Control, DataArgumentType.PendingXfers, msg, ref pendingXfers);
                 if (IsLinux)
                     return NativeMethods.DsmLinux32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.PendingXfers, Message.EndXfer, ref pendingXfers);
+                        DataGroups.Control, DataArgumentType.PendingXfers, msg, ref pendingXfers);
                 if (IsMac)
                     return NativeMethods.DsmMac32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.PendingXfers, Message.EndXfer, ref pendingXfers);
+                        DataGroups.Control, DataArgumentType.PendingXfers, msg, ref pendingXfers);
             }
 
             if (IsWin)
                 return NativeMethods.DsmWin64(Session.Config.App32, Session.CurrentSource.Identity32,
-                    DataGroups.Control, DataArgumentType.PendingXfers, Message.EndXfer, ref pendingXfers);
+                    DataGroups.Control, DataArgumentType.PendingXfers, msg, ref pendingXfers);
             if (IsLinux)
                 return NativeMethods.DsmLinux64(Session.Config.App32, Session.CurrentSource.Identity32,
-                    DataGroups.Control, DataArgumentType.PendingXfers, Message.EndXfer, ref pendingXfers);
+                    DataGroups.Control, DataArgumentType.PendingXfers, msg, ref pendingXfers);
             if (IsMac)
                 return NativeMethods.DsmMac64(Session.Config.App32, Session.CurrentSource.Identity32,
-                    DataGroups.Control, DataArgumentType.PendingXfers, Message.EndXfer, ref pendingXfers);
+                    DataGroups.Control, DataArgumentType.PendingXfers, msg, ref pendingXfers);
 
             return ReturnCode.Failure;
         }
 
+        /// <summary>
+        /// This triplet is used to cancel or terminate a transfer. Issued in state 6, this triplet cancels the next
+        /// pending transfer, discards the transfer data, and decrements the pending transfers count. In
+        /// state 7, this triplet terminates the current transfer. If any data has not been transferred (this is
+        /// only possible during a memory transfer) that data is discarded.
+        /// </summary>
+        /// <param name="pendingXfers">The pending xfers.</param>
+        /// <returns></returns>
+        internal ReturnCode EndXfer(ref TW_PENDINGXFERS pendingXfers)
+        {
+            return DoIt(Message.EndXfer, ref pendingXfers);
+        }
+
 		/// <summary>
 		/// Returns the number of transfers the Source is ready to supply to the application, upon demand.
 		/// If DAT_XFERGROUP is set to DG_Image, this is the number of images. If DAT_XFERGROUP is set
@@ -51,32 +56,9 @@ namespace NTwain.Triplets
 		/// </summary>
 		/// <param name="pendingXfers">The pending xfers.</param>
 		/// <returns></returns>
-		public ReturnCode Get(TW_PENDINGXFERS pendingXfers)
+		public ReturnCode Get(ref TW_PENDINGXFERS pendingXfers)
         {
-            if (Is32Bit)
-            {
-                if (IsWin)
-                    return NativeMethods.DsmWin32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.PendingXfers, Message.Get, ref pendingXfers);
-                if (IsLinux)
-                    return NativeMethods.DsmLinux32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.PendingXfers, Message.Get, ref pendingXfers);
-                if (IsMac)
-                    return NativeMethods.DsmMac32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.PendingXfers, Message.Get, ref pendingXfers);
-            }
-
-            if (IsWin)
-                return NativeMethods.DsmWin64(Session.Config.App32, Session.CurrentSource.Identity32,
-                    DataGroups.Control, DataArgumentType.PendingXfers, Message.Get, ref pendingXfers);
-            if (IsLinux)
-                return NativeMethods.DsmLinux64(Session.Config.App32, Session.CurrentSource.Identity32,
-                    DataGroups.Control, DataArgumentType.PendingXfers, Message.Get, ref pendingXfers);
-            if (IsMac)
-                return NativeMethods.DsmMac64(Session.Config.App32, Session.CurrentSource.Identity32,
-                    DataGroups.Control, DataArgumentType.PendingXfers, Message.Get, ref pendingXfers);
-
-            return ReturnCode.Failure;
+            return DoIt(Message.Get, ref pendingXfers);
         }
 
 		/// <summary>
@@ -84,32 +66,9 @@ namespace NTwain.Triplets
 		/// </summary>
 		/// <param name="pendingXfers">The pending xfers.</param>
 		/// <returns></returns>
-		internal ReturnCode Reset(TW_PENDINGXFERS pendingXfers)
+		internal ReturnCode Reset(ref TW_PENDINGXFERS pendingXfers)
         {
-            if (Is32Bit)
-            {
-                if (IsWin)
-                    return NativeMethods.DsmWin32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.PendingXfers, Message.Reset, ref pendingXfers);
-                if (IsLinux)
-                    return NativeMethods.DsmLinux32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.PendingXfers, Message.Reset, ref pendingXfers);
-                if (IsMac)
-                    return NativeMethods.DsmMac32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.PendingXfers, Message.Reset, ref pendingXfers);
-            }
-
-            if (IsWin)
-                return NativeMethods.DsmWin64(Session.Config.App32, Session.CurrentSource.Identity32,
-                    DataGroups.Control, DataArgumentType.PendingXfers, Message.Reset, ref pendingXfers);
-            if (IsLinux)
-                return NativeMethods.DsmLinux64(Session.Config.App32, Session.CurrentSource.Identity32,
-                    DataGroups.Control, DataArgumentType.PendingXfers, Message.Reset, ref pendingXfers);
-            if (IsMac)
-                return NativeMethods.DsmMac64(Session.Config.App32, Session.CurrentSource.Identity32,
-                    DataGroups.Control, DataArgumentType.PendingXfers, Message.Reset, ref pendingXfers);
-
-            return ReturnCode.Failure;
+            return DoIt(Message.Reset, ref pendingXfers);
         }
 
 		/// <summary>
@@ -118,32 +77,9 @@ namespace NTwain.Triplets
 		/// </summary>
 		/// <param name="pendingXfers">The pending xfers.</param>
 		/// <returns></returns>
-		public ReturnCode StopFeeder(TW_PENDINGXFERS pendingXfers)
+		public ReturnCode StopFeeder(ref TW_PENDINGXFERS pendingXfers)
         {
-            if (Is32Bit)
-            {
-                if (IsWin)
-                    return NativeMethods.DsmWin32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.PendingXfers, Message.StopFeeder, ref pendingXfers);
-                if (IsLinux)
-                    return NativeMethods.DsmLinux32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.PendingXfers, Message.StopFeeder, ref pendingXfers);
-                if (IsMac)
-                    return NativeMethods.DsmMac32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.PendingXfers, Message.StopFeeder, ref pendingXfers);
-            }
-
-            if (IsWin)
-                return NativeMethods.DsmWin64(Session.Config.App32, Session.CurrentSource.Identity32,
-                    DataGroups.Control, DataArgumentType.PendingXfers, Message.StopFeeder, ref pendingXfers);
-            if (IsLinux)
-                return NativeMethods.DsmLinux64(Session.Config.App32, Session.CurrentSource.Identity32,
-                    DataGroups.Control, DataArgumentType.PendingXfers, Message.StopFeeder, ref pendingXfers);
-            if (IsMac)
-                return NativeMethods.DsmMac64(Session.Config.App32, Session.CurrentSource.Identity32,
-                    DataGroups.Control, DataArgumentType.PendingXfers, Message.StopFeeder, ref pendingXfers);
-
-            return ReturnCode.Failure;
+            return DoIt(Message.StopFeeder, ref pendingXfers);
         }
 	}
 }
\ No newline at end of file
diff --git a/src/NTwain/Triplets/Control/UserInterface.cs b/src/NTwain/Triplets/Control/UserInterface.cs
index 428fdf0..a61347f 100644
--- a/src/NTwain/Triplets/Control/UserInterface.cs
+++ b/src/NTwain/Triplets/Control/UserInterface.cs
@@ -10,35 +10,40 @@ namespace NTwain.Triplets.Control
     {
         internal UserInterface(TwainSession session) : base(session) { }
 
-        public ReturnCode DisableDS(ref TW_USERINTERFACE ui, bool wasUIonly)
+        ReturnCode DoIt(Message msg, ref TW_USERINTERFACE ui)
         {
-            var rc = ReturnCode.Failure;
-
             if (Is32Bit)
             {
                 if (IsWin)
-                    rc = NativeMethods.DsmWin32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.UserInterface, Message.DisableDS, ref ui);
+                    return NativeMethods.DsmWin32(Session.Config.App32, Session.CurrentSource.Identity32,
+                        DataGroups.Control, DataArgumentType.UserInterface, msg, ref ui);
                 else if (IsLinux)
-                    rc = NativeMethods.DsmLinux32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.UserInterface, Message.DisableDS, ref ui);
+                    return NativeMethods.DsmLinux32(Session.Config.App32, Session.CurrentSource.Identity32,
+                        DataGroups.Control, DataArgumentType.UserInterface, msg, ref ui);
                 else if (IsMac)
-                    rc = NativeMethods.DsmMac32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.UserInterface, Message.DisableDS, ref ui);
+                    return NativeMethods.DsmMac32(Session.Config.App32, Session.CurrentSource.Identity32,
+                        DataGroups.Control, DataArgumentType.UserInterface, msg, ref ui);
             }
             else
             {
                 if (IsWin)
-                    rc = NativeMethods.DsmWin64(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.UserInterface, Message.DisableDS, ref ui);
+                    return NativeMethods.DsmWin64(Session.Config.App32, Session.CurrentSource.Identity32,
+                        DataGroups.Control, DataArgumentType.UserInterface, msg, ref ui);
                 else if (IsLinux)
-                    rc = NativeMethods.DsmLinux64(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.UserInterface, Message.DisableDS, ref ui);
+                    return NativeMethods.DsmLinux64(Session.Config.App32, Session.CurrentSource.Identity32,
+                        DataGroups.Control, DataArgumentType.UserInterface, msg, ref ui);
                 else if (IsMac)
-                    rc = NativeMethods.DsmMac64(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.UserInterface, Message.DisableDS, ref ui);
+                    return NativeMethods.DsmMac64(Session.Config.App32, Session.CurrentSource.Identity32,
+                        DataGroups.Control, DataArgumentType.UserInterface, msg, ref ui);
             }
 
+            return ReturnCode.Failure;
+        }
+
+        public ReturnCode DisableDS(ref TW_USERINTERFACE ui, bool wasUIonly)
+        {
+            var rc = DoIt(Message.DisableDS, ref ui);
+
             if (rc == ReturnCode.Success)
             {
                 Session.State = TwainState.S4;
@@ -58,30 +63,7 @@ namespace NTwain.Triplets.Control
             {
                 Session.State = TwainState.S5; //tentative
 
-                if (Is32Bit)
-                {
-                    if (IsWin)
-                        rc = NativeMethods.DsmWin32(Session.Config.App32, Session.CurrentSource.Identity32,
-                            DataGroups.Control, DataArgumentType.UserInterface, Message.EnableDS, ref ui);
-                    else if (IsLinux)
-                        rc = NativeMethods.DsmLinux32(Session.Config.App32, Session.CurrentSource.Identity32,
-                            DataGroups.Control, DataArgumentType.UserInterface, Message.EnableDS, ref ui);
-                    else if (IsMac)
-                        rc = NativeMethods.DsmMac32(Session.Config.App32, Session.CurrentSource.Identity32,
-                            DataGroups.Control, DataArgumentType.UserInterface, Message.EnableDS, ref ui);
-                }
-                else
-                {
-                    if (IsWin)
-                        rc = NativeMethods.DsmWin64(Session.Config.App32, Session.CurrentSource.Identity32,
-                            DataGroups.Control, DataArgumentType.UserInterface, Message.EnableDS, ref ui);
-                    else if (IsLinux)
-                        rc = NativeMethods.DsmLinux64(Session.Config.App32, Session.CurrentSource.Identity32,
-                            DataGroups.Control, DataArgumentType.UserInterface, Message.EnableDS, ref ui);
-                    else if (IsMac)
-                        rc = NativeMethods.DsmMac64(Session.Config.App32, Session.CurrentSource.Identity32,
-                            DataGroups.Control, DataArgumentType.UserInterface, Message.DisableDS, ref ui);
-                }
+                rc = DoIt(Message.EnableDS, ref ui);
 
                 if (!(rc == ReturnCode.Success &&
                     (ui.ShowUI == 0 && rc == ReturnCode.CheckStatus)))
@@ -99,30 +81,7 @@ namespace NTwain.Triplets.Control
             {
                 Session.State = TwainState.S5; //tentative
 
-                if (Is32Bit)
-                {
-                    if (IsWin)
-                        rc = NativeMethods.DsmWin32(Session.Config.App32, Session.CurrentSource.Identity32,
-                            DataGroups.Control, DataArgumentType.UserInterface, Message.EnableDSUIOnly, ref ui);
-                    else if (IsLinux)
-                        rc = NativeMethods.DsmLinux32(Session.Config.App32, Session.CurrentSource.Identity32,
-                            DataGroups.Control, DataArgumentType.UserInterface, Message.EnableDSUIOnly, ref ui);
-                    else if (IsMac)
-                        rc = NativeMethods.DsmMac32(Session.Config.App32, Session.CurrentSource.Identity32,
-                            DataGroups.Control, DataArgumentType.UserInterface, Message.EnableDSUIOnly, ref ui);
-                }
-                else
-                {
-                    if (IsWin)
-                        rc = NativeMethods.DsmWin64(Session.Config.App32, Session.CurrentSource.Identity32,
-                            DataGroups.Control, DataArgumentType.UserInterface, Message.EnableDSUIOnly, ref ui);
-                    else if (IsLinux)
-                        rc = NativeMethods.DsmLinux64(Session.Config.App32, Session.CurrentSource.Identity32,
-                            DataGroups.Control, DataArgumentType.UserInterface, Message.EnableDSUIOnly, ref ui);
-                    else if (IsMac)
-                        rc = NativeMethods.DsmMac64(Session.Config.App32, Session.CurrentSource.Identity32,
-                            DataGroups.Control, DataArgumentType.UserInterface, Message.EnableDSUIOnly, ref ui);
-                }
+                rc = DoIt(Message.EnableDSUIOnly, ref ui);
 
                 if (rc != ReturnCode.Success)
                 {
diff --git a/src/NTwain/Triplets/Control/XferGroup.cs b/src/NTwain/Triplets/Control/XferGroup.cs
index da1480f..9188ea3 100644
--- a/src/NTwain/Triplets/Control/XferGroup.cs
+++ b/src/NTwain/Triplets/Control/XferGroup.cs
@@ -10,38 +10,43 @@ namespace NTwain.Triplets.Control
 	{
 		internal XferGroup(TwainSession session) : base(session) { }
 
-		/// <summary>
-		/// Returns the Data Group (the type of data) for the upcoming transfer. The Source is required to
-		/// only supply one of the DGs specified in the SupportedGroups field of origin.
-		/// </summary>
-		/// <param name="value">The value.</param>
-		/// <returns></returns>
-        public ReturnCode Get(ref DataGroups value)
+        ReturnCode DoIt(Message msg, ref DataGroups value)
         {
             if (Is32Bit)
             {
                 if (IsWin)
                     return NativeMethods.DsmWin32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.XferGroup, Message.Get, ref value);
+                        DataGroups.Control, DataArgumentType.XferGroup, msg, ref value);
                 if (IsLinux)
                     return NativeMethods.DsmLinux32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.XferGroup, Message.Get, ref value);
+                        DataGroups.Control, DataArgumentType.XferGroup, msg, ref value);
                 if (IsMac)
                     return NativeMethods.DsmMac32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.XferGroup, Message.Get, ref value);
+                        DataGroups.Control, DataArgumentType.XferGroup, msg, ref value);
             }
 
             if (IsWin)
                 return NativeMethods.DsmWin64(Session.Config.App32, Session.CurrentSource.Identity32,
-                    DataGroups.Control, DataArgumentType.XferGroup, Message.Get, ref value);
+                    DataGroups.Control, DataArgumentType.XferGroup, msg, ref value);
             if (IsLinux)
                 return NativeMethods.DsmLinux64(Session.Config.App32, Session.CurrentSource.Identity32,
-                    DataGroups.Control, DataArgumentType.XferGroup, Message.Get, ref value);
+                    DataGroups.Control, DataArgumentType.XferGroup, msg, ref value);
             if (IsMac)
                 return NativeMethods.DsmMac64(Session.Config.App32, Session.CurrentSource.Identity32,
-                    DataGroups.Control, DataArgumentType.XferGroup, Message.Get, ref value);
+                    DataGroups.Control, DataArgumentType.XferGroup, msg, ref value);
 
             return ReturnCode.Failure;
+        }
+
+        /// <summary>
+        /// Returns the Data Group (the type of data) for the upcoming transfer. The Source is required to
+        /// only supply one of the DGs specified in the SupportedGroups field of origin.
+        /// </summary>
+        /// <param name="value">The value.</param>
+        /// <returns></returns>
+        public ReturnCode Get(ref DataGroups value)
+        {
+            return DoIt(Message.Get, ref value);
 		}
 
         /// <summary>
@@ -53,30 +58,7 @@ namespace NTwain.Triplets.Control
         /// <returns></returns>
         public ReturnCode Set(DataGroups value)
         {
-            if (Is32Bit)
-            {
-                if (IsWin)
-                    return NativeMethods.DsmWin32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.XferGroup, Message.Set, ref value);
-                if (IsLinux)
-                    return NativeMethods.DsmLinux32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.XferGroup, Message.Set, ref value);
-                if (IsMac)
-                    return NativeMethods.DsmMac32(Session.Config.App32, Session.CurrentSource.Identity32,
-                        DataGroups.Control, DataArgumentType.XferGroup, Message.Set, ref value);
-            }
-
-            if (IsWin)
-                return NativeMethods.DsmWin64(Session.Config.App32, Session.CurrentSource.Identity32,
-                    DataGroups.Control, DataArgumentType.XferGroup, Message.Set, ref value);
-            if (IsLinux)
-                return NativeMethods.DsmLinux64(Session.Config.App32, Session.CurrentSource.Identity32,
-                    DataGroups.Control, DataArgumentType.XferGroup, Message.Set, ref value);
-            if (IsMac)
-                return NativeMethods.DsmMac64(Session.Config.App32, Session.CurrentSource.Identity32,
-                    DataGroups.Control, DataArgumentType.XferGroup, Message.Set, ref value);
-
-            return ReturnCode.Failure;
+            return DoIt(Message.Set, ref value);
         }
 	}
 }
\ No newline at end of file
diff --git a/src/NTwain/Triplets/DGControl.cs b/src/NTwain/Triplets/DGControl.cs
index 42da90d..4c38499 100644
--- a/src/NTwain/Triplets/DGControl.cs
+++ b/src/NTwain/Triplets/DGControl.cs
@@ -63,6 +63,12 @@ namespace NTwain.Triplets
         /// </summary>
         public SetupMemXfer SetupMemXfer => _memXfer ?? (_memXfer = new SetupMemXfer(Session));
 
+        FileSystem _fs;
+        /// <summary>
+        /// Gets the operations defined for DAT_FILESYSTEM.
+        /// </summary>
+        public FileSystem FileSystem  => _fs ?? (_fs = new FileSystem(Session));
+
         XferGroup _xferGroup;
         /// <summary>
         /// Gets the operations defined for DAT_XFERGROUP.