diff --git a/SabreTools.DatFiles/Formats/Missfile.Reader.cs b/SabreTools.DatFiles/Formats/Missfile.Reader.cs
new file mode 100644
index 00000000..fa12a0bf
--- /dev/null
+++ b/SabreTools.DatFiles/Formats/Missfile.Reader.cs
@@ -0,0 +1,17 @@
+using System;
+
+namespace SabreTools.DatFiles.Formats
+{
+    /// <summary>
+    /// Represents parsing a Missfile
+    /// </summary>
+    internal partial class Missfile : DatFile
+    {
+        /// <inheritdoc/>
+        /// <remarks>There is no consistent way to parse a missfile</remarks>
+        public override void ParseFile(string filename, int indexId, bool keep, bool statsOnly = false, bool throwOnError = false)
+        {
+            throw new NotImplementedException();
+        }
+    }
+}
diff --git a/SabreTools.DatFiles/Formats/Missfile.Writer.cs b/SabreTools.DatFiles/Formats/Missfile.Writer.cs
new file mode 100644
index 00000000..da2cde2a
--- /dev/null
+++ b/SabreTools.DatFiles/Formats/Missfile.Writer.cs
@@ -0,0 +1,103 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Text;
+using SabreTools.Core;
+using SabreTools.DatItems;
+
+namespace SabreTools.DatFiles.Formats
+{
+    /// <summary>
+    /// Represents writing a Missfile
+    /// </summary>
+    internal partial class Missfile : DatFile
+    {
+        /// <inheritdoc/>
+        protected override List<DatItemField> GetMissingRequiredFields(DatItem datItem)
+        {
+            // TODO: Check required fields
+            return null;
+        }
+
+        /// <inheritdoc/>
+        public override bool WriteToFile(string outfile, bool ignoreblanks = false, bool throwOnError = false)
+        {
+            try
+            {
+                logger.User($"Writing to '{outfile}'...");
+                FileStream fs = File.Create(outfile);
+
+                // If we get back null for some reason, just log and return
+                if (fs == null)
+                {
+                    logger.Warning($"File '{outfile}' could not be created for writing! Please check to see if the file is writable");
+                    return false;
+                }
+
+                StreamWriter sw = new(fs, new UTF8Encoding(false));
+
+                // Write out each of the machines and roms
+                string lastgame = null;
+
+                // Use a sorted list of games to output
+                foreach (string key in Items.SortedKeys)
+                {
+                    ConcurrentList<DatItem> datItems = Items.FilteredItems(key);
+
+                    // If this machine doesn't contain any writable items, skip
+                    if (!ContainsWritable(datItems))
+                        continue;
+
+                    // Resolve the names in the block
+                    datItems = DatItem.ResolveNames(datItems);
+
+                    for (int index = 0; index < datItems.Count; index++)
+                    {
+                        DatItem datItem = datItems[index];
+
+                        // Check for a "null" item
+                        datItem = ProcessNullifiedItem(datItem);
+
+                        // Write out the item if we're using machine names or we're not ignoring
+                        if (!Header.UseRomName || !ShouldIgnore(datItem, ignoreblanks))
+                            WriteDatItem(sw, datItem, lastgame);
+
+                        // Set the new data to compare against
+                        lastgame = datItem.Machine.Name;
+                    }
+                }
+
+                logger.User($"'{outfile}' written!{Environment.NewLine}");
+                sw.Dispose();
+                fs.Dispose();
+            }
+            catch (Exception ex) when (!throwOnError)
+            {
+                logger.Error(ex);
+                return false;
+            }
+
+            return true;
+        }
+
+        /// <summary>
+        /// Write out DatItem using the supplied StreamWriter
+        /// </summary>
+        /// <param name="sw">StreamWriter to output to</param>
+        /// <param name="datItem">DatItem object to be output</param>
+        /// <param name="lastgame">The name of the last game to be output</param>
+        private void WriteDatItem(StreamWriter sw, DatItem datItem, string lastgame)
+        {
+            // Process the item name
+            ProcessItemName(datItem, false, forceRomName: false);
+
+            // Romba mode automatically uses item name
+            if (Header.OutputDepot?.IsActive == true || Header.UseRomName)
+                sw.Write($"{datItem.GetName() ?? string.Empty}\n");
+            else if (!Header.UseRomName && datItem.Machine.Name != lastgame)
+                sw.Write($"{datItem.Machine.Name}\n");
+
+            sw.Flush();
+        }
+    }
+}
diff --git a/SabreTools.DatFiles/Formats/Missfile.cs b/SabreTools.DatFiles/Formats/Missfile.cs
index c33a4acb..1c38332c 100644
--- a/SabreTools.DatFiles/Formats/Missfile.cs
+++ b/SabreTools.DatFiles/Formats/Missfile.cs
@@ -1,16 +1,9 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Text;
-using SabreTools.Core;
-using SabreTools.DatItems;
-
-namespace SabreTools.DatFiles.Formats
+namespace SabreTools.DatFiles.Formats
 {
     /// <summary>
-    /// Represents parsing and writing of a Missfile
+    /// Represents a Missfile
     /// </summary>
-    internal class Missfile : DatFile
+    internal partial class Missfile : DatFile
     {
         /// <summary>
         /// Constructor designed for casting a base DatFile
@@ -20,100 +13,5 @@ namespace SabreTools.DatFiles.Formats
             : base(datFile)
         {
         }
-
-        /// <inheritdoc/>
-        public override void ParseFile(string filename, int indexId, bool keep, bool statsOnly = false, bool throwOnError = false)
-        {
-            // There is no consistent way to parse a missfile...
-            throw new NotImplementedException();
-        }
-
-        /// <inheritdoc/>
-        protected override List<DatItemField> GetMissingRequiredFields(DatItem datItem)
-        {
-            // TODO: Check required fields
-            return null;
-        }
-
-        /// <inheritdoc/>
-        public override bool WriteToFile(string outfile, bool ignoreblanks = false, bool throwOnError = false)
-        {
-            try
-            {
-                logger.User($"Writing to '{outfile}'...");
-                FileStream fs = File.Create(outfile);
-
-                // If we get back null for some reason, just log and return
-                if (fs == null)
-                {
-                    logger.Warning($"File '{outfile}' could not be created for writing! Please check to see if the file is writable");
-                    return false;
-                }
-
-                StreamWriter sw = new(fs, new UTF8Encoding(false));
-
-                // Write out each of the machines and roms
-                string lastgame = null;
-
-                // Use a sorted list of games to output
-                foreach (string key in Items.SortedKeys)
-                {
-                    ConcurrentList<DatItem> datItems = Items.FilteredItems(key);
-
-                    // If this machine doesn't contain any writable items, skip
-                    if (!ContainsWritable(datItems))
-                        continue;
-
-                    // Resolve the names in the block
-                    datItems = DatItem.ResolveNames(datItems);
-
-                    for (int index = 0; index < datItems.Count; index++)
-                    {
-                        DatItem datItem = datItems[index];
-
-                        // Check for a "null" item
-                        datItem = ProcessNullifiedItem(datItem);
-
-                        // Write out the item if we're using machine names or we're not ignoring
-                        if (!Header.UseRomName || !ShouldIgnore(datItem, ignoreblanks))
-                            WriteDatItem(sw, datItem, lastgame);
-
-                        // Set the new data to compare against
-                        lastgame = datItem.Machine.Name;
-                    }
-                }
-
-                logger.User($"'{outfile}' written!{Environment.NewLine}");
-                sw.Dispose();
-                fs.Dispose();
-            }
-            catch (Exception ex) when (!throwOnError)
-            {
-                logger.Error(ex);
-                return false;
-            }
-
-            return true;
-        }
-
-        /// <summary>
-        /// Write out DatItem using the supplied StreamWriter
-        /// </summary>
-        /// <param name="sw">StreamWriter to output to</param>
-        /// <param name="datItem">DatItem object to be output</param>
-        /// <param name="lastgame">The name of the last game to be output</param>
-        private void WriteDatItem(StreamWriter sw, DatItem datItem, string lastgame)
-        {
-            // Process the item name
-            ProcessItemName(datItem, false, forceRomName: false);
-
-            // Romba mode automatically uses item name
-            if (Header.OutputDepot?.IsActive == true || Header.UseRomName)
-                sw.Write($"{datItem.GetName() ?? string.Empty}\n");
-            else if (!Header.UseRomName && datItem.Machine.Name != lastgame)
-                sw.Write($"{datItem.Machine.Name}\n");
-
-            sw.Flush();
-        }
     }
 }