diff --git a/SabreTools.Serialization.Test/Deserializers/MessTests.cs b/SabreTools.Serialization.Test/Deserializers/MessTests.cs
new file mode 100644
index 00000000..0bfa01ad
--- /dev/null
+++ b/SabreTools.Serialization.Test/Deserializers/MessTests.cs
@@ -0,0 +1,940 @@
+using System.IO;
+using System.Linq;
+using SabreTools.Serialization.Deserializers;
+using Xunit;
+
+namespace SabreTools.Serialization.Test.Deserializers
+{
+    public class MessTests
+    {
+        [Fact]
+        public void NullArray_Null()
+        {
+            byte[]? data = null;
+            int offset = 0;
+            var deserializer = new Mess();
+
+            var actual = deserializer.Deserialize(data, offset);
+            Assert.Null(actual);
+        }
+
+        [Fact]
+        public void EmptyArray_Null()
+        {
+            byte[]? data = [];
+            int offset = 0;
+            var deserializer = new Mess();
+
+            var actual = deserializer.Deserialize(data, offset);
+            Assert.Null(actual);
+        }
+
+        [Fact]
+        public void InvalidArray_Null()
+        {
+            byte[]? data = [.. Enumerable.Repeat<byte>(0xFF, 1024)];
+            int offset = 0;
+            var deserializer = new Mess();
+
+            var actual = deserializer.Deserialize(data, offset);
+            Assert.Null(actual);
+        }
+
+        [Fact]
+        public void NullStream_Null()
+        {
+            Stream? data = null;
+            var deserializer = new Mess();
+
+            var actual = deserializer.Deserialize(data);
+            Assert.Null(actual);
+        }
+
+        [Fact]
+        public void EmptyStream_Null()
+        {
+            Stream? data = new MemoryStream([]);
+            var deserializer = new Mess();
+
+            var actual = deserializer.Deserialize(data);
+            Assert.Null(actual);
+        }
+
+        [Fact]
+        public void InvalidStream_Null()
+        {
+            Stream? data = new MemoryStream([.. Enumerable.Repeat<byte>(0xFF, 1024)]);
+            var deserializer = new Mess();
+
+            var actual = deserializer.Deserialize(data);
+            Assert.Null(actual);
+        }
+
+        [Fact]
+        public void RoundTripGameTest()
+        {
+            // Get the serializer and deserializer
+            var deserializer = new Serialization.Deserializers.Mess();
+            var serializer = new Serialization.Serializers.Mess();
+
+            // Build the data
+            Models.Listxml.Mess m1 = Build(game: true);
+
+            // Serialize to generic model
+            Stream? metadata = serializer.Serialize(m1);
+            Assert.NotNull(metadata);
+
+            // Serialize to stream
+            Models.Listxml.Mess? newMess = deserializer.Deserialize(metadata);
+
+            // Validate the data
+            Assert.NotNull(newMess);
+            Assert.Equal("XXXXXX", newMess.Version);
+
+            Assert.NotNull(newMess.Game);
+            var newGame = Assert.Single(newMess.Game);
+            Validate(newGame);
+        }
+
+        [Fact]
+        public void RoundTripMachineTest()
+        {
+            // Get the serializer and deserializer
+            var deserializer = new Serialization.Deserializers.Mess();
+            var serializer = new Serialization.Serializers.Mess();
+
+            // Build the data
+            Models.Listxml.Mess m1 = Build(game: false);
+
+            // Serialize to generic model
+            Stream? metadata = serializer.Serialize(m1);
+            Assert.NotNull(metadata);
+
+            // Serialize to stream
+            Models.Listxml.Mess? newMess = deserializer.Deserialize(metadata);
+
+            // Validate the data
+            Assert.NotNull(newMess);
+            Assert.Equal("XXXXXX", newMess.Version);
+
+            Assert.NotNull(newMess.Game);
+            var newGame = Assert.Single(newMess.Game);
+            Validate(newGame);
+        }
+
+        /// <summary>
+        /// Build model for serialization and deserialization
+        /// </summary>
+        private static Models.Listxml.Mess Build(bool game)
+        {
+            var biosset = new Models.Listxml.BiosSet
+            {
+                Name = "XXXXXX",
+                Description = "XXXXXX",
+                Default = "XXXXXX",
+            };
+
+            var rom = new Models.Listxml.Rom
+            {
+                Name = "XXXXXX",
+                Bios = "XXXXXX",
+                Size = "XXXXXX",
+                CRC = "XXXXXX",
+                SHA1 = "XXXXXX",
+                Merge = "XXXXXX",
+                Region = "XXXXXX",
+                Offset = "XXXXXX",
+                Status = "XXXXXX",
+                Optional = "XXXXXX",
+                Dispose = "XXXXXX",
+                SoundOnly = "XXXXXX",
+            };
+
+            var disk = new Models.Listxml.Disk
+            {
+                Name = "XXXXXX",
+                MD5 = "XXXXXX",
+                SHA1 = "XXXXXX",
+                Merge = "XXXXXX",
+                Region = "XXXXXX",
+                Index = "XXXXXX",
+                Writable = "XXXXXX",
+                Status = "XXXXXX",
+                Optional = "XXXXXX",
+            };
+
+            var deviceref = new Models.Listxml.DeviceRef
+            {
+                Name = "XXXXXX",
+            };
+
+            var sample = new Models.Listxml.Sample
+            {
+                Name = "XXXXXX",
+            };
+
+            var chip = new Models.Listxml.Chip
+            {
+                Name = "XXXXXX",
+                Tag = "XXXXXX",
+                Type = "XXXXXX",
+                SoundOnly = "XXXXXX",
+                Clock = "XXXXXX",
+            };
+
+            var display = new Models.Listxml.Display
+            {
+                Tag = "XXXXXX",
+                Type = "XXXXXX",
+                Rotate = "XXXXXX",
+                FlipX = "XXXXXX",
+                Width = "XXXXXX",
+                Height = "XXXXXX",
+                Refresh = "XXXXXX",
+                PixClock = "XXXXXX",
+                HTotal = "XXXXXX",
+                HBEnd = "XXXXXX",
+                HBStart = "XXXXXX",
+                VTotal = "XXXXXX",
+                VBEnd = "XXXXXX",
+                VBStart = "XXXXXX",
+            };
+
+            var video = new Models.Listxml.Video
+            {
+                Screen = "XXXXXX",
+                Orientation = "XXXXXX",
+                Width = "XXXXXX",
+                Height = "XXXXXX",
+                AspectX = "XXXXXX",
+                AspectY = "XXXXXX",
+                Refresh = "XXXXXX",
+            };
+
+            var sound = new Models.Listxml.Sound
+            {
+                Channels = "XXXXXX",
+            };
+
+            var control = new Models.Listxml.Control
+            {
+                Type = "XXXXXX",
+                Player = "XXXXXX",
+                Buttons = "XXXXXX",
+                ReqButtons = "XXXXXX",
+                Minimum = "XXXXXX",
+                Maximum = "XXXXXX",
+                Sensitivity = "XXXXXX",
+                KeyDelta = "XXXXXX",
+                Reverse = "XXXXXX",
+                Ways = "XXXXXX",
+                Ways2 = "XXXXXX",
+                Ways3 = "XXXXXX",
+            };
+
+            var input = new Models.Listxml.Input
+            {
+                Service = "XXXXXX",
+                Tilt = "XXXXXX",
+                Players = "XXXXXX",
+                //ControlAttr = "XXXXXX", // Mututally exclusive with input.Control
+                Buttons = "XXXXXX",
+                Coins = "XXXXXX",
+                Control = [control],
+            };
+
+            var condition = new Models.Listxml.Condition
+            {
+                Tag = "XXXXXX",
+                Mask = "XXXXXX",
+                Relation = "XXXXXX",
+                Value = "XXXXXX",
+            };
+
+            var diplocation = new Models.Listxml.DipLocation
+            {
+                Name = "XXXXXX",
+                Number = "XXXXXX",
+                Inverted = "XXXXXX",
+            };
+
+            var dipvalue = new Models.Listxml.DipValue
+            {
+                Name = "XXXXXX",
+                Value = "XXXXXX",
+                Default = "XXXXXX",
+                Condition = condition,
+            };
+
+            var dipswitch = new Models.Listxml.DipSwitch
+            {
+                Name = "XXXXXX",
+                Tag = "XXXXXX",
+                Mask = "XXXXXX",
+                Condition = condition,
+                DipLocation = [diplocation],
+                DipValue = [dipvalue],
+            };
+
+            var conflocation = new Models.Listxml.ConfLocation
+            {
+                Name = "XXXXXX",
+                Number = "XXXXXX",
+                Inverted = "XXXXXX",
+            };
+
+            var confsetting = new Models.Listxml.ConfSetting
+            {
+                Name = "XXXXXX",
+                Value = "XXXXXX",
+                Default = "XXXXXX",
+                Condition = condition,
+            };
+
+            var configuration = new Models.Listxml.Configuration
+            {
+                Name = "XXXXXX",
+                Tag = "XXXXXX",
+                Mask = "XXXXXX",
+                Condition = condition,
+                ConfLocation = [conflocation],
+                ConfSetting = [confsetting],
+            };
+
+            var analog = new Models.Listxml.Analog
+            {
+                Mask = "XXXXXX",
+            };
+
+            var port = new Models.Listxml.Port
+            {
+                Tag = "XXXXXX",
+                Analog = [analog],
+            };
+
+            var adjuster = new Models.Listxml.Adjuster
+            {
+                Name = "XXXXXX",
+                Default = "XXXXXX",
+                Condition = condition,
+            };
+
+            var driver = new Models.Listxml.Driver
+            {
+                Status = "XXXXXX",
+                Color = "XXXXXX",
+                Sound = "XXXXXX",
+                PaletteSize = "XXXXXX",
+                Emulation = "XXXXXX",
+                Cocktail = "XXXXXX",
+                SaveState = "XXXXXX",
+                RequiresArtwork = "XXXXXX",
+                Unofficial = "XXXXXX",
+                NoSoundHardware = "XXXXXX",
+                Incomplete = "XXXXXX",
+            };
+
+            var feature = new Models.Listxml.Feature
+            {
+                Type = "XXXXXX",
+                Status = "XXXXXX",
+                Overall = "XXXXXX",
+            };
+
+            var instance = new Models.Listxml.Instance
+            {
+                Name = "XXXXXX",
+                BriefName = "XXXXXX",
+            };
+
+            var extension = new Models.Listxml.Extension
+            {
+                Name = "XXXXXX",
+            };
+
+            var device = new Models.Listxml.Device
+            {
+                Type = "XXXXXX",
+                Tag = "XXXXXX",
+                FixedImage = "XXXXXX",
+                Mandatory = "XXXXXX",
+                Interface = "XXXXXX",
+                Instance = instance,
+                Extension = [extension],
+            };
+
+            var slotOption = new Models.Listxml.SlotOption
+            {
+                Name = "XXXXXX",
+                DevName = "XXXXXX",
+                Default = "XXXXXX",
+            };
+
+            var slot = new Models.Listxml.Slot
+            {
+                Name = "XXXXXX",
+                SlotOption = [slotOption],
+            };
+
+            var softwarelist = new Models.Listxml.SoftwareList
+            {
+                Tag = "XXXXXX",
+                Name = "XXXXXX",
+                Status = "XXXXXX",
+                Filter = "XXXXXX",
+            };
+
+            var ramoption = new Models.Listxml.RamOption
+            {
+                Name = "XXXXXX",
+                Default = "XXXXXX",
+                Content = "XXXXXX",
+            };
+
+            Models.Listxml.GameBase gameBase = game
+                ? new Models.Listxml.Game()
+                : new Models.Listxml.Machine();
+            gameBase.Name = "XXXXXX";
+            gameBase.SourceFile = "XXXXXX";
+            gameBase.IsBios = "XXXXXX";
+            gameBase.IsDevice = "XXXXXX";
+            gameBase.IsMechanical = "XXXXXX";
+            gameBase.Runnable = "XXXXXX";
+            gameBase.CloneOf = "XXXXXX";
+            gameBase.RomOf = "XXXXXX";
+            gameBase.SampleOf = "XXXXXX";
+            gameBase.Description = "XXXXXX";
+            gameBase.Year = "XXXXXX";
+            gameBase.Manufacturer = "XXXXXX";
+            gameBase.History = "XXXXXX";
+            gameBase.BiosSet = [biosset];
+            gameBase.Rom = [rom];
+            gameBase.Disk = [disk];
+            gameBase.DeviceRef = [deviceref];
+            gameBase.Sample = [sample];
+            gameBase.Chip = [chip];
+            gameBase.Display = [display];
+            gameBase.Video = [video];
+            gameBase.Sound = sound;
+            gameBase.Input = input;
+            gameBase.DipSwitch = [dipswitch];
+            gameBase.Configuration = [configuration];
+            gameBase.Port = [port];
+            gameBase.Adjuster = [adjuster];
+            gameBase.Driver = driver;
+            gameBase.Feature = [feature];
+            gameBase.Device = [device];
+            gameBase.Slot = [slot];
+            gameBase.SoftwareList = [softwarelist];
+            gameBase.RamOption = [ramoption];
+
+            return new Models.Listxml.Mess
+            {
+                Version = "XXXXXX",
+                Game = [gameBase],
+            };
+        }
+
+        /// <summary>
+        /// Validate a GameBase
+        /// </summary>
+        private static void Validate(Models.Listxml.GameBase? gb)
+        {
+            Assert.NotNull(gb);
+            Assert.Equal("XXXXXX", gb.Name);
+            Assert.Equal("XXXXXX", gb.SourceFile);
+            Assert.Equal("XXXXXX", gb.IsBios);
+            Assert.Equal("XXXXXX", gb.IsDevice);
+            Assert.Equal("XXXXXX", gb.IsMechanical);
+            Assert.Equal("XXXXXX", gb.Runnable);
+            Assert.Equal("XXXXXX", gb.CloneOf);
+            Assert.Equal("XXXXXX", gb.RomOf);
+            Assert.Equal("XXXXXX", gb.SampleOf);
+            Assert.Equal("XXXXXX", gb.Description);
+            Assert.Equal("XXXXXX", gb.Year);
+            Assert.Equal("XXXXXX", gb.Manufacturer);
+            Assert.Equal("XXXXXX", gb.History);
+
+            Assert.NotNull(gb.BiosSet);
+            var biosset = Assert.Single(gb.BiosSet);
+            Validate(biosset);
+
+            Assert.NotNull(gb.Rom);
+            var rom = Assert.Single(gb.Rom);
+            Validate(rom);
+
+            Assert.NotNull(gb.Disk);
+            var disk = Assert.Single(gb.Disk);
+            Validate(disk);
+
+            Assert.NotNull(gb.DeviceRef);
+            var deviceref = Assert.Single(gb.DeviceRef);
+            Validate(deviceref);
+
+            Assert.NotNull(gb.Sample);
+            var sample = Assert.Single(gb.Sample);
+            Validate(sample);
+
+            Assert.NotNull(gb.Chip);
+            var chip = Assert.Single(gb.Chip);
+            Validate(chip);
+
+            Assert.NotNull(gb.Display);
+            var display = Assert.Single(gb.Display);
+            Validate(display);
+
+            Assert.NotNull(gb.Video);
+            var video = Assert.Single(gb.Video);
+            Validate(video);
+
+            Validate(gb.Sound);
+            Validate(gb.Input);
+
+            Assert.NotNull(gb.DipSwitch);
+            var dipswitch = Assert.Single(gb.DipSwitch);
+            Validate(dipswitch);
+
+            Assert.NotNull(gb.Configuration);
+            var configuration = Assert.Single(gb.Configuration);
+            Validate(configuration);
+
+            Assert.NotNull(gb.Port);
+            var port = Assert.Single(gb.Port);
+            Validate(port);
+
+            Assert.NotNull(gb.Adjuster);
+            var adjuster = Assert.Single(gb.Adjuster);
+            Validate(adjuster);
+
+            Validate(gb.Driver);
+
+            Assert.NotNull(gb.Feature);
+            var feature = Assert.Single(gb.Feature);
+            Validate(feature);
+
+            Assert.NotNull(gb.Device);
+            var device = Assert.Single(gb.Device);
+            Validate(device);
+
+            Assert.NotNull(gb.Slot);
+            var slot = Assert.Single(gb.Slot);
+            Validate(slot);
+
+            Assert.NotNull(gb.SoftwareList);
+            var softwarelist = Assert.Single(gb.SoftwareList);
+            Validate(softwarelist);
+
+            Assert.NotNull(gb.RamOption);
+            var ramoption = Assert.Single(gb.RamOption);
+            Validate(ramoption);
+        }
+
+        /// <summary>
+        /// Validate a BiosSet
+        /// </summary>
+        private static void Validate(Models.Listxml.BiosSet? biosset)
+        {
+            Assert.NotNull(biosset);
+            Assert.Equal("XXXXXX", biosset.Name);
+            Assert.Equal("XXXXXX", biosset.Description);
+            Assert.Equal("XXXXXX", biosset.Default);
+        }
+
+        /// <summary>
+        /// Validate a Rom
+        /// </summary>
+        private static void Validate(Models.Listxml.Rom? rom)
+        {
+            Assert.NotNull(rom);
+            Assert.Equal("XXXXXX", rom.Name);
+            Assert.Equal("XXXXXX", rom.Bios);
+            Assert.Equal("XXXXXX", rom.Size);
+            Assert.Equal("XXXXXX", rom.CRC);
+            Assert.Equal("XXXXXX", rom.SHA1);
+            Assert.Equal("XXXXXX", rom.Merge);
+            Assert.Equal("XXXXXX", rom.Region);
+            Assert.Equal("XXXXXX", rom.Offset);
+            Assert.Equal("XXXXXX", rom.Status);
+            Assert.Equal("XXXXXX", rom.Optional);
+            Assert.Equal("XXXXXX", rom.Dispose);
+            Assert.Equal("XXXXXX", rom.SoundOnly);
+        }
+
+        /// <summary>
+        /// Validate a Disk
+        /// </summary>
+        private static void Validate(Models.Listxml.Disk? disk)
+        {
+            Assert.NotNull(disk);
+            Assert.Equal("XXXXXX", disk.Name);
+            Assert.Equal("XXXXXX", disk.MD5);
+            Assert.Equal("XXXXXX", disk.SHA1);
+            Assert.Equal("XXXXXX", disk.Merge);
+            Assert.Equal("XXXXXX", disk.Region);
+            Assert.Equal("XXXXXX", disk.Index);
+            Assert.Equal("XXXXXX", disk.Writable);
+            Assert.Equal("XXXXXX", disk.Status);
+            Assert.Equal("XXXXXX", disk.Optional);
+        }
+
+        /// <summary>
+        /// Validate a DeviceRef
+        /// </summary>
+        private static void Validate(Models.Listxml.DeviceRef? deviceref)
+        {
+            Assert.NotNull(deviceref);
+            Assert.Equal("XXXXXX", deviceref.Name);
+        }
+
+        /// <summary>
+        /// Validate a Sample
+        /// </summary>
+        private static void Validate(Models.Listxml.Sample? sample)
+        {
+            Assert.NotNull(sample);
+            Assert.Equal("XXXXXX", sample.Name);
+        }
+
+        /// <summary>
+        /// Validate a Chip
+        /// </summary>
+        private static void Validate(Models.Listxml.Chip? chip)
+        {
+            Assert.NotNull(chip);
+            Assert.Equal("XXXXXX", chip.Name);
+            Assert.Equal("XXXXXX", chip.Tag);
+            Assert.Equal("XXXXXX", chip.Type);
+            Assert.Equal("XXXXXX", chip.SoundOnly);
+            Assert.Equal("XXXXXX", chip.Clock);
+        }
+
+        /// <summary>
+        /// Validate a Display
+        /// </summary>
+        private static void Validate(Models.Listxml.Display? display)
+        {
+            Assert.NotNull(display);
+            Assert.Equal("XXXXXX", display.Tag);
+            Assert.Equal("XXXXXX", display.Type);
+            Assert.Equal("XXXXXX", display.Rotate);
+            Assert.Equal("XXXXXX", display.FlipX);
+            Assert.Equal("XXXXXX", display.Width);
+            Assert.Equal("XXXXXX", display.Height);
+            Assert.Equal("XXXXXX", display.Refresh);
+            Assert.Equal("XXXXXX", display.PixClock);
+            Assert.Equal("XXXXXX", display.HTotal);
+            Assert.Equal("XXXXXX", display.HBEnd);
+            Assert.Equal("XXXXXX", display.HBStart);
+            Assert.Equal("XXXXXX", display.VTotal);
+            Assert.Equal("XXXXXX", display.VBEnd);
+            Assert.Equal("XXXXXX", display.VBStart);
+        }
+
+        /// <summary>
+        /// Validate a Video
+        /// </summary>
+        private static void Validate(Models.Listxml.Video? video)
+        {
+            Assert.NotNull(video);
+            Assert.Equal("XXXXXX", video.Screen);
+            Assert.Equal("XXXXXX", video.Orientation);
+            Assert.Equal("XXXXXX", video.Width);
+            Assert.Equal("XXXXXX", video.Height);
+            Assert.Equal("XXXXXX", video.AspectX);
+            Assert.Equal("XXXXXX", video.AspectY);
+            Assert.Equal("XXXXXX", video.Refresh);
+        }
+
+        /// <summary>
+        /// Validate a Sound
+        /// </summary>
+        private static void Validate(Models.Listxml.Sound? sound)
+        {
+            Assert.NotNull(sound);
+            Assert.Equal("XXXXXX", sound.Channels);
+        }
+
+        /// <summary>
+        /// Validate a Input
+        /// </summary>
+        private static void Validate(Models.Listxml.Input? input)
+        {
+            Assert.NotNull(input);
+            Assert.Equal("XXXXXX", input.Service);
+            Assert.Equal("XXXXXX", input.Tilt);
+            Assert.Equal("XXXXXX", input.Players);
+            //Assert.Equal("XXXXXX", input.ControlAttr); // Mututally exclusive with input.Control
+            Assert.Equal("XXXXXX", input.Buttons);
+            Assert.Equal("XXXXXX", input.Coins);
+
+            Assert.NotNull(input.Control);
+            var control = Assert.Single(input.Control);
+            Validate(control);
+        }
+
+        /// <summary>
+        /// Validate a Control
+        /// </summary>
+        private static void Validate(Models.Listxml.Control? control)
+        {
+            Assert.NotNull(control);
+            Assert.Equal("XXXXXX", control.Type);
+            Assert.Equal("XXXXXX", control.Player);
+            Assert.Equal("XXXXXX", control.Buttons);
+            Assert.Equal("XXXXXX", control.ReqButtons);
+            Assert.Equal("XXXXXX", control.Minimum);
+            Assert.Equal("XXXXXX", control.Maximum);
+            Assert.Equal("XXXXXX", control.Sensitivity);
+            Assert.Equal("XXXXXX", control.KeyDelta);
+            Assert.Equal("XXXXXX", control.Reverse);
+            Assert.Equal("XXXXXX", control.Ways);
+            Assert.Equal("XXXXXX", control.Ways2);
+            Assert.Equal("XXXXXX", control.Ways3);
+        }
+
+        /// <summary>
+        /// Validate a DipSwitch
+        /// </summary>
+        private static void Validate(Models.Listxml.DipSwitch? dipswitch)
+        {
+            Assert.NotNull(dipswitch);
+            Assert.Equal("XXXXXX", dipswitch.Name);
+            Assert.Equal("XXXXXX", dipswitch.Tag);
+            Assert.Equal("XXXXXX", dipswitch.Mask);
+            Validate(dipswitch.Condition);
+
+            Assert.NotNull(dipswitch.DipLocation);
+            var diplocation = Assert.Single(dipswitch.DipLocation);
+            Validate(diplocation);
+
+            Assert.NotNull(dipswitch.DipValue);
+            var dipvalue = Assert.Single(dipswitch.DipValue);
+            Validate(dipvalue);
+        }
+
+        /// <summary>
+        /// Validate a Condition
+        /// </summary>
+        private static void Validate(Models.Listxml.Condition? condition)
+        {
+            Assert.NotNull(condition);
+            Assert.Equal("XXXXXX", condition.Tag);
+            Assert.Equal("XXXXXX", condition.Mask);
+            Assert.Equal("XXXXXX", condition.Relation);
+            Assert.Equal("XXXXXX", condition.Value);
+        }
+
+        /// <summary>
+        /// Validate a DipLocation
+        /// </summary>
+        private static void Validate(Models.Listxml.DipLocation? diplocation)
+        {
+            Assert.NotNull(diplocation);
+            Assert.Equal("XXXXXX", diplocation.Name);
+            Assert.Equal("XXXXXX", diplocation.Number);
+            Assert.Equal("XXXXXX", diplocation.Inverted);
+        }
+
+        /// <summary>
+        /// Validate a DipValue
+        /// </summary>
+        private static void Validate(Models.Listxml.DipValue? dipvalue)
+        {
+            Assert.NotNull(dipvalue);
+            Assert.Equal("XXXXXX", dipvalue.Name);
+            Assert.Equal("XXXXXX", dipvalue.Value);
+            Assert.Equal("XXXXXX", dipvalue.Default);
+            Validate(dipvalue.Condition);
+        }
+
+        /// <summary>
+        /// Validate a Configuration
+        /// </summary>
+        private static void Validate(Models.Listxml.Configuration? configuration)
+        {
+            Assert.NotNull(configuration);
+            Assert.Equal("XXXXXX", configuration.Name);
+            Assert.Equal("XXXXXX", configuration.Tag);
+            Assert.Equal("XXXXXX", configuration.Mask);
+            Validate(configuration.Condition);
+
+            Assert.NotNull(configuration.ConfLocation);
+            var conflocation = Assert.Single(configuration.ConfLocation);
+            Validate(conflocation);
+
+            Assert.NotNull(configuration.ConfSetting);
+            var confsetting = Assert.Single(configuration.ConfSetting);
+            Validate(confsetting);
+        }
+
+        /// <summary>
+        /// Validate a ConfLocation
+        /// </summary>
+        private static void Validate(Models.Listxml.ConfLocation? conflocation)
+        {
+            Assert.NotNull(conflocation);
+            Assert.Equal("XXXXXX", conflocation.Name);
+            Assert.Equal("XXXXXX", conflocation.Number);
+            Assert.Equal("XXXXXX", conflocation.Inverted);
+        }
+
+        /// <summary>
+        /// Validate a ConfSetting
+        /// </summary>
+        private static void Validate(Models.Listxml.ConfSetting? confsetting)
+        {
+            Assert.NotNull(confsetting);
+            Assert.Equal("XXXXXX", confsetting.Name);
+            Assert.Equal("XXXXXX", confsetting.Value);
+            Assert.Equal("XXXXXX", confsetting.Default);
+            Validate(confsetting.Condition);
+        }
+
+        /// <summary>
+        /// Validate a Port
+        /// </summary>
+        private static void Validate(Models.Listxml.Port? port)
+        {
+            Assert.NotNull(port);
+            Assert.Equal("XXXXXX", port.Tag);
+
+            Assert.NotNull(port.Analog);
+            var analog = Assert.Single(port.Analog);
+            Validate(analog);
+        }
+
+        /// <summary>
+        /// Validate a Analog
+        /// </summary>
+        private static void Validate(Models.Listxml.Analog? analog)
+        {
+            Assert.NotNull(analog);
+            Assert.Equal("XXXXXX", analog.Mask);
+        }
+
+        /// <summary>
+        /// Validate a Adjuster
+        /// </summary>
+        private static void Validate(Models.Listxml.Adjuster? adjuster)
+        {
+            Assert.NotNull(adjuster);
+            Assert.Equal("XXXXXX", adjuster.Name);
+            Assert.Equal("XXXXXX", adjuster.Default);
+            Validate(adjuster.Condition);
+        }
+
+        /// <summary>
+        /// Validate a Driver
+        /// </summary>
+        private static void Validate(Models.Listxml.Driver? driver)
+        {
+            Assert.NotNull(driver);
+            Assert.Equal("XXXXXX", driver.Status);
+            Assert.Equal("XXXXXX", driver.Color);
+            Assert.Equal("XXXXXX", driver.Sound);
+            Assert.Equal("XXXXXX", driver.PaletteSize);
+            Assert.Equal("XXXXXX", driver.Emulation);
+            Assert.Equal("XXXXXX", driver.Cocktail);
+            Assert.Equal("XXXXXX", driver.SaveState);
+            Assert.Equal("XXXXXX", driver.RequiresArtwork);
+            Assert.Equal("XXXXXX", driver.Unofficial);
+            Assert.Equal("XXXXXX", driver.NoSoundHardware);
+            Assert.Equal("XXXXXX", driver.Incomplete);
+        }
+
+        /// <summary>
+        /// Validate a Feature
+        /// </summary>
+        private static void Validate(Models.Listxml.Feature? feature)
+        {
+            Assert.NotNull(feature);
+            Assert.Equal("XXXXXX", feature.Type);
+            Assert.Equal("XXXXXX", feature.Status);
+            Assert.Equal("XXXXXX", feature.Overall);
+        }
+
+        /// <summary>
+        /// Validate a Device
+        /// </summary>
+        private static void Validate(Models.Listxml.Device? device)
+        {
+            Assert.NotNull(device);
+            Assert.Equal("XXXXXX", device.Type);
+            Assert.Equal("XXXXXX", device.Tag);
+            Assert.Equal("XXXXXX", device.FixedImage);
+            Assert.Equal("XXXXXX", device.Mandatory);
+            Assert.Equal("XXXXXX", device.Interface);
+            Validate(device.Instance);
+
+            Assert.NotNull(device.Extension);
+            var extension = Assert.Single(device.Extension);
+            Validate(extension);
+        }
+
+        /// <summary>
+        /// Validate a Instance
+        /// </summary>
+        private static void Validate(Models.Listxml.Instance? instance)
+        {
+            Assert.NotNull(instance);
+            Assert.Equal("XXXXXX", instance.Name);
+            Assert.Equal("XXXXXX", instance.BriefName);
+        }
+
+        /// <summary>
+        /// Validate a Extension
+        /// </summary>
+        private static void Validate(Models.Listxml.Extension? extension)
+        {
+            Assert.NotNull(extension);
+            Assert.Equal("XXXXXX", extension.Name);
+        }
+
+        /// <summary>
+        /// Validate a Slot
+        /// </summary>
+        private static void Validate(Models.Listxml.Slot? slot)
+        {
+            Assert.NotNull(slot);
+            Assert.Equal("XXXXXX", slot.Name);
+
+            Assert.NotNull(slot.SlotOption);
+            var slotoption = Assert.Single(slot.SlotOption);
+            Validate(slotoption);
+        }
+
+        /// <summary>
+        /// Validate a SlotOption
+        /// </summary>
+        private static void Validate(Models.Listxml.SlotOption? slotoption)
+        {
+            Assert.NotNull(slotoption);
+            Assert.Equal("XXXXXX", slotoption.Name);
+            Assert.Equal("XXXXXX", slotoption.DevName);
+            Assert.Equal("XXXXXX", slotoption.Default);
+        }
+
+        /// <summary>
+        /// Validate a SoftwareList
+        /// </summary>
+        private static void Validate(Models.Listxml.SoftwareList? softwarelist)
+        {
+            Assert.NotNull(softwarelist);
+            Assert.Equal("XXXXXX", softwarelist.Tag);
+            Assert.Equal("XXXXXX", softwarelist.Name);
+            Assert.Equal("XXXXXX", softwarelist.Status);
+            Assert.Equal("XXXXXX", softwarelist.Filter);
+        }
+
+        /// <summary>
+        /// Validate a RamOption
+        /// </summary>
+        private static void Validate(Models.Listxml.RamOption? ramoption)
+        {
+            Assert.NotNull(ramoption);
+            Assert.Equal("XXXXXX", ramoption.Name);
+            Assert.Equal("XXXXXX", ramoption.Default);
+            Assert.Equal("XXXXXX", ramoption.Content);
+        }
+    }
+}
\ No newline at end of file
diff --git a/SabreTools.Serialization.Test/Serializers/MessTests.cs b/SabreTools.Serialization.Test/Serializers/MessTests.cs
new file mode 100644
index 00000000..f6e1b6bb
--- /dev/null
+++ b/SabreTools.Serialization.Test/Serializers/MessTests.cs
@@ -0,0 +1,25 @@
+using System.IO;
+using SabreTools.Serialization.Serializers;
+using Xunit;
+
+namespace SabreTools.Serialization.Test.Serializers
+{
+    public class MessTests
+    {
+        [Fact]
+        public void SerializeArray_Null_Null()
+        {
+            var serializer = new Mess();
+            byte[]? actual = serializer.SerializeArray(null);
+            Assert.Null(actual);
+        }
+
+        [Fact]
+        public void SerializeStream_Null_Null()
+        {
+            var serializer = new Mess();
+            Stream? actual = serializer.Serialize(null);
+            Assert.Null(actual);
+        }
+    }
+}
\ No newline at end of file
diff --git a/SabreTools.Serialization/CrossModel/Mess.Deserializer.cs b/SabreTools.Serialization/CrossModel/Mess.Deserializer.cs
new file mode 100644
index 00000000..2156fac5
--- /dev/null
+++ b/SabreTools.Serialization/CrossModel/Mess.Deserializer.cs
@@ -0,0 +1,36 @@
+using System;
+using SabreTools.Serialization.Interfaces;
+
+namespace SabreTools.Serialization.CrossModel
+{
+    public partial class Mess : IModelSerializer<Models.Listxml.Mess, Models.Metadata.MetadataFile>
+    {
+        /// <inheritdoc/>
+        public Models.Listxml.Mess? Deserialize(Models.Metadata.MetadataFile? obj)
+        {
+            if (obj == null)
+                return null;
+
+            var header = obj.Read<Models.Metadata.Header>(Models.Metadata.MetadataFile.HeaderKey);
+            var m1 = header != null ? ConvertMessFromInternalModel(header) : new Models.Listxml.Mess();
+
+            var machines = obj.Read<Models.Metadata.Machine[]>(Models.Metadata.MetadataFile.MachineKey);
+            if (machines != null && machines.Length > 0)
+                m1.Game = Array.ConvertAll(machines, Listxml.ConvertMachineFromInternalModel);
+
+            return m1;
+        }
+
+        /// <summary>
+        /// Convert from <see cref="Models.Metadata.Models.Metadata.Header"/> to <see cref="Models.Listxml.Mess"/>
+        /// </summary>
+        private static Models.Listxml.Mess ConvertMessFromInternalModel(Models.Metadata.Header item)
+        {
+            var m1 = new Models.Listxml.Mess
+            {
+                Version = item.ReadString(Models.Metadata.Header.VersionKey),
+            };
+            return m1;
+        }
+    }
+}
diff --git a/SabreTools.Serialization/CrossModel/Mess.Serializer.cs b/SabreTools.Serialization/CrossModel/Mess.Serializer.cs
new file mode 100644
index 00000000..4afcb57f
--- /dev/null
+++ b/SabreTools.Serialization/CrossModel/Mess.Serializer.cs
@@ -0,0 +1,40 @@
+using System;
+using SabreTools.Serialization.Interfaces;
+
+namespace SabreTools.Serialization.CrossModel
+{
+    public partial class Mess : IModelSerializer<Models.Listxml.Mess, Models.Metadata.MetadataFile>
+    {
+        /// <inheritdoc/>
+        public Models.Metadata.MetadataFile? Serialize(Models.Listxml.Mess? item)
+        {
+            if (item == null)
+                return null;
+
+            var metadataFile = new Models.Metadata.MetadataFile
+            {
+                [Models.Metadata.MetadataFile.HeaderKey] = ConvertHeaderToInternalModel(item),
+            };
+
+            if (item?.Game != null && item.Game.Length > 0)
+            {
+                metadataFile[Models.Metadata.MetadataFile.MachineKey]
+                    = Array.ConvertAll(item.Game, Listxml.ConvertMachineToInternalModel);
+            }
+
+            return metadataFile;
+        }
+
+        /// <summary>
+        /// Convert from <see cref="Models.Listxml.Mess"/> to <see cref="Models.Metadata.Header"/>
+        /// </summary>
+        private static Models.Metadata.Header ConvertHeaderToInternalModel(Models.Listxml.Mess item)
+        {
+            var header = new Models.Metadata.Header
+            {
+                [Models.Metadata.Header.VersionKey] = item.Version,
+            };
+            return header;
+        }
+    }
+}
diff --git a/SabreTools.Serialization/Deserializers/Mess.cs b/SabreTools.Serialization/Deserializers/Mess.cs
new file mode 100644
index 00000000..27668bb8
--- /dev/null
+++ b/SabreTools.Serialization/Deserializers/Mess.cs
@@ -0,0 +1,7 @@
+namespace SabreTools.Serialization.Deserializers
+{
+    public class Mess : XmlFile<Models.Listxml.Mess>
+    {
+        // All logic taken care of in the base class
+    }
+}
diff --git a/SabreTools.Serialization/Serializers/Mess.cs b/SabreTools.Serialization/Serializers/Mess.cs
new file mode 100644
index 00000000..b9a11f92
--- /dev/null
+++ b/SabreTools.Serialization/Serializers/Mess.cs
@@ -0,0 +1,7 @@
+namespace SabreTools.Serialization.Serializers
+{
+    public class Mess : XmlFile<Models.Listxml.Mess>
+    {
+        // All logic taken care of in the base class
+    }
+}