diff --git a/SabreTools.Library/DatFiles/Listxml.cs b/SabreTools.Library/DatFiles/Listxml.cs
index 4fe5bd7d..b2cb6a31 100644
--- a/SabreTools.Library/DatFiles/Listxml.cs
+++ b/SabreTools.Library/DatFiles/Listxml.cs
@@ -273,7 +273,7 @@ namespace SabreTools.Library.DatFiles
                     case "device":
                         var device = new Device
                         {
-                            DeviceType = reader.GetAttribute("type"),
+                            DeviceType = reader.GetAttribute("type").AsDeviceType(),
                             Tag = reader.GetAttribute("tag"),
                             FixedImage = reader.GetAttribute("fixed_image"),
                             Mandatory = reader.GetAttribute("mandatory"),
@@ -1418,7 +1418,7 @@ namespace SabreTools.Library.DatFiles
                     case ItemType.Device:
                         var device = datItem as Device;
                         xtw.WriteStartElement("device");
-                        xtw.WriteOptionalAttributeString("type", device.DeviceType);
+                        xtw.WriteOptionalAttributeString("type", device.DeviceType.FromDeviceType());
                         xtw.WriteOptionalAttributeString("tag", device.Tag);
                         xtw.WriteOptionalAttributeString("fixed_image", device.FixedImage);
                         xtw.WriteOptionalAttributeString("mandatory", device.Mandatory);
diff --git a/SabreTools.Library/DatFiles/SabreDat.cs b/SabreTools.Library/DatFiles/SabreDat.cs
index d8cb1276..c050ad13 100644
--- a/SabreTools.Library/DatFiles/SabreDat.cs
+++ b/SabreTools.Library/DatFiles/SabreDat.cs
@@ -1321,7 +1321,7 @@ namespace SabreTools.Library.DatFiles
                         var device = datItem as Device;
                         xtw.WriteStartElement("file");
                         xtw.WriteAttributeString("type", "device");
-                        xtw.WriteOptionalAttributeString("type", device.DeviceType);
+                        xtw.WriteOptionalAttributeString("type", device.DeviceType.FromDeviceType());
                         xtw.WriteOptionalAttributeString("tag", device.Tag);
                         xtw.WriteOptionalAttributeString("fixed_image", device.FixedImage);
                         xtw.WriteOptionalAttributeString("mandatory", device.Mandatory);
diff --git a/SabreTools.Library/DatItems/Device.cs b/SabreTools.Library/DatItems/Device.cs
index 02f80ed1..0850a991 100644
--- a/SabreTools.Library/DatItems/Device.cs
+++ b/SabreTools.Library/DatItems/Device.cs
@@ -2,6 +2,7 @@
 using System.Linq;
 
 using SabreTools.Library.Filtering;
+using SabreTools.Library.Tools;
 using Newtonsoft.Json;
 
 namespace SabreTools.Library.DatItems
@@ -18,7 +19,7 @@ namespace SabreTools.Library.DatItems
         /// Device type
         /// </summary>
         [JsonProperty("type", DefaultValueHandling = DefaultValueHandling.Ignore)]
-        public string DeviceType { get; set; }
+        public DeviceType DeviceType { get; set; }
 
         /// <summary>
         /// Device tag
@@ -72,7 +73,7 @@ namespace SabreTools.Library.DatItems
 
             // Handle Device-specific fields
             if (mappings.Keys.Contains(Field.DatItem_DeviceType))
-                DeviceType = mappings[Field.DatItem_DeviceType];
+                DeviceType = mappings[Field.DatItem_DeviceType].AsDeviceType();
 
             if (mappings.Keys.Contains(Field.DatItem_Tag))
                 Tag = mappings[Field.DatItem_Tag];
@@ -199,9 +200,9 @@ namespace SabreTools.Library.DatItems
                 return false;
 
             // Filter on device type
-            if (filter.DatItem_DeviceType.MatchesPositiveSet(DeviceType) == false)
+            if (filter.DatItem_DeviceType.MatchesPositive(DeviceType.NULL, DeviceType) == false)
                 return false;
-            if (filter.DatItem_DeviceType.MatchesNegativeSet(DeviceType) == true)
+            if (filter.DatItem_DeviceType.MatchesNegative(DeviceType.NULL, DeviceType) == true)
                 return false;
 
             // Filter on tag
@@ -262,7 +263,7 @@ namespace SabreTools.Library.DatItems
 
             // Remove the fields
             if (fields.Contains(Field.DatItem_DeviceType))
-                DeviceType = null;
+                DeviceType = DeviceType.NULL;
 
             if (fields.Contains(Field.DatItem_Tag))
                 Tag = null;
diff --git a/SabreTools.Library/DatItems/Enums.cs b/SabreTools.Library/DatItems/Enums.cs
index 48b51988..18a5217b 100644
--- a/SabreTools.Library/DatItems/Enums.cs
+++ b/SabreTools.Library/DatItems/Enums.cs
@@ -45,6 +45,40 @@ namespace SabreTools.Library.DatItems
         Gambling = 1 << 14,
     }
 
+    /// <summary>
+    /// Determine the device type
+    /// </summary>
+    [Flags]
+    public enum DeviceType
+    {
+        /// <summary>
+        /// This is a fake flag that is used for filter only
+        /// </summary>
+        NULL = 0,
+
+        Unknown = 1 << 0,
+        Cartridge = 1 << 1,
+        FloppyDisk = 1 << 2,
+        HardDisk = 1 << 3,
+        Cylinder = 1 << 4,
+        Cassette = 1 << 5,
+        PunchCard = 1 << 6,
+        PunchTape = 1 << 7,
+        Printout = 1 << 8,
+        Serial = 1 << 9,
+        Parallel = 1 << 10,
+        Snapshot = 1 << 11,
+        QuickLoad = 1 << 12,
+        MemCard = 1 << 13,
+        CDROM = 1 << 14,
+        MagTape = 1 << 15,
+        ROMImage = 1 << 16,
+        MIDIIn = 1 << 17,
+        MIDIOut = 1 << 18,
+        Picture = 1 << 19,
+        VidFile = 1 << 20,
+    }
+
     /// <summary>
     /// Determine the display type
     /// </summary>
diff --git a/SabreTools.Library/Filtering/Filter.cs b/SabreTools.Library/Filtering/Filter.cs
index b9482547..13db577a 100644
--- a/SabreTools.Library/Filtering/Filter.cs
+++ b/SabreTools.Library/Filtering/Filter.cs
@@ -189,7 +189,7 @@ namespace SabreTools.Library.Filtering
         public FilterItem<Endianness> DatItem_AreaEndianness { get; private set; } = new FilterItem<Endianness>() { Positive = Endianness.NULL, Negative = Endianness.NULL };
 
         // Device
-        public FilterItem<string> DatItem_DeviceType { get; private set; } = new FilterItem<string>();
+        public FilterItem<DeviceType> DatItem_DeviceType { get; private set; } = new FilterItem<DeviceType>() { Positive = DeviceType.NULL, Negative = DeviceType.NULL };
         public FilterItem<string> DatItem_FixedImage { get; private set; } = new FilterItem<string>();
         public FilterItem<string> DatItem_Mandatory { get; private set; } = new FilterItem<string>();
         public FilterItem<string> DatItem_Interface { get; private set; } = new FilterItem<string>();
@@ -815,7 +815,10 @@ namespace SabreTools.Library.Filtering
 
                 // Device
                 case Field.DatItem_DeviceType:
-                    SetStringFilter(DatItem_DeviceType, value, negate);
+                    if (negate)
+                        DatItem_DeviceType.Negative |= value.AsDeviceType();
+                    else
+                        DatItem_DeviceType.Positive |= value.AsDeviceType();
                     break;
 
                 case Field.DatItem_FixedImage:
diff --git a/SabreTools.Library/Tools/Converters.cs b/SabreTools.Library/Tools/Converters.cs
index fc2fc183..b2b465f7 100644
--- a/SabreTools.Library/Tools/Converters.cs
+++ b/SabreTools.Library/Tools/Converters.cs
@@ -242,6 +242,90 @@ namespace SabreTools.Library.Tools
             }
         }
 
+        /// <summary>
+        /// Get DeviceType value from input string
+        /// </summary>
+        /// <param name="deviceType">String to get value from</param>
+        /// <returns>DeviceType value corresponding to the string</returns>
+        public static DeviceType AsDeviceType(this string deviceType)
+        {
+#if NET_FRAMEWORK
+            switch (deviceType?.ToLowerInvariant())
+            {
+                case "unknown":
+                    return DeviceType.Unknown;
+                case "cartridge":
+                    return DeviceType.Cartridge;
+                case "floppydisk":
+                    return DeviceType.FloppyDisk;
+                case "harddisk":
+                    return DeviceType.HardDisk;
+                case "cylinder":
+                    return DeviceType.Cylinder;
+                case "cassette":
+                    return DeviceType.Cassette;
+                case "punchcard":
+                    return DeviceType.PunchCard;
+                case "punchtape":
+                    return DeviceType.PunchTape;
+                case "printout":
+                    return DeviceType.Printout;
+                case "serial":
+                    return DeviceType.Serial;
+                case "parallel":
+                    return DeviceType.Parallel;
+                case "snapshot":
+                    return DeviceType.Snapshot;
+                case "quickload":
+                    return DeviceType.QuickLoad;
+                case "memcard":
+                    return DeviceType.MemCard;
+                case "cdrom":
+                    return DeviceType.CDROM;
+                case "magtape":
+                    return DeviceType.MagTape;
+                case "romimage":
+                    return DeviceType.ROMImage;
+                case "midiin":
+                    return DeviceType.MIDIIn;
+                case "midiout":
+                    return DeviceType.MIDIOut;
+                case "picture":
+                    return DeviceType.Picture;
+                case "vidfile":
+                    return DeviceType.VidFile;
+                default:
+                    return DeviceType.NULL;
+            }
+#else
+            return deviceType?.ToLowerInvariant() switch
+            {
+                "unknown" => DeviceType.Unknown,
+                "cartridge" => DeviceType.Cartridge,
+                "floppydisk" => DeviceType.FloppyDisk,
+                "harddisk" => DeviceType.HardDisk,
+                "cylinder" => DeviceType.Cylinder,
+                "cassette" => DeviceType.Cassette,
+                "punchcard" => DeviceType.PunchCard,
+                "punchtape" => DeviceType.PunchTape,
+                "printout" => DeviceType.Printout,
+                "serial" => DeviceType.Serial,
+                "parallel" => DeviceType.Parallel,
+                "snapshot" => DeviceType.Snapshot,
+                "quickload" => DeviceType.QuickLoad,
+                "memcard" => DeviceType.MemCard,
+                "cdrom" => DeviceType.CDROM,
+                "magtape" => DeviceType.MagTape,
+                "romimage" => DeviceType.ROMImage,
+                "midiin" => DeviceType.MIDIIn,
+                "midiout" => DeviceType.MIDIOut,
+                "picture" => DeviceType.Picture,
+                "vidfile" => DeviceType.VidFile,
+                _ => DeviceType.NULL,
+            };
+#endif
+        }
+
         /// <summary>
         /// Get DisplayType value from input string
         /// </summary>
@@ -2386,6 +2470,91 @@ namespace SabreTools.Library.Tools
 #endif
         }
 
+        /// <summary>
+        /// Get string value from input DeviceType
+        /// </summary>
+        /// <param name="deviceType">vDeviceType to get value from</param>
+        /// <returns>String value corresponding to the DeviceType</returns>
+        public static string FromDeviceType(this DeviceType deviceType)
+        {
+#if NET_FRAMEWORK
+            switch (deviceType)
+            {
+                case DeviceType.Unknown:
+                    return "unknown";
+                case DeviceType.Cartridge:
+                    return "cartridge";
+                case DeviceType.FloppyDisk:
+                    return "floppydisk";
+                case DeviceType.HardDisk:
+                    return "harddisk";
+                case DeviceType.Cylinder:
+                    return "cylinder";
+                case DeviceType.Cassette:
+                    return "cassette";
+                case DeviceType.PunchCard:
+                    return "punchcard";
+                case DeviceType.PunchTape:
+                    return "punchtape";
+                case DeviceType.Printout:
+                    return "printout";
+                case DeviceType.Serial:
+                    return "serial";
+                case DeviceType.Parallel:
+                    return "parallel";
+                case DeviceType.Snapshot:
+                    return "snapshot";
+                case DeviceType.QuickLoad:
+                    return "quickload";
+                case DeviceType.MemCard:
+                    return "memcard";
+                case DeviceType.CDROM:
+                    return "cdrom";
+                case DeviceType.MagTape:
+                    return "magtape";
+                case DeviceType.ROMImage:
+                    return "romimage";
+                case DeviceType.MIDIIn:
+                    return "midiin";
+                case DeviceType.MIDIOut:
+                    return "midiout";
+                case DeviceType.Picture:
+                    return "picture";
+                case DeviceType.VidFile:
+                    return "vidfile";
+                default:
+                    return null;
+            }
+#else
+            return deviceType switch
+            {
+                DeviceType.Unknown => "unknown",
+                DeviceType.Cartridge => "cartridge",
+                DeviceType.FloppyDisk => "floppydisk",
+                DeviceType.HardDisk => "harddisk",
+                DeviceType.Cylinder => "cylinder",
+                DeviceType.Cassette => "cassette",
+                DeviceType.PunchCard => "punchcard",
+                DeviceType.PunchTape => "punchtape",
+                DeviceType.Printout => "printout",
+                DeviceType.Serial => "serial",
+                DeviceType.Parallel => "parallel",
+                DeviceType.Snapshot => "snapshot",
+                DeviceType.QuickLoad => "quickload",
+                DeviceType.MemCard => "memcard",
+                DeviceType.CDROM => "cdrom",
+                DeviceType.MagTape => "magtape",
+                DeviceType.ROMImage => "romimage",
+                DeviceType.MIDIIn => "midiin",
+                DeviceType.MIDIOut => "midiout",
+                DeviceType.Picture => "picture",
+                DeviceType.VidFile => "vidfile",
+                _ => null,
+            };
+#endif
+        }
+
+
         /// <summary>
         /// Get string value from input DisplayType
         /// </summary>