diff --git a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
index a0894e0201..6738488470 100644
--- a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
+++ b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
@@ -635,6 +635,7 @@
     <Compile Include="Consoles\Nintendo\NES\BisqAPU.cs" />
     <Compile Include="Consoles\Nintendo\NES\FDS\FDS.cs" />
     <Compile Include="Consoles\Nintendo\NES\FDS\FDSAudio.cs" />
+    <Compile Include="Consoles\Nintendo\NES\FDS\FDSInspector.cs" />
     <Compile Include="Consoles\Nintendo\NES\FDS\RamAdapter.cs" />
     <Compile Include="Consoles\Nintendo\NES\INESPPUViewable.cs" />
     <Compile Include="Consoles\Nintendo\NES\NES.BoardSystem.cs" />
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/FDS/FDSInspector.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/FDS/FDSInspector.cs
new file mode 100644
index 0000000000..7000ba54a3
--- /dev/null
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/FDS/FDSInspector.cs
@@ -0,0 +1,191 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.IO;
+
+namespace BizHawk.Emulation.Cores.Nintendo.NES
+{
+	internal static class FTXT
+	{
+		public static readonly Encoding E = Encoding.GetEncoding("ISO-8859-1");
+	}
+
+	public class FDSFile
+	{
+		static byte[] Check = FTXT.E.GetBytes("FDS\x1a");
+		static byte[] CheckAlt = FTXT.E.GetBytes("\x01*NIN");
+
+		public List<FDSDisk> Disks = new List<FDSDisk>();
+
+		public byte[] ExtraData;
+
+		public FDSFile(BinaryReader r)
+		{
+			byte[] tmp = r.ReadBytes(4);
+			int numdisks;
+			if (tmp.SequenceEqual(Check))
+			{
+				numdisks = r.ReadByte();
+				ExtraData = r.ReadBytes(11);
+			}
+			else if (tmp.SequenceEqual(CheckAlt))
+			{
+				// compensate (won't write identically)
+				r.BaseStream.Seek(0, SeekOrigin.Begin);
+				numdisks = (int)(r.BaseStream.Length / 65500);
+				ExtraData = new byte[11];
+			}
+			else
+			{
+				throw new InvalidOperationException("Bad Header!");
+			}
+			if (r.BaseStream.Length - r.BaseStream.Position != numdisks * 65500)
+				throw new InvalidOperationException("Bad File Length!");
+			while (numdisks > 0)
+			{
+				Disks.Add(new FDSDisk(r));
+				numdisks--;
+			}
+		}
+
+		public void Write(BinaryWriter w)
+		{
+			w.Write(Check);
+			w.Write((byte)Disks.Count);
+			w.Write(ExtraData);
+			foreach (var disk in Disks)
+				disk.Write(w);
+		}
+	}
+
+	public class FDSDisk
+	{
+		static byte[] Check = FTXT.E.GetBytes("*NINTENDO-HVC*");
+
+		public List<FDSChunk> Chunks = new List<FDSChunk>();
+
+		public byte[] HeaderData;
+		public byte[] ExtraData;
+
+		public FDSDisk(BinaryReader r)
+		{
+			long startpos = r.BaseStream.Position;
+			long endpos = startpos + 65500;
+
+			if (r.ReadByte() != 1)
+				throw new InvalidOperationException("Bad Block Code");
+
+			if (!r.ReadBytes(14).SequenceEqual(Check))
+				throw new InvalidOperationException("Bad Verification Code");
+
+			// one could do quite a bit with this data
+			HeaderData = r.ReadBytes(41);
+
+			if (r.ReadByte() != 2)
+				throw new InvalidOperationException("Bad Block Code");
+
+			int nfiles = r.ReadByte();
+
+			while (nfiles > 0)
+			{
+				Chunks.Add(new FDSChunk(r));
+				nfiles--;
+			}
+			if (r.BaseStream.Position > endpos)
+				throw new InvalidOperationException("Disk too long");
+
+			long usedpos = r.BaseStream.Position;
+			while (true)
+			{
+				try
+				{
+					var chunk = new FDSChunk(r) { Hidden = true };
+					if (r.BaseStream.Position <= endpos)
+					{
+						Chunks.Add(chunk);
+						usedpos = r.BaseStream.Position;
+					}
+					else
+					{
+						break;
+					}
+				}
+				catch { break; }
+			}
+
+			r.BaseStream.Seek(usedpos, SeekOrigin.Begin);
+			ExtraData = r.ReadBytes((int)(endpos - usedpos));
+		}
+
+		public void Write(BinaryWriter w)
+		{
+			w.Write((byte)1);
+			w.Write(Check);
+			w.Write(HeaderData);
+			w.Write((byte)2);
+			w.Write((byte)Chunks.Count(c => !c.Hidden));
+			foreach (var chunk in Chunks)
+			{
+				chunk.Write(w);
+			}
+			w.Write(ExtraData);
+		}
+	}
+
+	public class FDSChunk
+	{
+		/// <summary>
+		/// true if BIOS will ignore this file.  this flag is not directly stored.
+		/// </summary>
+		public bool Hidden;
+
+		public enum FileKindE : byte
+		{
+			PRAM = 0,
+			CRAM = 1,
+			VRAM = 2
+		}
+
+		public byte Number;
+		public byte ID;
+		public string Name;
+		public ushort Address;
+
+		public FileKindE FileKind;
+		public byte[] Data;
+
+		public FDSChunk(BinaryReader r)
+		{
+			if (r.ReadByte() != 3)
+				throw new InvalidOperationException("Bad Block Code");
+			Number = r.ReadByte();
+			ID = r.ReadByte();
+			Name = FTXT.E.GetString(r.ReadBytes(8));
+			Address = r.ReadUInt16();
+			int size = r.ReadUInt16();
+			FileKind = (FileKindE)r.ReadByte();
+
+			if (r.ReadByte() != 4)
+				throw new InvalidOperationException("Bad Block Code");
+			Data = r.ReadBytes(size);
+		}
+
+		public void Write(BinaryWriter w)
+		{
+			w.Write((byte)3);
+			w.Write(Number);
+			w.Write(ID);
+			w.Write(FTXT.E.GetBytes(Name));
+			w.Write(Address);
+			w.Write((ushort)Data.Length);
+			w.Write((byte)FileKind);
+			w.Write((byte)4);
+			w.Write(Data);
+		}
+	}
+
+	public class FDSInspector
+	{
+	}
+}