diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/FDS/FDS.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/FDS/FDS.cs
index d9b84a5947..c397dccb03 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/FDS/FDS.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/FDS/FDS.cs
@@ -92,6 +92,21 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 		/// <param name="diskimage"></param>
 		public void SetDiskImage(byte[] diskimage)
 		{
+			// each FDS format is worse than the last
+			if (diskimage.Take(4).SequenceEqual(System.Text.Encoding.ASCII.GetBytes("\x01*NI")))
+			{
+				int nsides = diskimage.Length / 65500;
+
+				MemoryStream ms = new MemoryStream();
+				ms.Write(System.Text.Encoding.ASCII.GetBytes("FDS\x1A"), 0, 4);
+				ms.WriteByte((byte)nsides);
+				byte[] nulls = new byte[11];
+				ms.Write(nulls, 0, 11);
+				ms.Write(diskimage, 0, diskimage.Length);
+				ms.Close();
+				diskimage = ms.ToArray();
+			}
+			
 			this.diskimage = diskimage;
 			diskdiffs = new byte[NumSides][];
 		}
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/NES.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/NES.cs
index 478b963af8..9ae4b580ca 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/NES.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/NES.cs
@@ -590,7 +590,8 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 				hash_sha1_several.Add(hash_sha1);
 				LoadWriteLine("headerless rom hash: {0}", hash_sha1);
 			}
-			else if (file.Take(4).SequenceEqual(System.Text.Encoding.ASCII.GetBytes("FDS\x1A")))
+			else if (file.Take(4).SequenceEqual(System.Text.Encoding.ASCII.GetBytes("FDS\x1A"))
+				|| file.Take(4).SequenceEqual(System.Text.Encoding.ASCII.GetBytes("\x01*NI")))
 			{
 				// there's not much else to do with FDS images other than to feed them to the board
 				origin = EDetectionOrigin.FDS;