diff --git a/src/BizHawk.Emulation.Cores/Consoles/Sega/PicoDrive/LibPicoDrive.cs b/src/BizHawk.Emulation.Cores/Consoles/Sega/PicoDrive/LibPicoDrive.cs
index 0df8bae96d..ea07e055d9 100644
--- a/src/BizHawk.Emulation.Cores/Consoles/Sega/PicoDrive/LibPicoDrive.cs
+++ b/src/BizHawk.Emulation.Cores/Consoles/Sega/PicoDrive/LibPicoDrive.cs
@@ -29,7 +29,25 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.PicoDrive
 		/// <param name="_32xPreinit">If TRUE, preallocate 32X data structures.  When set to false,
 		///		32X games will still run, but will not have memory domains</param>
 		[BizImport(CC)]
-		public abstract bool Init(bool cd, bool _32xPreinit, Region regionAutoOrder,  Region regionOverride);
+		public abstract bool Init(bool cd, bool _32xPreinit, Region regionAutoOrder, Region regionOverride);
+
+		public const int CD_MAX_TRACKS = 100;
+
+		[StructLayout(LayoutKind.Sequential)]
+		public struct Track
+		{
+			public int start;
+			public int end;
+		}
+
+		[StructLayout(LayoutKind.Sequential)]
+		public class TOC
+		{
+			public int end;
+			public int last;
+			[MarshalAs(UnmanagedType.ByValArray, SizeConst = CD_MAX_TRACKS)]
+			public readonly Track[] tracks = new Track[CD_MAX_TRACKS];
+		}
 
 		[BizImport(CC)]
 		public abstract void SetCDReadCallback(CDReadCallback callback);
diff --git a/src/BizHawk.Emulation.Cores/Consoles/Sega/PicoDrive/PicoDrive.cs b/src/BizHawk.Emulation.Cores/Consoles/Sega/PicoDrive/PicoDrive.cs
index f6f79c05ad..fad2125799 100644
--- a/src/BizHawk.Emulation.Cores/Consoles/Sega/PicoDrive/PicoDrive.cs
+++ b/src/BizHawk.Emulation.Cores/Consoles/Sega/PicoDrive/PicoDrive.cs
@@ -71,7 +71,7 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.PicoDrive
 				_exe.AddReadonlyFile(comm.CoreFileProvider.GetFirmwareOrThrow(new("GEN", "CD_BIOS_EU")), "cd.eu");
 				_exe.AddReadonlyFile(comm.CoreFileProvider.GetFirmwareOrThrow(new("GEN", "CD_BIOS_US")), "cd.us");
 				_exe.AddReadonlyFile(comm.CoreFileProvider.GetFirmwareOrThrow(new("GEN", "CD_BIOS_JP")), "cd.jp");
-				_exe.AddReadonlyFile(gpgx.GPGX.GetCDData(cd), "toc");
+				_exe.AddReadonlyFile(GetTOC(cd), "toc");
 				_cd = cd;
 				_cdReader = new DiscSectorReader(_cd);
 				_core.SetCDReadCallback(_cdcallback);
@@ -154,6 +154,46 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.PicoDrive
 			return new LibPicoDrive.FrameInfo { Buttons = b };
 		}
 
+		private static byte[] GetTOC(Disc cd)
+		{
+			var toc = new LibPicoDrive.TOC();
+
+			var ses = cd.Session1;
+			var ntrack = ses.InformationTrackCount;
+
+			for (var i = 0; i < LibPicoDrive.CD_MAX_TRACKS; i++)
+			{
+				if (i < ntrack)
+				{
+					toc.tracks[i].start = ses.Tracks[i + 1].LBA;
+					toc.tracks[i].end = ses.Tracks[i + 2].LBA;
+					if (i == ntrack - 1)
+					{
+						toc.end = toc.tracks[i].end;
+						toc.last = ntrack;
+					}
+				}
+				else
+				{
+					toc.tracks[i].start = 0;
+					toc.tracks[i].end = 0;
+				}
+			}
+
+			var size = Marshal.SizeOf(toc);
+			var ret = new byte[size];
+
+			unsafe
+			{
+				fixed (byte* p = ret)
+				{
+					Marshal.StructureToPtr(ret, (IntPtr)p, false);
+				}
+			}
+
+			return ret;
+		}
+
 		private void CDRead(int lba, IntPtr dest, bool audio)
 		{
 			if (audio)
diff --git a/src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/GPGX.cs b/src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/GPGX.cs
index f6a5dfd511..3eff376ec3 100644
--- a/src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/GPGX.cs
+++ b/src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/GPGX.cs
@@ -304,17 +304,21 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.gpgx
 			var ret = new LibGPGX.CDData();
 
 			var ses = cd.Session1;
-			int ntrack = ses.InformationTrackCount;
+			var ntrack = ses.InformationTrackCount;
 
 			// bet you a dollar this is all wrong
-			//zero 07-jul-2015 - throws a dollar in the pile, since he probably messed it up worse
-			for (int i = 0; i < LibGPGX.CD_MAX_TRACKS; i++)
+			// zero 07-jul-2015 - throws a dollar in the pile, since he probably messed it up worse
+			for (var i = 0; i < LibGPGX.CD_MAX_TRACKS; i++)
 			{
+				ret.tracks[i].fd = IntPtr.Zero;
+				ret.tracks[i].loopEnabled = 0;
+				ret.tracks[i].loopOffset = 0;
+
 				if (i < ntrack)
 				{
-					ret.tracks[i].mode = ses.Tracks[i].Mode;
 					ret.tracks[i].start = ses.Tracks[i + 1].LBA;
 					ret.tracks[i].end = ses.Tracks[i + 2].LBA;
+					ret.tracks[i].mode = ses.Tracks[i].Mode;
 					if (i == ntrack - 1)
 					{
 						ret.end = ret.tracks[i].end;
@@ -323,25 +327,27 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.gpgx
 				}
 				else
 				{
-					ret.tracks[i].mode = 0;
 					ret.tracks[i].start = 0;
 					ret.tracks[i].end = 0;
+					ret.tracks[i].mode = 0;
 				}
 			}
 
+			ret.sub = IntPtr.Zero;
 			return ret;
 		}
 
 		public static unsafe byte[] GetCDData(Disc cd)
 		{
 			var ret = GetCDDataStruct(cd);
-			int size = Marshal.SizeOf(ret);
-			byte[] retdata = new byte[size];
+			var size = Marshal.SizeOf(ret);
+			var retdata = new byte[size];
 
-			fixed (byte* p = &retdata[0])
+			fixed (byte* p = retdata)
 			{
 				Marshal.StructureToPtr(ret, (IntPtr)p, false);
 			}
+
 			return retdata;
 		}
 
diff --git a/src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/LibGPGX.cs b/src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/LibGPGX.cs
index aa355da0eb..cd8f12744f 100644
--- a/src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/LibGPGX.cs
+++ b/src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/LibGPGX.cs
@@ -282,9 +282,12 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.gpgx
 		[StructLayout(LayoutKind.Sequential)]
 		public struct CDTrack
 		{
+			public IntPtr fd;
 			public int start;
 			public int end;
 			public int mode;
+			public int loopEnabled;
+			public int loopOffset;
 		}
 
 		[StructLayout(LayoutKind.Sequential)]
@@ -294,6 +297,7 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.gpgx
 			public int last;
 			[MarshalAs(UnmanagedType.ByValArray, SizeConst = CD_MAX_TRACKS)]
 			public readonly CDTrack[] tracks = new CDTrack[CD_MAX_TRACKS];
+			public IntPtr sub;
 		}
 
 		[BizImport(CallingConvention.Cdecl)]