diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/MMC3_family/TLSROM.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/MMC3_family/TLSROM.cs
index ffea03e63c..0fe238bfeb 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/MMC3_family/TLSROM.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/MMC3_family/TLSROM.cs
@@ -1,9 +1,15 @@
+using System;
+using BizHawk.Common;
+using BizHawk.Common.NumberExtensions;
+
 namespace BizHawk.Emulation.Cores.Nintendo.NES
 {
 	//aka mapper 118
 	//wires the mapper outputs to control the nametables
 	public sealed class TLSROM : MMC3Board_Base
 	{
+		public int[] nametables = new int[4];
+
 		public override bool Configure(NES.EDetectionOrigin origin)
 		{
 			//analyze board type
@@ -20,8 +26,8 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 					AssertBattery(true);
 					break;
 				case "TENGEN-800037": //Alien Syndrome (U)
-					// this board is actually a RAMBO-1 (mapper064) with TLS-style rewiring
-					// but it seems to work fine here, so lets not worry about it
+									  // this board is actually a RAMBO-1 (mapper064) with TLS-style rewiring
+									  // but it seems to work fine here, so lets not worry about it
 					AssertPrg(128); AssertChr(128); AssertVram(0); AssertWram(0);
 					break;
 				case "MAPPER158":
@@ -38,24 +44,86 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 			BaseSetup();
 			SetMirrorType(EMirrorType.Vertical);
 
+			//maybe need other initialization
+			nametables[0] = 0;
+			nametables[1] = 1;
+			nametables[2] = 0;
+			nametables[3] = 1;
+
 			return true;
 		}
 
 		public override void WritePRG(int addr, byte value)
 		{
-			base.WritePRG(addr, value);
+			int nt = value >> 7;
+
+			if ((addr & 0x6001) == 0x1)
+			{
+				if (!mmc3.chr_mode)
+				{
+					switch (mmc3.reg_addr)
+					{
+						case 0:
+							nametables[0] = nt;
+							nametables[1] = nt;
+							break;
+						case 1:
+							nametables[2] = nt;
+							nametables[3] = nt;
+							break;
+					}
+				}
+				else
+				{
+					switch (mmc3.reg_addr)
+					{
+						case 2:
+							nametables[0] = nt;
+							break;
+						case 3:
+							nametables[1] = nt;
+							break;
+						case 4:
+							nametables[2] = nt;
+							break;
+						case 5:
+							nametables[3] = nt;
+							break;
+					}
+				}
+			}
+
+			if ((addr & 0x6001) != 0x2000)
+				base.WritePRG(addr, value);
 		}
 
 		public override byte ReadPPU(int addr)
 		{
 			if (addr < 0x2000) return base.ReadPPU(addr);
-			else return base.ReadPPU(RewireNametable_TLSROM(addr, 7));
+			else
+			{
+				int nt = ((addr - 0x2000) >> 10) & 0x3;
+				addr = 0x2000 + (addr & 0x3FF) + (nametables[nt] << 10);
+				return base.ReadPPU(addr);
+
+			}
 		}
 		public override void WritePPU(int addr, byte value)
 		{
 			if (addr < 0x2000) base.WritePPU(addr, value);
-			else base.WritePPU(RewireNametable_TLSROM(addr, 7), value);
+			else
+			{
+				int nt = ((addr - 0x2000) >> 10) & 0x3;
+				addr = 0x2000 + (addr & 0x3FF) + (nametables[nt] << 10);
+				base.WritePPU(addr, value);
+			}
+
 		}
 
+		public override void SyncState(Serializer ser)
+		{
+			base.SyncState(ser);
+			ser.Sync("nametables", ref nametables, false);
+		}
 	}
 }
\ No newline at end of file