diff --git a/BizHawk.Emulation/BizHawk.Emulation.csproj b/BizHawk.Emulation/BizHawk.Emulation.csproj
index 44817851d3..27582fe851 100644
--- a/BizHawk.Emulation/BizHawk.Emulation.csproj
+++ b/BizHawk.Emulation/BizHawk.Emulation.csproj
@@ -234,6 +234,7 @@
       <SubType>Code</SubType>
     </Compile>
     <Compile Include="Consoles\Nintendo\NES\Boards\PxROM_FxROM.cs" />
+    <Compile Include="Consoles\Nintendo\NES\Boards\SachenSimple.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Sunsoft1.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Sunsoft2_m89.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Sunsoft2_m93.cs" />
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/SachenSimple.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/SachenSimple.cs
new file mode 100644
index 0000000000..95a799d162
--- /dev/null
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/SachenSimple.cs
@@ -0,0 +1,110 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace BizHawk.Emulation.Consoles.Nintendo
+{
+	// a number of boards used by Sachen (and others?)
+	// 32K prgrom blocks and 8k chrrom blocks
+	// behavior gleamed from FCEUX
+	// "Qi Wang - Chinese Chess (MGC-001) (Ch) [!]" and "Twin Eagle (Sachen) [!]" seem to have problems
+	public class SachenSimple : NES.NESBoardBase
+	{
+		Action<byte> ExpWrite = null;
+		Action<byte> PrgWrite = null;
+
+		int prg = 0;
+		int chr = 0;
+		int prg_mask;
+		int chr_mask;
+		int prg_addr_mask; // some carts have 16KB prg unswappable
+
+		public override bool Configure(NES.EDetectionOrigin origin)
+		{
+			switch (Cart.board_type)
+			{
+				case "MAPPER146":
+				case "UNL-SA-016-1M":
+					ExpWrite = SA0161M_Write;
+					break;
+				case "MAPPER145":
+					ExpWrite = SA72007_Write;
+					break;
+				case "MAPPER133":
+					ExpWrite = SA72008_Write;
+					break;
+				case "MAPPER160":
+					ExpWrite = SA009_Write;
+					break;
+				case "MAPPER149":
+					PrgWrite = SA72007_Write;
+					break;
+				case "MAPPER148":
+					PrgWrite = SA0161M_Write;
+					break;
+				default:
+					return false;
+			}
+			AssertPrg(16, 32, 64);
+			AssertChr(8, 16, 32, 64);
+			AssertVram(0);
+			AssertWram(0);
+			prg_mask = Cart.prg_size / 32 - 1;
+			chr_mask = Cart.chr_size / 8 - 1;
+			prg_addr_mask = Cart.prg_size * 1024 - 1;
+			SetMirrorType(Cart.pad_h, Cart.pad_v);
+			return true;
+		}
+
+		void SA0161M_Write(byte value)
+		{
+			prg = (value >> 3) & 1 & prg_mask;
+			chr = value & 7 & chr_mask;
+		}
+		void SA72007_Write(byte value)
+		{
+			chr = (value >> 7) & 1 & chr_mask;
+		}
+		void SA009_Write(byte value)
+		{
+			chr = value & 1 & chr_mask;
+		}
+		void SA72008_Write(byte value)
+		{
+			prg = (value >> 2) & 1 & prg_mask;
+			chr = value & 3 & chr_mask;
+		}
+
+		public override void WriteEXP(int addr, byte value)
+		{
+			if (ExpWrite != null && (addr & 0x100) != 0)
+				ExpWrite(value);
+		}
+
+		public override void WritePRG(int addr, byte value)
+		{
+			if (PrgWrite != null)
+				PrgWrite(value);
+		}
+
+		public override byte ReadPRG(int addr)
+		{
+			return ROM[(addr & prg_addr_mask) + (prg << 15)];
+		}
+		public override byte ReadPPU(int addr)
+		{
+			if (addr < 0x2000)
+				return VROM[addr + (chr << 13)];
+			else
+				return base.ReadPPU(addr);
+		}
+
+		public override void SyncState(Serializer ser)
+		{
+			base.SyncState(ser);
+			ser.Sync("chr", ref chr);
+			ser.Sync("prg", ref prg);
+		}
+	}
+}