diff --git a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
index 0eddeaf9a3..9eb5ad059a 100644
--- a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
+++ b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
@@ -626,6 +626,7 @@
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper177.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper178.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper180.cs" />
+    <Compile Include="Consoles\Nintendo\NES\Boards\Mapper186.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper188.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper193.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper200.cs" />
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper186.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper186.cs
new file mode 100644
index 0000000000..7bc16513cc
--- /dev/null
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper186.cs
@@ -0,0 +1,78 @@
+using BizHawk.Common;
+
+namespace BizHawk.Emulation.Cores.Nintendo.NES
+{
+	public class Mapper186 : NES.NESBoardBase
+	{
+		private ByteBuffer _SRAM = new ByteBuffer(3072);
+		private ByteBuffer regs = new ByteBuffer(4);
+
+		public override bool Configure(NES.EDetectionOrigin origin)
+		{
+			switch (Cart.board_type)
+			{
+				case "MAPPER186":
+					break;
+				default:
+					return false;
+			}
+
+			return true;
+		}
+
+		public override byte ReadPRG(int addr)
+		{
+			if (addr < 0x4000)
+			{
+				return ROM[(regs[1] << 14) + (addr & 0x3FFF)];
+			}
+
+			// C000-FFFF is always bank 0
+			return ROM[addr & 0x3FFF];
+		}
+
+		public override byte ReadWRAM(int addr)
+		{
+			return ROM[(regs[0] >> 6) + addr];
+		}
+
+		public override void WriteEXP(int addr, byte value)
+		{
+			if (addr >= 0x200 && addr < 0x400)
+			{
+				if (((addr + 0x4000) & 0x4203) > 0)
+				{
+					regs[addr & 3] = value;
+				}
+			}
+			else if (addr < 0x1000)
+			{
+				_SRAM[addr - 0x400] = value;
+			}
+			else
+			{
+				base.WriteEXP(addr, value);
+			}
+		}
+
+		public override byte ReadEXP(int addr)
+		{
+			if (addr >= 0x200 && addr < 0x400)
+			{
+				switch (addr + 0x4000)
+				{
+					case 0x4200: return 0x00;
+					case 0x4201: return 0x00;
+					case 0x4202: return 0x40;
+					case 0x4203: return 0x00;
+				}
+			}
+			else if (addr < 0x1000)
+			{
+				return _SRAM[addr - 0x400];
+			}
+
+			return base.ReadEXP(addr);
+		}
+	}
+}