diff --git a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
index 1223bcc205..72bbd8db22 100644
--- a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
+++ b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
@@ -649,6 +649,7 @@
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper231.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper233.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper235.cs" />
+    <Compile Include="Consoles\Nintendo\NES\Boards\Mapper236.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper240.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper241.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper242.cs" />
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper236.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper236.cs
new file mode 100644
index 0000000000..75aba05481
--- /dev/null
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper236.cs
@@ -0,0 +1,116 @@
+using System;
+using BizHawk.Common;
+
+namespace BizHawk.Emulation.Cores.Nintendo.NES
+{
+	public sealed class Mapper236 : NES.NESBoardBase
+	{
+		[MapperProp]
+		public byte CartSwitch_70in1 = 0xd;
+
+		[MapperProp]
+		public byte CartSwitch_800in1 = 06;
+
+		private bool isLargeBanks = false;
+		private byte large_bank;
+		private byte prg_bank;
+		private byte chr_bank;
+		private byte bank_mode;
+
+		public override bool Configure(NES.EDetectionOrigin origin)
+		{
+			switch (Cart.board_type)
+			{
+				//case "MAPPER236": // Nestopia classifies both boards as MAPPER236, but I have yet to a see a ROM iwth this iNES header, and how would we determine which one it was?
+				case "UNIF_BMC-70in1":
+					isLargeBanks = false;
+					break;
+				case "UNIF_BMC-70in1B":
+					isLargeBanks = true;
+					break;
+				default:
+					return false;
+			}
+
+			AutoMapperProps.Apply(this);
+
+			return true;
+		}
+
+		public override void SyncState(Serializer ser)
+		{
+			base.SyncState(ser);
+			ser.Sync("isLargeBanks", ref isLargeBanks);
+			ser.Sync("large_bank", ref large_bank);
+			ser.Sync("prg_bank", ref prg_bank);
+			ser.Sync("chr_bank", ref chr_bank);
+			ser.Sync("bank_mode", ref bank_mode);
+			ser.Sync("Cart_Switch", ref CartSwitch_70in1);
+			ser.Sync("Cart_Switch", ref CartSwitch_800in1);
+		}
+
+		public override void WritePRG(int addr, byte value)
+		{
+			addr += 0x8000;
+			if ((addr & 0x4000) > 0)
+			{
+				bank_mode = (byte)(addr & 0x30);
+				prg_bank = (byte)(addr & 7);
+			}
+			else
+			{
+				var mirroring = ((addr & 0x20) >> 5) ^ 1;
+				SetMirrorType(mirroring > 0 ? EMirrorType.Vertical : EMirrorType.Horizontal);
+
+				if (isLargeBanks)
+				{
+					large_bank = (byte)((addr & 3) << 3);
+				}
+				else
+				{
+					chr_bank = (byte)(addr & 7);
+				}
+			}
+		}
+
+		public override byte ReadPRG(int addr)
+		{
+			switch (bank_mode)
+			{
+				default:
+					throw new InvalidOperationException("Unexpected bank_mode value");
+				case 0x00:
+				case 0x10:
+					int bank;
+					if (addr < 0x4000)
+					{
+						bank = (large_bank | prg_bank);
+					}
+					else
+					{
+						bank = (large_bank | 7);
+					}
+
+					if (bank_mode == 0x10)
+					{
+						addr = (addr & 0x7FF0) | ((isLargeBanks ? CartSwitch_800in1 : CartSwitch_70in1) & 0xf);
+					}
+					return ROM[(bank << 14) + (addr & 0x3FFF)];
+				case 0x20:
+					return ROM[(((large_bank | prg_bank) >> 1) << 15) + addr];
+				case 0x30:
+					return ROM[((large_bank | prg_bank) << 14) + (addr & 0x3FFF)];
+			}
+		}
+
+		public override byte ReadPPU(int addr)
+		{
+			if (addr < 0x2000 && VROM != null)
+			{
+				return VROM[(chr_bank << 13) + (addr & 0x1FFF)];
+			}
+
+			return base.ReadPPU(addr);
+		}
+	}
+}