diff --git a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
index 4a00050be4..5a536eb916 100644
--- a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
+++ b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
@@ -664,6 +664,7 @@
     <Compile Include="Consoles\Nintendo\NES\Boards\BxROM.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Camerica.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\CamericaGoldenFive.cs" />
+    <Compile Include="Consoles\Nintendo\NES\Boards\Mapper043.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Cony.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\CoolBoy.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\DatachBarcode.cs" />
@@ -859,6 +860,7 @@
     <Compile Include="Consoles\Nintendo\NES\Boards\Taito_X1_017.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\TENGEN-800032.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\TENGEN_800008.cs" />
+    <Compile Include="Consoles\Nintendo\NES\Boards\UNIF\UNIF_UNL_SMB2J.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\UNIF\UNIF-DREAMTECH01.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\UNIF\UNIF_BMC-12-IN-1.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\UNIF\UNIF_BMC-190in1.cs" />
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper043.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper043.cs
new file mode 100644
index 0000000000..49e87f21da
--- /dev/null
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper043.cs
@@ -0,0 +1,138 @@
+using System;
+using BizHawk.Common;
+
+namespace BizHawk.Emulation.Cores.Nintendo.NES
+{
+	public sealed class Mapper043 : NES.NESBoardBase
+	{
+		int prg = 0;
+		int irqcnt = 0;
+		bool irqenable = false;
+		bool swap;
+
+
+		private static int[] lut = { 4, 3, 5, 3, 6, 3, 7, 3 };
+
+		public override bool Configure(NES.EDetectionOrigin origin)
+		{
+			switch (Cart.board_type)
+			{
+				case "MAPPER043":
+					break;
+				default:
+					return false;
+			}
+
+			Cart.wram_size = 0;
+			// not sure on initial mirroring
+			SetMirrorType(EMirrorType.Vertical);
+			return true;
+		}
+
+		public override void WriteEXP(int addr, byte value)
+		{
+			addr += 0x4000;
+
+			switch (addr & 0xF1FF)
+			{
+				case 0x4022:
+					prg = lut[value & 0x7];
+					break;
+
+				case 0x4120:
+					swap = (value & 1) == 1;
+					break;
+
+				case 0x4122:
+					irqenable = (value & 1) == 1;
+					IRQSignal = false;
+					irqcnt = 0;
+					break;
+			}
+		}
+
+		public override void WritePRG(int addr, byte value)
+		{
+			addr += 0x8000;
+			switch (addr & 0xF1FF)
+			{
+				case 0x8122:
+					irqenable = (value & 1) == 1;
+					IRQSignal = false;
+					irqcnt = 0;
+					break;
+			}
+		}
+
+		public override byte ReadEXP(int addr)
+		{
+			if (addr > 0x1000)
+			{
+				return ROM[(addr - 0x1000) + 8 * 0x2000];
+			}
+			else return base.ReadEXP(addr);
+		}
+
+		public override byte ReadWRAM(int addr)
+		{
+			if (swap)
+			{
+				return ROM[addr];
+			}
+			else
+			{
+				return ROM[addr + 0x4000];
+			}
+		}
+
+		public override byte ReadPRG(int addr)
+		{
+			if (addr < 0x2000)
+			{
+				return ROM[addr + 0x2000];
+			}
+			else if (addr < 0x4000)
+			{
+				return ROM[addr - 0x2000];
+			}
+			else if (addr < 0x6000)
+			{
+				return ROM[(addr - 0x4000) + prg * 0x2000];
+			}
+			else
+			{
+				if (swap)
+				{
+					return ROM[(addr - 0x6000) + 8 * 0x2000];
+				}
+				else
+				{
+					return ROM[(addr - 0x6000) + 9 * 0x2000];
+				}
+			}
+		}
+
+		public override void ClockCPU()
+		{
+			if (irqenable)
+			{
+				irqcnt++;
+
+				if (irqcnt >= 4096)
+				{
+					irqenable = false;
+					IRQSignal = true;
+				}				
+			}
+		}
+
+		public override void SyncState(Serializer ser)
+		{
+			base.SyncState(ser);
+			ser.Sync("prg", ref prg);
+			ser.Sync("irqenable", ref irqenable);
+			ser.Sync("irqcnt", ref irqcnt);
+			ser.Sync("swap", ref swap);
+		}
+	}
+}
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/UNIF/UNIF_UNL_SMB2J.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/UNIF/UNIF_UNL_SMB2J.cs
new file mode 100644
index 0000000000..41123272c6
--- /dev/null
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/UNIF/UNIF_UNL_SMB2J.cs
@@ -0,0 +1,92 @@
+using System;
+using BizHawk.Common;
+
+namespace BizHawk.Emulation.Cores.Nintendo.NES
+{
+	public sealed class UNIF_UNL_SMB2J : NES.NESBoardBase
+	{
+		int prg = 0;
+		int prg_count;
+		int irqcnt = 0;
+		bool irqenable = false;
+		bool swap;
+
+		public override bool Configure(NES.EDetectionOrigin origin)
+		{
+			switch (Cart.board_type)
+			{
+				case "UNIF_UNL-SMB2J":
+					break;
+				default:
+					return false;
+			}
+
+			prg_count = Cart.prg_size/4;
+
+			Cart.wram_size = 0;
+			// not sure on initial mirroring
+			SetMirrorType(EMirrorType.Vertical);
+			return true;
+		}
+
+		public override void WriteEXP(int addr, byte value)
+		{
+			addr += 0x4000;
+
+			switch (addr)
+			{
+				case 0x4022:
+					if (ROM.Length > 0x10000) { prg = (value & 0x01) << 2; }					
+					break;
+
+				case 0x4122:
+					irqenable = (value & 3) > 0;
+					IRQSignal = false;
+					irqcnt = 0;
+					break;
+			}
+		}
+
+		public override byte ReadEXP(int addr)
+		{
+			if (addr > 0x1000)
+			{
+				return ROM[(addr - 0x1000) + (prg_count - 3) * 0x1000];
+			}
+			else return base.ReadEXP(addr);
+		}
+
+		public override byte ReadWRAM(int addr)
+		{
+			return ROM[addr + (prg_count - 2) * 0x1000];
+		}
+
+		public override byte ReadPRG(int addr)
+		{
+			return ROM[(addr + prg * 01000)];
+		}
+
+		public override void ClockCPU()
+		{
+			if (irqenable)
+			{
+				irqcnt++;
+
+				if (irqcnt >= 4096)
+				{
+					irqenable = false;
+					IRQSignal = true;
+				}				
+			}
+		}
+
+		public override void SyncState(Serializer ser)
+		{
+			base.SyncState(ser);
+			ser.Sync("prg", ref prg);
+			ser.Sync("irqenable", ref irqenable);
+			ser.Sync("irqcnt", ref irqcnt);
+			ser.Sync("swap", ref swap);
+		}
+	}
+}