diff --git a/BizHawk.Emulation/BizHawk.Emulation.csproj b/BizHawk.Emulation/BizHawk.Emulation.csproj
index 3e8c968468..514c7c5c64 100644
--- a/BizHawk.Emulation/BizHawk.Emulation.csproj
+++ b/BizHawk.Emulation/BizHawk.Emulation.csproj
@@ -148,6 +148,7 @@
     <Compile Include="Consoles\Nintendo\NES\Boards\JALECO_JF_17.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\JALECO_JF_19.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper015.cs" />
+    <Compile Include="Consoles\Nintendo\NES\Boards\Mapper057.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper058.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper069.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper107.cs" />
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper057.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper057.cs
new file mode 100644
index 0000000000..8281d9e792
--- /dev/null
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper057.cs
@@ -0,0 +1,127 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace BizHawk.Emulation.Consoles.Nintendo
+{
+	class Mapper057 : NES.NESBoardBase
+	{
+		/*
+		Here are Disch's original notes:  
+		========================
+		=  Mapper 057          =
+		========================
+
+		Example Games:
+		--------------------------
+		GK 47-in-1
+		6-in-1 (SuperGK)
+
+
+		Registers:
+		---------------------------
+
+		Range,Mask:   $8000-FFFF, $8800
+
+		$8000:  [.H.. .AAA]
+		H = High bit of CHR reg (bit 4)
+		A = Low 3 bits of CHR Reg (OR with 'B' bits)
+
+		$8800:  [PPPO MBBB]
+		P = PRG Reg
+		O = PRG Mode
+		M = Mirroring (0=Vert, 1=Horz)
+		B = Low 3 bits of CHR Reg (OR with 'A' bits)
+
+
+		CHR Setup:
+		---------------------------
+		'A' and 'B' bits combine with an OR to get the low 3 bits of the desired page, and the 'H' bit is the high
+		bit.  This 4-bit value selects an 8k page @ $0000
+
+
+		PRG Setup:
+		---------------------------
+
+					  $8000   $A000   $C000   $E000  
+					+---------------+---------------+
+		PRG Mode 0: |     $8800     |     $8800     |
+					+-------------------------------+
+		PRG Mode 1: |            <$8800>            |
+					+-------------------------------+
+		*/
+
+		bool prg_mode = false;
+		int chr_reg;
+		int prg_reg;
+
+		public override bool Configure(NES.EDetectionOrigin origin)
+		{
+			switch (Cart.board_type)
+			{
+				case "MAPPER057":
+					break;
+				default:
+					return false;
+			}
+
+			SetMirrorType(EMirrorType.Horizontal);
+
+			return true;
+		}
+
+		public override void SyncState(Serializer ser)
+		{
+			ser.Sync("prg_reg", ref prg_reg);
+			ser.Sync("chr_reg", ref chr_reg);
+			ser.Sync("prg_mode", ref prg_mode);
+			base.SyncState(ser);
+		}
+
+		public override void WritePRG(int addr, byte value)
+		{
+			if (addr == 0)
+			{
+				chr_reg = (value & 0x07) | ((value & 0x40) >> 3);
+			}
+			else if ((addr & 0x800) > 0)
+			{
+				prg_reg = (value >> 5) & 0x07;
+				prg_mode = value.Bit(4);
+				chr_reg |= (value & 0x07);
+				if (addr.Bit(3))
+				{
+					SetMirrorType(EMirrorType.Horizontal);
+				}
+				else
+				{
+					SetMirrorType(EMirrorType.Vertical);
+				}
+			}
+
+			//Console.WriteLine("chr page = {0}", chr_reg);
+		}
+
+		public override byte ReadPRG(int addr)
+		{
+			if (prg_mode)
+			{
+				return ROM[((prg_reg >> 1) * 0x8000) + addr];
+			}
+			else
+			{
+				return ROM[(prg_reg * 0x4000) + (addr & 0x3FFF)];
+			}
+		}
+
+		public override byte ReadPPU(int addr)
+		{
+			if (addr < 0x2000)
+			{
+				return VROM[(chr_reg * 0x2000) + addr];
+			}
+			return base.ReadPPU(addr);
+		}
+	}
+}