diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/BoardSystem.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/BoardSystem.cs
index 1ce50b7f86..b415591fb8 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/BoardSystem.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/BoardSystem.cs
@@ -83,6 +83,23 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 				mirroring[3] = d;
 			}
 
+			protected void ApplyMemoryMapMask(int mask, ByteBuffer map)
+			{
+				byte bmask = (byte)mask;
+				for (int i = 0; i < map.len; i++)
+					map[i] &= bmask;
+			}
+
+			//make sure you have bank-masked the map 
+			protected int ApplyMemoryMap(int blockSizeBits, ByteBuffer map, int addr)
+			{
+				int bank = addr >> blockSizeBits;
+				int ofs = addr & ((1 << blockSizeBits) - 1);
+				bank = map[bank];
+				addr = (bank << blockSizeBits) | ofs;
+				return addr;
+			}
+
 			public static EMirrorType CalculateMirrorType(int pad_h, int pad_v)
 			{
 				if (pad_h == 0)
@@ -168,6 +185,18 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			public virtual void AddressPPU(int addr) { }
 			public virtual byte PeekPPU(int addr) { return ReadPPU(addr); }
 
+			/// <summary>
+			/// reads PPU from a pattern table address. asserts addr lt 0x2000
+			/// This is just so that we can accelerate things a tiny bit by not checking against 0x2000 excessively
+			/// </summary>
+			protected virtual byte ReadPPUChr(int addr)
+			{
+				Debug.Assert(addr < 0x2000);
+				if (VROM != null)
+					return VROM[addr];
+				else return VRAM[addr];
+			}
+
 			public virtual byte ReadPPU(int addr)
 			{
 				if (addr < 0x2000)
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper164.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper164.cs
index b4d29edc13..c474459a24 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper164.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper164.cs
@@ -10,6 +10,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 		//Mapper 164
 		//Final Fantasy V (Unl)
 
+		//state
 		int prg;
 
 		public override bool Configure(NES.EDetectionOrigin origin)
@@ -44,5 +45,11 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 		{
 			return VROM[addr + (prg * 0x8000)];
 		}
+
+		public override void SyncState(Serializer ser)
+		{
+			base.SyncState(ser);
+			ser.Sync("prg", ref prg);
+		}
 	}
 }
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper176.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper176.cs
new file mode 100644
index 0000000000..e0bdb3d1cb
--- /dev/null
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper176.cs
@@ -0,0 +1,124 @@
+using System;
+using System.IO;
+using System.Diagnostics;
+
+namespace BizHawk.Emulation.Consoles.Nintendo
+{
+	class Mapper176 : NES.NESBoardBase
+	{
+		//configuration
+		int prg_bank_mask_8k, chr_bank_mask_8k;
+
+		//state
+		int mirror;
+		ByteBuffer prg_banks_8k = new ByteBuffer(4);
+		ByteBuffer chr_banks_8k = new ByteBuffer(1);
+		Bit sbw;
+
+		public override bool Configure(NES.EDetectionOrigin origin)
+		{
+			//configure
+			switch (Cart.board_type)
+			{
+				case "MAPPER176":
+					break;
+				default:
+					return false;
+			}
+			prg_bank_mask_8k = (Cart.prg_size / 8) - 1;
+			chr_bank_mask_8k = (Cart.chr_size / 8) - 1;
+
+			mirror = 0;
+			SyncMirror();
+
+			sbw = 0;
+			prg_banks_8k[0] = 0;
+			prg_banks_8k[1] = 1;
+			prg_banks_8k[2] = 62;
+			prg_banks_8k[3] = 63;
+			ApplyMemoryMapMask(prg_bank_mask_8k,prg_banks_8k);
+
+			chr_banks_8k[0] = 0;
+			ApplyMemoryMapMask(chr_bank_mask_8k, chr_banks_8k);
+
+			return true;
+		}
+
+		static readonly EMirrorType[] kMirrorTypes = {EMirrorType.Vertical,EMirrorType.Horizontal,EMirrorType.OneScreenA,EMirrorType.OneScreenB};
+		void SyncMirror()
+		{
+			SetMirrorType(kMirrorTypes[mirror]);
+		}
+
+		public override byte ReadPRG(int addr)
+		{
+			addr = ApplyMemoryMap(13,prg_banks_8k,addr);
+			return ROM[addr];
+		}
+
+		public override void WritePRG(int addr, byte value)
+		{
+			switch (addr)
+			{
+				case 0x2000: //0xA000
+					mirror = value & 3;
+					SyncMirror();
+					break;
+				case 0x2001: //0xA001
+					//we_sram = data & 0x03;
+					break;
+			}
+		}
+
+		public override byte ReadPPU(int addr)
+		{
+			if (addr < 0x2000)
+			{
+				addr = ApplyMemoryMap(13, chr_banks_8k, addr);
+				return base.ReadPPUChr(addr);
+			}
+			else return base.ReadPPU(addr);
+		}
+
+		void SetPrg32k(int value)
+		{
+			for(int i=0;i<4;i++)
+				prg_banks_8k[i] = (byte)(value * 4 + i);
+			ApplyMemoryMapMask(prg_bank_mask_8k, prg_banks_8k);
+		}
+
+		public override void WriteEXP(int addr, byte value)
+		{
+			switch (addr)
+			{
+				case 0x1000: //0x5000
+					break;
+				case 0x1001: //0x5001
+					if (sbw) SetPrg32k(value);
+					break;
+				case 0x1010: //0x5010
+					if (value == 0x24) sbw = 1;
+					break;
+				case 0x1011: //0x5011
+					if (sbw) SetPrg32k(value >> 1);
+					break;
+				case 0x1FF1: //0x5FF1
+					SetPrg32k(value>>1);
+					break;
+				case 0x1FF2: //0x5FF2
+					chr_banks_8k[0] = (byte)value;
+					ApplyMemoryMapMask(chr_bank_mask_8k, chr_banks_8k);
+					break;
+			}
+		}
+
+		public override void SyncState(Serializer ser)
+		{
+			base.SyncState(ser);
+			ser.Sync("mirror", ref mirror);
+			ser.Sync("prg_banks_8k", ref prg_banks_8k);
+			ser.Sync("chr_banks_8k", ref chr_banks_8k);
+			ser.Sync("sbw", ref sbw);
+		}
+	}
+}