diff --git a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
index 7d73dd6f08..596628c160 100644
--- a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
+++ b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
@@ -242,6 +242,7 @@
     <Compile Include="Consoles\Nintendo\NES\Boards\BANDAI_74_161_161_32.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\BxROM.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Camerica.cs" />
+    <Compile Include="Consoles\Nintendo\NES\Boards\FS304.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper028.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\CNROM.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\CPROM.cs">
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/FS304.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/FS304.cs
new file mode 100644
index 0000000000..101c1c0307
--- /dev/null
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/FS304.cs
@@ -0,0 +1,60 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace BizHawk.Emulation.Cores.Nintendo.NES
+{
+	public class FS304 : NES.NESBoardBase
+	{
+		// waixing?
+
+		int prg;
+		int prg_mask_32k;
+
+		public override bool Configure(NES.EDetectionOrigin origin)
+		{
+			switch (Cart.board_type)
+			{
+				case "UNIF_UNL-FS304":
+					AssertChr(0);
+					AssertPrg(512, 1024, 2048, 4096);
+					Cart.vram_size = 8;
+					Cart.wram_size = 8;
+					Cart.wram_battery = true;
+					break;
+				default:
+					return false;
+			}
+
+			prg_mask_32k = Cart.prg_size / 32 - 1;
+			SetMirrorType(Cart.pad_h, Cart.pad_v);
+			return true;
+		}
+
+		public override void WriteEXP(int addr, byte value)
+		{
+			switch (addr & 0x1300)
+			{
+				case 0x1000:
+					prg &= ~0x0e;
+					prg |= value & 0x0e;
+					break;
+				case 0x1100:
+					prg &= ~0x01;
+					prg |= value >> 1 & 0x01;
+					break;
+				case 0x1200:
+					prg &= ~0xf0;
+					prg |= value << 4 & 0xf0;
+					break;
+			}
+			prg &= prg_mask_32k;
+		}
+
+		public override byte ReadPRG(int addr)
+		{
+			return ROM[addr | prg << 15];
+		}
+	}
+}
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Unif.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Unif.cs
index 2b01cd03d3..8b04ed13a0 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Unif.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Unif.cs
@@ -98,6 +98,10 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 				byte[] all = ms.ToArray();
 				ci.sha1 = "sha1:" + Util.Hash_SHA1(all, 0, all.Length);
 			}
+
+			// other code will expect this
+			if (chrrom.Length == 0)
+				chrrom = null;
 		}
 
 		public NES.CartInfo GetCartInfo() { return ci; }