nes mapper 177:

Shang Gu Shen Jian
Xing Zhan Qing Yuan
Wang Zi Fu Chou Ji
Xing He Zhan Shi
Mei Guo Fu Hao

BizHawk.Emulation/BizHawk.Emulation.csproj

@@ -173,6 +173,7 @@
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper164.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper168.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper176.cs" />
+    <Compile Include="Consoles\Nintendo\NES\Boards\Mapper177.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper178.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper180.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper193.cs" />

BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper177.cs

@@ -0,0 +1,49 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace BizHawk.Emulation.Consoles.Nintendo
+{
+	// china
+	// behavior from fceux
+	public class Mapper177 : NES.NESBoardBase
+	{
+		int prg;
+
+		public override bool Configure(NES.EDetectionOrigin origin)
+		{
+			switch (Cart.board_type)
+			{
+				case "MAPPER177":
+					break;
+				default:
+					return false;
+			}
+			AssertPrg(1024);
+			SetMirrorType(Cart.pad_h, Cart.pad_v);
+			return true;
+		}
+
+		public override void WritePRG(int addr, byte value)
+		{
+			prg = value & 0x1f;
+
+			if ((value & 0x20) != 0)
+				SetMirrorType(EMirrorType.Horizontal);
+			else
+				SetMirrorType(EMirrorType.Vertical);
+		}
+
+		public override byte ReadPRG(int addr)
+		{
+			return ROM[addr | prg << 15];
+		}
+
+		public override void SyncState(Serializer ser)
+		{
+			base.SyncState(ser);
+			ser.Sync("prg", ref prg);
+		}
+	}
+}