From 48766c2b88af8115cfe67757a39a1c2b0fed4246 Mon Sep 17 00:00:00 2001
From: adelikat <adelikat@tasvideos.org>
Date: Fri, 28 Oct 2016 18:11:34 -0500
Subject: [PATCH] NesHawk - support mapper 170

---
 .../BizHawk.Emulation.Cores.csproj            |  1 +
 .../Consoles/Nintendo/NES/Boards/Mapper170.cs | 60 +++++++++++++++++++
 2 files changed, 61 insertions(+)
 create mode 100644 BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper170.cs

diff --git a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
index 92a232e83c..2661109f08 100644
--- a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
+++ b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
@@ -625,6 +625,7 @@
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper156.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper164.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper168.cs" />
+    <Compile Include="Consoles\Nintendo\NES\Boards\Mapper170.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper175.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper176.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper177.cs" />
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper170.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper170.cs
new file mode 100644
index 0000000000..37f90c2a0f
--- /dev/null
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper170.cs
@@ -0,0 +1,60 @@
+using BizHawk.Common;
+
+namespace BizHawk.Emulation.Cores.Nintendo.NES
+{
+	public sealed class Mapper170 : NES.NESBoardBase
+	{
+		private byte reg;
+
+		public override bool Configure(NES.EDetectionOrigin origin)
+		{
+			switch (Cart.board_type)
+			{
+				case "MAPPER170":
+					break;
+				default:
+					return false;
+			}
+
+			return true;
+		}
+
+		public override void SyncState(Serializer ser)
+		{
+			ser.Sync("reg", ref reg);
+			base.SyncState(ser);
+		}
+
+		public override byte ReadPRG(int addr)
+		{
+			if (addr < 0x4000)
+			{
+				return base.ReadPRG(addr);
+			}
+
+			int last16kBank = ROM.Length - 0x4000;
+			return ROM[last16kBank + (addr & 0x3FFF)];
+		}
+
+		public override void WriteWRAM(int addr, byte value)
+		{
+			if (addr == 0x502 || addr == 0x1000)
+			{
+				reg = (byte)(value << 1 & 0x80);
+			}
+
+
+			base.WriteWRAM(addr, value);
+		}
+
+		public override byte ReadWRAM(int addr)
+		{
+			if (addr == 0x1001 || addr == 0x1777)
+			{
+				return (byte)(reg | NES.DB & 0x7F);
+			}
+
+			return base.ReadWRAM(addr);
+		}
+	}
+}