From ef656a9f5d6f8f33e1290026b4c99386c3e5291d Mon Sep 17 00:00:00 2001
From: adelikat <adelikat@expion.com>
Date: Sun, 9 Aug 2015 13:41:45 -0400
Subject: [PATCH] Implement Mapper 244 (Decathlon)

---
 .../BizHawk.Emulation.Cores.csproj            |  1 +
 .../Consoles/Nintendo/NES/Boards/Mapper244.cs | 78 +++++++++++++++++++
 2 files changed, 79 insertions(+)
 create mode 100644 BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper244.cs

diff --git a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
index 8a2ecc281d..489158fce0 100644
--- a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
+++ b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
@@ -558,6 +558,7 @@
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper078.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper046.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper243.cs" />
+    <Compile Include="Consoles\Nintendo\NES\Boards\Mapper244.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper246.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper50.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper60.cs" />
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper244.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper244.cs
new file mode 100644
index 0000000000..f8a15ec954
--- /dev/null
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper244.cs
@@ -0,0 +1,78 @@
+using System.Collections.Generic;
+using BizHawk.Common;
+
+namespace BizHawk.Emulation.Cores.Nintendo.NES
+{
+	public class Mapper244 : NES.NESBoardBase
+	{
+		public override bool Configure(NES.EDetectionOrigin origin)
+		{
+			switch (Cart.board_type)
+			{
+				case "MAPPER244":
+					break;
+				default:
+					return false;
+			}
+
+			return true;
+		}
+
+		private List<List<byte>> prg_perm = new List<List<byte>>
+		{
+			new List<byte> { 0, 1, 2, 3, },
+			new List<byte> { 3, 2, 1, 0, },
+			new List<byte> { 0, 2, 1, 3, },
+			new List<byte> { 3, 1, 2, 0, },
+		};
+
+		private List<List<byte>> chr_perm = new List<List<byte>>
+		{
+			new List<byte> { 0, 1, 2, 3, 4, 5, 6, 7, },
+			new List<byte> { 0, 2, 1, 3, 4, 6, 5, 7, },
+			new List<byte> { 0, 1, 4, 5, 2, 3, 6, 7, },
+			new List<byte> { 0, 4, 1, 5, 2, 6, 3, 7, },
+			new List<byte> { 0, 4, 2, 6, 1, 5, 3, 7, },
+			new List<byte> { 0, 2, 4, 6, 1, 3, 5, 7, },
+			new List<byte> { 7, 6, 5, 4, 3, 2, 1, 0, },
+			new List<byte> { 7, 6, 5, 4, 3, 2, 1, 0, }
+		};
+
+		private int _chrRegister = 0;
+		private int _prgRegister = 0;
+
+		public override void SyncState(Serializer ser)
+		{
+			base.SyncState(ser);
+			ser.Sync("chrRegister", ref _chrRegister);
+			ser.Sync("prgRegister", ref _prgRegister);
+		}
+
+		public override byte ReadPPU(int addr)
+		{
+			if (addr < 0x2000)
+			{
+				return VROM[(_chrRegister * 0x2000) + (addr & 0x1FFF)];
+			}
+
+			return base.ReadPPU(addr);
+		}
+
+		public override byte ReadPRG(int addr)
+		{
+			return ROM[(_prgRegister * 0x8000) + (addr & 0x7FFF)];
+		}
+
+		public override void WritePRG(int addr, byte value)
+		{
+			if ((value & 0x08) > 0)
+			{
+				_chrRegister = chr_perm[(value >> 4) & 7][value & 7];
+			}
+			else
+			{
+				_prgRegister = prg_perm[(value >> 4) & 3][value & 3];
+			}
+		}
+	}
+}