From 2e6ba683278689b851417bf341616f02cf774404 Mon Sep 17 00:00:00 2001
From: adelikat <adelikat@tasvideos.org>
Date: Sun, 23 Aug 2015 22:26:10 -0400
Subject: [PATCH] NesHawk - TEN MILLION IN ONE!!!111

---
 .../BizHawk.Emulation.Cores.csproj            |  1 +
 .../Consoles/Nintendo/NES/Boards/Mapper212.cs | 80 +++++++++++++++++++
 2 files changed, 81 insertions(+)
 create mode 100644 BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper212.cs

diff --git a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
index e127421c3d..e85ce537b2 100644
--- a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
+++ b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
@@ -550,6 +550,7 @@
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper202.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper203.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper204.cs" />
+    <Compile Include="Consoles\Nintendo\NES\Boards\Mapper212.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper214.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper218.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper222.cs" />
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper212.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper212.cs
new file mode 100644
index 0000000000..1560412862
--- /dev/null
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper212.cs
@@ -0,0 +1,80 @@
+using BizHawk.Common;
+using BizHawk.Common.NumberExtensions;
+
+namespace BizHawk.Emulation.Cores.Nintendo.NES
+{
+	// 1997-in-1
+	// 999999-in-1
+	// 1000000-in-1
+	// http://wiki.nesdev.com/w/index.php/INES_Mapper_212
+	public class Mapper212 : NES.NESBoardBase
+	{
+		private int _reg;
+
+		public override bool Configure(NES.EDetectionOrigin origin)
+		{
+			switch (Cart.board_type)
+			{
+				case "MAPPER212":
+					break;
+				default:
+					return false;
+			}
+
+			SetMirrorType(Cart.pad_h, Cart.pad_v);
+
+			_reg = 65535;
+
+			return true;
+		}
+
+		public override void SyncState(Serializer ser)
+		{
+			base.SyncState(ser);
+			ser.Sync("_reg", ref _reg);
+		}
+
+		public override void WritePRG(int addr, byte value)
+		{
+			addr += 0x8000;
+
+			_reg = addr;
+			SetMirrorType(addr.Bit(3) ? EMirrorType.Horizontal : EMirrorType.Vertical);
+		}
+
+		public override byte ReadPRG(int addr)
+		{
+			addr += 0x8000;
+			byte ret;
+
+			if ((_reg & 0x4000) > 0)
+			{
+				int bank = (_reg >> 1) & 3;
+				ret = ROM[(bank * 0x8000) + (addr & 0x7FFF)];
+			}
+			else
+			{
+				int bank = _reg & 7;
+				ret = ROM[(bank * 0x4000) + (addr & 0x3FFF)];
+			}
+			
+			if ((addr & 0xE010) == 0x6000)
+			{
+				ret |= 0x80;
+			}
+
+			return ret;
+		}
+
+		public override byte ReadPPU(int addr)
+		{
+			if (addr < 0x2000)
+			{
+				int bank = _reg & 7;
+				return VROM[(bank * 0x2000) + (addr & 0x1FFF)];
+			}
+
+			return base.ReadPPU(addr);
+		}
+	}
+}