From faf299faf851fa834eecb6eb47e38dcd96fafe8d Mon Sep 17 00:00:00 2001
From: adelikat <adelikat@expion.com>
Date: Sun, 9 Aug 2015 14:25:49 -0400
Subject: [PATCH] NES - implement mapper 235

---
 .../BizHawk.Emulation.Cores.csproj            |  1 +
 .../Consoles/Nintendo/NES/Boards/Mapper235.cs | 80 +++++++++++++++++++
 2 files changed, 81 insertions(+)
 create mode 100644 BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper235.cs

diff --git a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
index 489158fce0..8cfe7979e0 100644
--- a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
+++ b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
@@ -552,6 +552,7 @@
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper230.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper231.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper233.cs" />
+    <Compile Include="Consoles\Nintendo\NES\Boards\Mapper235.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper240.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper241.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper242.cs" />
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper235.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper235.cs
new file mode 100644
index 0000000000..5d191bf6db
--- /dev/null
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper235.cs
@@ -0,0 +1,80 @@
+using BizHawk.Common;
+
+namespace BizHawk.Emulation.Cores.Nintendo.NES
+{
+	public sealed class Mapper235 : NES.NESBoardBase
+	{
+		private int _reg;
+
+		private int _prg16BankMask;
+		private int _prg32BankMask;
+
+		public override bool Configure(NES.EDetectionOrigin origin)
+		{
+			switch (Cart.board_type)
+			{
+				case "MAPPER235":
+					break;
+				default:
+					return false;
+			}
+
+			_prg16BankMask = Cart.prg_size / 16 - 1;
+			_prg32BankMask = Cart.prg_size / 32 - 1;
+
+			SetMirrorType(Cart.pad_h, Cart.pad_v);
+			return true;
+		}
+
+		public override void SyncState(Serializer ser)
+		{
+			base.SyncState(ser);
+			ser.Sync("reg", ref _reg);
+		}
+
+		public override byte ReadPRG(int addr)
+		{
+			if ((_reg & 0x800) > 0)
+			{
+				int bank;
+				if (addr < 0x4000)
+				{
+					bank = ((_reg & 0x300) >> 3) | ((_reg & 0x1F) << 1) | ((_reg >> 12) & 1);
+					
+				}
+				else
+				{
+					bank = ((_reg & 0x300) >> 3) | ((_reg & 0x1F) << 1) | ((_reg >> 12) & 1);
+					
+				}
+
+				return ROM[((bank & _prg16BankMask) * 0x4000) + (addr & 0x3FFF)];
+			}
+			else
+			{
+				int bank = ((_reg & 0x300) >> 4) | (_reg & 0x1F);
+				return ROM[((bank & _prg32BankMask) * 0x8000) + (addr & 0x7FFF)];
+			}
+		}
+
+		public override void WritePRG(int addr, byte value)
+		{
+			_reg = addr;
+			SyncMirroring();
+		}
+
+		private void SyncMirroring()
+		{
+			if ((_reg & 0x400) > 0)
+			{
+				// TODO
+				SetMirrorType(EMirrorType.Horizontal); // TODO: which one is which?
+			}
+			else
+			{
+				// TODO
+				SetMirrorType(EMirrorType.Vertical);
+			}
+		}
+	}
+}