From ce1ec1e7665490eeac9ad9f6c1887bbcd169db9b Mon Sep 17 00:00:00 2001
From: adelikat <adelikat@tasvideos.org>
Date: Sat, 22 Aug 2015 11:17:11 -0400
Subject: [PATCH] NesHawk - implement board UNIF_BMC-A65AS

---
 .../BizHawk.Emulation.Cores.csproj            |  1 +
 .../NES/Boards/UNIF/UNIF_BMC-A65AS.cs         | 83 +++++++++++++++++++
 2 files changed, 84 insertions(+)
 create mode 100644 BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/UNIF/UNIF_BMC-A65AS.cs

diff --git a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
index f2fe0b8ea3..9feb51d1c5 100644
--- a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
+++ b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
@@ -638,6 +638,7 @@
     <Compile Include="Consoles\Nintendo\NES\Boards\TENGEN-800032.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\TENGEN_800008.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\UNIF\UNIF-DREAMTECH01.cs" />
+    <Compile Include="Consoles\Nintendo\NES\Boards\UNIF\UNIF_BMC-A65AS.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\UNIF\UNIF_BMC-T-262.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\UxROM.cs">
       <SubType>Code</SubType>
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/UNIF/UNIF_BMC-A65AS.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/UNIF/UNIF_BMC-A65AS.cs
new file mode 100644
index 0000000000..f6423166f4
--- /dev/null
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/UNIF/UNIF_BMC-A65AS.cs
@@ -0,0 +1,83 @@
+using BizHawk.Common;
+using BizHawk.Common.NumberExtensions;
+
+namespace BizHawk.Emulation.Cores.Nintendo.NES
+{
+	public class UNIF_BMC_A65AS : NES.NESBoardBase
+	{
+		private int _prgReg;
+		private bool _isPrg32kMode;
+
+		private int prgMask16k;
+		private int prgMask32k;
+
+		public override bool Configure(NES.EDetectionOrigin origin)
+		{
+			switch (Cart.board_type)
+			{
+				case "UNIF_BMC-A65AS":
+					break;
+				default:
+					return false;
+			}
+
+			prgMask16k = Cart.prg_size / 16 - 1;
+			prgMask32k = Cart.prg_size / 32 - 1;
+
+			return true;
+		}
+
+		public override void SyncState(Serializer ser)
+		{
+			base.SyncState(ser);
+			ser.Sync("prgReg", ref _prgReg);
+			ser.Sync("isPrg32kMode", ref _isPrg32kMode);
+		}
+
+		public override void WritePRG(int addr, byte value)
+		{
+			_isPrg32kMode = value.Bit(6);
+			_prgReg = value;
+
+			// From FCEUX:
+			// actually, there is two cart in one... First have extra mirroring
+			// mode (one screen) and 32K bankswitching, second one have only
+			// 16 bankswitching mode and normal mirroring... But there is no any
+			// correlations between modes and they can be used in one mapper code.
+			if (value.Bit(7))
+			{
+				 SetMirrorType(value.Bit(5) ? EMirrorType.OneScreenB : EMirrorType.OneScreenA);
+			}
+			else
+			{
+				SetMirrorType(value.Bit(3) ? EMirrorType.Horizontal : EMirrorType.Vertical);
+			}
+		}
+
+		public override byte ReadPRG(int addr)
+		{
+			if (_isPrg32kMode)
+			{
+				int bank = (_prgReg >> 1) & 0xF;
+				bank &= prgMask32k;
+				return ROM[(bank * 0x8000) + (addr & 0x7FFF)];
+			}
+			else
+			{
+				
+				if (addr < 0x4000)
+				{
+					int bank = (_prgReg & 0x30) >> 1 | _prgReg & 7;
+					bank &= prgMask16k;
+					return ROM[(bank * 0x4000) + (addr & 0x3FFF)];
+				}
+				else
+				{
+					int bank = (_prgReg & 0x30) >> 1 | 7;
+					bank &= prgMask16k;
+					return ROM[(bank * 0x4000) + (addr & 0x3FFF)];
+				}
+			}
+		}
+	}
+}