NESHawk - implement mapper 175

BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj

@@ -621,6 +621,7 @@
     <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\Mapper175.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper176.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper177.cs" />
     <Compile Include="Consoles\Nintendo\NES\Boards\Mapper178.cs" />

BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper175.cs

@@ -0,0 +1,108 @@
+using BizHawk.Common;
+using BizHawk.Common.NumberExtensions;
+
+namespace BizHawk.Emulation.Cores.Nintendo.NES
+{
+	public sealed class Mapper175 : NES.NESBoardBase
+	{
+		private bool delay;
+
+		private int reg;
+		private bool mirr;
+
+		private int chrReg;
+		private int prgReg8;
+		private int prgRegC;
+		private int prgRegE;
+
+		public override bool Configure(NES.EDetectionOrigin origin)
+		{
+			switch (Cart.board_type)
+			{
+				case "MAPPER175":
+					break;
+				default:
+					return false;
+			}
+
+			Sync();
+			return true;
+		}
+
+		public override void SyncState(Serializer ser)
+		{
+			ser.Sync("delay", ref delay);
+
+			ser.Sync("reg", ref reg);
+			ser.Sync("mirr", ref mirr);
+
+			ser.Sync("chrReg", ref chrReg);
+			ser.Sync("prgReg8", ref prgReg8);
+			ser.Sync("prgRegC", ref prgRegC);
+			ser.Sync("prgRegE", ref prgRegE);
+
+
+			base.SyncState(ser);
+		}
+
+		public override void WritePRG(int addr, byte value)
+		{
+			if (addr == 0)
+			{
+				mirr = value.Bit(2);
+				delay = true;
+				Sync();
+			}
+			else if (addr == 0x2000)
+			{
+				reg = value & 0x0F;
+				delay = true;
+				Sync();
+			}
+		}
+
+		private void Sync()
+		{
+			SetMirrorType(mirr ? EMirrorType.Horizontal : EMirrorType.Vertical);
+			chrReg = reg;
+			prgRegE = (reg << 1) + 1;
+			if (!delay)
+			{
+				prgReg8 = reg;
+				prgRegC = reg << 1;
+			}
+		}
+
+		public override byte ReadPPU(int addr)
+		{
+			if (addr < 0x2000)
+			{
+				return VROM[(chrReg << 13) + addr];
+			}
+
+			return base.ReadPPU(addr);
+		}
+
+		public override byte ReadPRG(int addr)
+		{
+			if (addr == 0x7FFC)
+			{
+				delay = false;
+				Sync();
+			}
+
+			if (addr < 0x4000)
+			{
+				return ROM[(prgReg8 << 14) + (addr & 0x3FFF)];
+			}
+			else if (addr < 0x6000)
+			{
+				return ROM[(prgRegC << 13) + (addr & 0x1FFF)];
+			}
+			else
+			{
+				return ROM[(prgRegE << 13) + (addr & 0x1FFF)];
+			}
+		}
+	}
+}