Wisdom tree Mapper

BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/Mappers/Mapper_WisdomTree.cs

@@ -0,0 +1,60 @@
+using BizHawk.Common;
+using BizHawk.Common.NumberExtensions;
+using System;
+
+namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
+{
+	// Wisdom tree mapper (32K bank switching)
+	public class MapperWT : MapperBase
+	{
+		public int ROM_bank;
+		public int ROM_mask;
+
+		public override void Initialize()
+		{
+			ROM_bank = 1;
+			ROM_mask = Core._rom.Length / 0x8000 - 1;
+
+			// some games have sizes that result in a degenerate ROM, account for it here
+			if (ROM_mask > 4) { ROM_mask |= 3; }
+			if (ROM_mask > 0x100) { ROM_mask |= 0xFF; }
+		}
+
+		public override byte ReadMemory(ushort addr)
+		{
+			if (addr < 0x8000)
+			{
+				return Core._rom[ROM_bank * 0x8000 + addr];
+			}
+			else
+			{
+				return 0xFF;
+			}
+		}
+
+		public override byte PeekMemory(ushort addr)
+		{
+			return ReadMemory(addr);
+		}
+
+		public override void WriteMemory(ushort addr, byte value)
+		{
+			if (addr < 0x4000)
+			{
+				ROM_bank = ((addr << 1) & 0x1ff) >> 1;
+				ROM_bank &= ROM_mask;
+			}
+		}
+
+		public override void PokeMemory(ushort addr, byte value)
+		{
+			WriteMemory(addr, value);
+		}
+
+		public override void SyncState(Serializer ser)
+		{
+			ser.Sync("ROM_Bank", ref ROM_bank);
+			ser.Sync("ROM_Mask", ref ROM_mask);
+		}
+	}
+}