diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/NES.Core.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/NES.Core.cs
index 6f617561bc8..5af64419883 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/NES.Core.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/NES.Core.cs
@@ -151,6 +151,8 @@ public void Dispose()
 		public void HardReset()
 		{
 			cpu = new MOS6502X();
+			RegisterReadDelegates();
+			RegisterWriteDelegates();
 			cpu.SetCallbacks(ReadMemory, ReadMemory, PeekMemory, WriteMemory);
 
 			cpu.BCD_Enabled = false;
@@ -659,38 +661,83 @@ public void ExecFetch(ushort addr)
 			MemoryCallbacks.CallExecutes(addr);
 		}
 
-		public byte ReadMemory(ushort addr)
+		private delegate byte ReadMemoryDelegate(ushort addr);
+
+		public byte ReadROM(ushort addr)
 		{
-			byte ret;
-			
-			if (addr >= 0x8000)
-			{
-				ret = Board.ReadPRG(addr - 0x8000); //easy optimization, since rom reads are so common, move this up (reordering the rest of these elseifs is not easy)
-			}
-			else if (addr < 0x0800)
-			{
-				ret = ram[addr];
-			}
-			else if (addr < 0x2000)
-			{
-				ret = ram[addr & 0x7FF];
-			}
-			else if (addr < 0x4000)
-			{
-				ret = Board.ReadReg2xxx(addr);
-			}
-			else if (addr < 0x4020)
-			{
-				ret = ReadReg(addr); //we're not rebasing the register just to keep register names canonical			
-			}
-			else if (addr < 0x6000)
-			{
-				ret = Board.ReadEXP(addr - 0x4000);
-			}
-			else
+			return Board.ReadPRG(addr - 0x8000);
+		}
+
+		public byte ReadRAM(ushort addr)
+		{
+			return ram[addr];
+		}
+
+		public byte ReadRAMMirrors(ushort addr)
+		{
+			return ram[addr & 0x7FF];
+		}
+
+		public byte ReadReg2xxx(ushort addr)
+		{
+			return Board.ReadReg2xxx(addr);
+		}
+
+		public byte ReadRegDelegate(ushort addr)
+		{
+			return ReadReg(addr);
+		}
+
+		public byte ReadEXP(ushort addr)
+		{
+			return Board.ReadEXP(addr - 0x4000);
+		}
+
+		public byte ReadWRAM(ushort addr)
+		{
+			return Board.ReadWRAM(addr - 0x6000);
+		}
+
+		ReadMemoryDelegate[] ReadDelegates = new ReadMemoryDelegate[0x10000];
+
+		private void RegisterReadDelegates()
+		{
+			for (int addr = 0; addr < 0x10000; addr++)
 			{
-				ret = Board.ReadWRAM(addr - 0x6000);
+				if (addr >= 0x8000)
+				{
+					ReadDelegates[addr] = new ReadMemoryDelegate(ReadROM);
+				}
+				else if (addr < 0x0800)
+				{
+					ReadDelegates[addr] = new ReadMemoryDelegate(ReadRAM);
+				}
+				else if (addr < 0x2000)
+				{
+					ReadDelegates[addr] = new ReadMemoryDelegate(ReadRAMMirrors);
+				}
+				else if (addr < 0x4000)
+				{
+					ReadDelegates[addr] = new ReadMemoryDelegate(ReadReg2xxx);
+				}
+				else if (addr < 0x4020)
+				{
+					ReadDelegates[addr] = new ReadMemoryDelegate(ReadRegDelegate);		
+				}
+				else if (addr < 0x6000)
+				{
+					ReadDelegates[addr] = new ReadMemoryDelegate(ReadEXP);
+				}
+				else
+				{
+					continue;
+				}
 			}
+		}
+
+		public byte ReadMemory(ushort addr)
+		{
+			byte ret = ReadDelegates[addr](addr);
 			
 			//handle breakpoints and stuff.
 			//the idea is that each core can implement its own watch class on an address which will track all the different kinds of monitors and breakpoints and etc.
@@ -723,36 +770,83 @@ public void RemoveGameGenie(int addr)
 			}
 		}
 
-		public void WriteMemory(ushort addr, byte value)
+		public delegate void WriteMemoryDelegate(ushort addr, byte value);
+
+		public void WriteROM(ushort addr, byte value)
 		{
-			if (addr < 0x0800)
-			{
-				ram[addr] = value;
-			}
-			else if (addr < 0x2000)
-			{
-				ram[addr & 0x7FF] = value;
-			}
-			else if (addr < 0x4000)
-			{
-				Board.WriteReg2xxx(addr,value);
-			}
-			else if (addr < 0x4020)
-			{
-				WriteReg(addr, value);  //we're not rebasing the register just to keep register names canonical
-			}
-			else if (addr < 0x6000)
-			{
-				Board.WriteEXP(addr - 0x4000, value);
-			}
-			else if (addr < 0x8000)
-			{
-				Board.WriteWRAM(addr - 0x6000, value);
-			}
-			else
+			Board.WritePRG(addr - 0x8000, value);
+		}
+
+		public void WriteRAM(ushort addr, byte value)
+		{
+			ram[addr] = value;
+		}
+
+		public void WriteRAMMirrors(ushort addr, byte value)
+		{
+			ram[addr & 0x7FF] = value;
+		}
+
+		public void WriteReg2xxx(ushort addr, byte value)
+		{
+			Board.WriteReg2xxx(addr, value);
+		}
+
+		public void WriteRegDelegate(ushort addr, byte value)
+		{
+			WriteReg(addr, value);
+		}
+
+		public void WriteEXP(ushort addr, byte value)
+		{
+			Board.WriteEXP(addr - 0x4000, value);
+		}
+
+		public void WriteWRAM(ushort addr, byte value)
+		{
+			Board.WriteWRAM(addr - 0x6000, value);
+		}
+
+		WriteMemoryDelegate[] WriteDelegates = new WriteMemoryDelegate[0x10000];
+
+		private void RegisterWriteDelegates()
+		{
+			for (int addr = 0; addr < 0x10000; addr++)
 			{
-				Board.WritePRG(addr - 0x8000, value);
+				if (addr >= 0x8000)
+				{
+					WriteDelegates[addr] = new WriteMemoryDelegate(WriteROM);
+				}
+				else if (addr < 0x0800)
+				{
+					WriteDelegates[addr] = new WriteMemoryDelegate(WriteRAM);
+				}
+				else if (addr < 0x2000)
+				{
+					WriteDelegates[addr] = new WriteMemoryDelegate(WriteRAMMirrors);
+				}
+				else if (addr < 0x4000)
+				{
+					WriteDelegates[addr] = new WriteMemoryDelegate(WriteReg2xxx);
+				}
+				else if (addr < 0x4020)
+				{
+					WriteDelegates[addr] = new WriteMemoryDelegate(WriteRegDelegate);
+				}
+				else if (addr < 0x6000)
+				{
+					WriteDelegates[addr] = new WriteMemoryDelegate(WriteEXP);
+				}
+				else
+				{
+					continue;
+				}
 			}
+		}
+
+		public void WriteMemory(ushort addr, byte value)
+		{
+			WriteDelegates[addr](addr, value);
 
 			MemoryCallbacks.CallWrites(addr);
 		}