diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Core.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Core.cs
index 783e185b03..999a402920 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Core.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Core.cs
@@ -369,6 +369,11 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 				ret = sysbus_watch[addr].ApplyGameGenie(ret);
 			}
 
+			if (CoreInputComm.MemoryCallbackSystem.ReadCallback != null)
+			{
+				CoreInputComm.MemoryCallbackSystem.TriggerRead(addr);
+			}
+
 			DB = ret;
 
 			return ret;
@@ -420,6 +425,11 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			{
 				board.WritePRG(addr - 0x8000, value);
 			}
+
+			if (CoreInputComm.MemoryCallbackSystem.WriteCallback != null)
+			{
+				CoreInputComm.MemoryCallbackSystem.WriteCallback();
+			}
 		}
 
 	}
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/NES.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/NES.cs
index e372e03497..ba7cc4f52f 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/NES.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/NES.cs
@@ -20,6 +20,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 		{
 			CoreOutputComm = new CoreOutputComm();
 			CoreOutputComm.CpuTraceAvailable = true;
+			CoreInputComm = new BizHawk.CoreInputComm();
 			BootGodDB.Initialize();
 			SetPalette(Palettes.FCEUX_Standard);
 			videoProvider = new MyVideoProvider(this);
diff --git a/BizHawk.Emulation/Consoles/PC Engine/MemoryMap.cs b/BizHawk.Emulation/Consoles/PC Engine/MemoryMap.cs
index ca3a2163a1..c0a661674e 100644
--- a/BizHawk.Emulation/Consoles/PC Engine/MemoryMap.cs	
+++ b/BizHawk.Emulation/Consoles/PC Engine/MemoryMap.cs	
@@ -1,73 +1,83 @@
 namespace BizHawk.Emulation.Consoles.TurboGrafx
 {
-    public partial class PCEngine
-    {
-        byte IOBuffer;
+	public partial class PCEngine
+	{
+		byte IOBuffer;
 
-        byte ReadMemory(int addr)
-        {
-            if (addr < 0xFFFFF) // read ROM
-                return RomData[addr % RomLength];
+		byte ReadMemory(int addr)
+		{
+			if (addr < 0xFFFFF) // read ROM
+				return RomData[addr % RomLength];
 
-            if (addr >= 0x1F0000 && addr < 0x1F8000) // read RAM
-                return Ram[addr & 0x1FFF];
+			if (addr >= 0x1F0000 && addr < 0x1F8000) // read RAM
+				return Ram[addr & 0x1FFF];
 
-            if (addr >= 0x1FE000) // hardware page.
-            {
-                if (addr < 0x1FE400)           return VDC1.ReadVDC(addr);
-                if (addr < 0x1FE800)           { Cpu.PendingCycles--; return VCE.ReadVCE(addr); }
-                if (addr < 0x1FEC00)           return IOBuffer;
-                if (addr < 0x1FF000)           { IOBuffer = (byte) (Cpu.ReadTimerValue() | (IOBuffer & 0x80)); return IOBuffer; }
-                if (addr >= 0x1FF000 && 
-                    addr <  0x1FF400)          { IOBuffer = ReadInput(); return IOBuffer; }
-                if ((addr & ~1) == 0x1FF400)   return IOBuffer;
-                if (addr == 0x1FF402)          { IOBuffer = Cpu.IRQControlByte; return IOBuffer; }
-                if (addr == 0x1FF403)          { IOBuffer = (byte) (Cpu.ReadIrqStatus() | (IOBuffer & 0xF8)); return IOBuffer; }
-                if (addr >= 0x1FF800)          return ReadCD(addr);
-            }
+			if (addr >= 0x1FE000) // hardware page.
+			{
+				if (addr < 0x1FE400) return VDC1.ReadVDC(addr);
+				if (addr < 0x1FE800) { Cpu.PendingCycles--; return VCE.ReadVCE(addr); }
+				if (addr < 0x1FEC00) return IOBuffer;
+				if (addr < 0x1FF000) { IOBuffer = (byte)(Cpu.ReadTimerValue() | (IOBuffer & 0x80)); return IOBuffer; }
+				if (addr >= 0x1FF000 &&
+					addr < 0x1FF400) { IOBuffer = ReadInput(); return IOBuffer; }
+				if ((addr & ~1) == 0x1FF400) return IOBuffer;
+				if (addr == 0x1FF402) { IOBuffer = Cpu.IRQControlByte; return IOBuffer; }
+				if (addr == 0x1FF403) { IOBuffer = (byte)(Cpu.ReadIrqStatus() | (IOBuffer & 0xF8)); return IOBuffer; }
+				if (addr >= 0x1FF800) return ReadCD(addr);
+			}
 
-            if (addr >= 0x1EE000 && addr <= 0x1EE7FF)   // BRAM
-            {
-                if (BramEnabled && BramLocked == false)
-                    return BRAM[addr & 0x7FF];
-                return 0xFF;
-            }
+			if (addr >= 0x1EE000 && addr <= 0x1EE7FF)   // BRAM
+			{
+				if (BramEnabled && BramLocked == false)
+					return BRAM[addr & 0x7FF];
+				return 0xFF;
+			}
 
-            Log.Error("MEM", "UNHANDLED READ: {0:X6}", addr);
-            return 0xFF;
-        }
+			if (CoreInputComm.MemoryCallbackSystem.ReadCallback != null)
+			{
+				CoreInputComm.MemoryCallbackSystem.TriggerRead(addr);
+			}
 
-        void WriteMemory(int addr, byte value)
-        {
-            if (addr >= 0x1F0000 && addr < 0x1F8000) // write RAM.
-                Ram[addr & 0x1FFF] = value;
+			Log.Error("MEM", "UNHANDLED READ: {0:X6}", addr);
+			return 0xFF;
+		}
 
-            else if (addr >= 0x1FE000) // hardware page.
-            {
-                     if (addr <  0x1FE400)     VDC1.WriteVDC(addr, value);
-                else if (addr <  0x1FE800)     { Cpu.PendingCycles--; VCE.WriteVCE(addr, value); }
-                else if (addr <  0x1FEC00)     { IOBuffer = value; PSG.WritePSG((byte)addr, value, Cpu.TotalExecutedCycles); }
-                else if (addr == 0x1FEC00)     { IOBuffer = value; Cpu.WriteTimer(value); }
-                else if (addr == 0x1FEC01)     { IOBuffer = value; Cpu.WriteTimerEnable(value); }
-                else if (addr >= 0x1FF000 && 
-                         addr <  0x1FF400)     { IOBuffer = value; WriteInput(value); }
-                else if (addr == 0x1FF402)     { IOBuffer = value; Cpu.WriteIrqControl(value); }
-                else if (addr == 0x1FF403)     { IOBuffer = value; Cpu.WriteIrqStatus(); }
-                else if (addr >= 0x1FF800)     { WriteCD(addr, value); }
-                else Log.Error("MEM", "unhandled hardware write [{0:X6}] : {1:X2}", addr, value);
-            }
+		void WriteMemory(int addr, byte value)
+		{
+			if (addr >= 0x1F0000 && addr < 0x1F8000) // write RAM.
+				Ram[addr & 0x1FFF] = value;
 
-            else if (addr >= 0x1EE000 && addr <= 0x1EE7FF)   // BRAM
-            {
-                if (BramEnabled && BramLocked == false)
-                {
-                    BRAM[addr & 0x7FF] = value;
-                    SaveRamModified = true;
-                }
-            }
+			else if (addr >= 0x1FE000) // hardware page.
+			{
+				if (addr < 0x1FE400) VDC1.WriteVDC(addr, value);
+				else if (addr < 0x1FE800) { Cpu.PendingCycles--; VCE.WriteVCE(addr, value); }
+				else if (addr < 0x1FEC00) { IOBuffer = value; PSG.WritePSG((byte)addr, value, Cpu.TotalExecutedCycles); }
+				else if (addr == 0x1FEC00) { IOBuffer = value; Cpu.WriteTimer(value); }
+				else if (addr == 0x1FEC01) { IOBuffer = value; Cpu.WriteTimerEnable(value); }
+				else if (addr >= 0x1FF000 &&
+						 addr < 0x1FF400) { IOBuffer = value; WriteInput(value); }
+				else if (addr == 0x1FF402) { IOBuffer = value; Cpu.WriteIrqControl(value); }
+				else if (addr == 0x1FF403) { IOBuffer = value; Cpu.WriteIrqStatus(); }
+				else if (addr >= 0x1FF800) { WriteCD(addr, value); }
+				else Log.Error("MEM", "unhandled hardware write [{0:X6}] : {1:X2}", addr, value);
+			}
 
-            else 
-                Log.Error("MEM","UNHANDLED WRITE: {0:X6}:{1:X2}",addr,value);
-        }
-    }
+			else if (addr >= 0x1EE000 && addr <= 0x1EE7FF)   // BRAM
+			{
+				if (BramEnabled && BramLocked == false)
+				{
+					BRAM[addr & 0x7FF] = value;
+					SaveRamModified = true;
+				}
+			}
+
+			else
+				Log.Error("MEM", "UNHANDLED WRITE: {0:X6}:{1:X2}", addr, value);
+
+			if (CoreInputComm.MemoryCallbackSystem.WriteCallback != null)
+			{
+				CoreInputComm.MemoryCallbackSystem.WriteCallback();
+			}
+		}
+	}
 }
\ No newline at end of file
diff --git a/BizHawk.Emulation/Interfaces/CoreComms.cs b/BizHawk.Emulation/Interfaces/CoreComms.cs
index 8a130dfb69..fc0b6d58ac 100644
--- a/BizHawk.Emulation/Interfaces/CoreComms.cs
+++ b/BizHawk.Emulation/Interfaces/CoreComms.cs
@@ -25,6 +25,8 @@ namespace BizHawk
 		/// for emu.on_snoop()
 		/// </summary>
 		public System.Action InputCallback;
+
+		public MemoryCallbackSystem MemoryCallbackSystem = new MemoryCallbackSystem();
 	}
 
 	public class CoreOutputComm
@@ -93,4 +95,49 @@ namespace BizHawk
 		private StringBuilder buffer;
 		private bool logging = false;
 	}
+
+	public class MemoryCallbackSystem
+	{
+		public int? ReadAddr = null;
+		public System.Action ReadCallback = null;
+
+		public void TriggerRead(int addr)
+		{
+			if (ReadCallback != null)
+			{
+				if (ReadAddr != null)
+				{
+					if (ReadAddr == addr)
+					{
+						ReadCallback();
+					}
+				}
+				else
+				{
+					ReadCallback();
+				}
+			}
+		}
+
+		public int? WriteAddr = null;
+		public System.Action WriteCallback = null;
+
+		public void TriggerWrite(int addr)
+		{
+			if (WriteCallback != null)
+			{
+				if (WriteAddr != null)
+				{
+					if (WriteAddr == addr)
+					{
+						WriteCallback();
+					}
+				}
+				else
+				{
+					WriteCallback();
+				}
+			}
+		}
+	}
 }
diff --git a/BizHawk.MultiClient/LuaImplementation.cs b/BizHawk.MultiClient/LuaImplementation.cs
index aca9a8f2f8..3771e47ec1 100644
--- a/BizHawk.MultiClient/LuaImplementation.cs
+++ b/BizHawk.MultiClient/LuaImplementation.cs
@@ -457,8 +457,6 @@ namespace BizHawk.MultiClient
 		                                             		"write_u32_be",
 															"readbyterange",
 															"writebyterange",
-		                                             		//"registerwrite",
-		                                             		//"registerread",
 		                                             	};
 
 		public static string[] SaveStateFunctions = new string[]
@@ -568,8 +566,8 @@ namespace BizHawk.MultiClient
 														"onsavestate",
 														"onframestart",
 														"onframeend",
-														//"onmemoryread",
-														//"onmemorywrite",
+														"onmemoryread",
+														"onmemorywrite",
 														"oninputpoll",
 													};
 		/****************************************************/
@@ -2683,5 +2681,79 @@ namespace BizHawk.MultiClient
 		{
 			emu_on_snoop(luaf);
 		}
+
+		public void event_onmemoryread(LuaFunction luaf, object address = null)
+		{
+			//TODO: allow a list of addresses
+			if (luaf != null)
+			{
+				int? _addr;
+				if (address == null)
+				{
+					_addr = null;
+				}
+				else
+				{
+					_addr = LuaInt(address);
+				}
+
+				Global.Emulator.CoreInputComm.MemoryCallbackSystem.ReadAddr = _addr;
+				Global.Emulator.CoreInputComm.MemoryCallbackSystem.ReadCallback = delegate()
+				{
+					try
+					{
+						luaf.Call();
+					}
+					catch (SystemException e)
+					{
+						Global.MainForm.LuaConsole1.WriteToOutputWindow(
+							"error running function attached by lua function event.onmemoryread" +
+							"\nError message: " + e.Message);
+					}
+				};
+	
+			}
+			else
+			{
+				Global.Emulator.CoreInputComm.MemoryCallbackSystem.ReadCallback = null;
+			}
+		}
+
+
+		public void event_onmemorywrite(LuaFunction luaf, object address = null)
+		{
+			//TODO: allow a list of addresses
+			if (luaf != null)
+			{
+				int? _addr;
+				if (address == null)
+				{
+					_addr = null;
+				}
+				else
+				{
+					_addr = LuaInt(address);
+				}
+
+				Global.Emulator.CoreInputComm.MemoryCallbackSystem.WriteAddr = _addr;
+				Global.Emulator.CoreInputComm.MemoryCallbackSystem.WriteCallback = delegate()
+				{
+					try
+					{
+						luaf.Call();
+					}
+					catch (SystemException e)
+					{
+						Global.MainForm.LuaConsole1.WriteToOutputWindow(
+							"error running function attached by lua function event.onmemoryread" +
+							"\nError message: " + e.Message);
+					}
+				};
+			}
+			else
+			{
+				Global.Emulator.CoreInputComm.MemoryCallbackSystem.WriteCallback = null;
+			}
+		}
 	}
 }