diff --git a/BizHawk.Client.EmuHawk/tools/CDL.cs b/BizHawk.Client.EmuHawk/tools/CDL.cs
index af2124f9a1..41759c0972 100644
--- a/BizHawk.Client.EmuHawk/tools/CDL.cs
+++ b/BizHawk.Client.EmuHawk/tools/CDL.cs
@@ -154,6 +154,12 @@ namespace BizHawk.Client.EmuHawk
 				{
 					var gambatte = _emu as Gameboy;
 					var cdl_gb = newCDL as CodeDataLog_GB;
+					var memd = gambatte.AsMemoryDomains();
+					if (!cdl_gb.CheckConsistency(memd))
+					{
+						MessageBox.Show(this, "CDL file does not match emulator's current memory map!");
+						return;
+					}
 					gambatte.CDL = cdl_gb;
 				}
 			}
@@ -351,7 +357,10 @@ namespace BizHawk.Client.EmuHawk
 				pce.Cpu.CDLLoggingActive = LoggingActiveCheckbox.Checked;
 			}
 
-			_cdl.Active = LoggingActiveCheckbox.Checked;
+			//zeromus doesnt like this kind of logic
+
+			if (_cdl != null)
+				_cdl.Active = LoggingActiveCheckbox.Checked;
 		}
 
 		private void PCECDL_DragEnter(object sender, DragEventArgs e)
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/CodeDataLog_GB.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/CodeDataLog_GB.cs
index c4321fe2fc..0b5c18f54d 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/CodeDataLog_GB.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/CodeDataLog_GB.cs
@@ -10,14 +10,30 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 		public static CodeDataLog_GB Create(IMemoryDomains memdomains)
 		{
 			var t = new CodeDataLog_GB();
+			
 			t["ROM"] = new byte[memdomains["ROM"].Size];
+			
 			//t["HRAM"] = new byte[memdomains["HRAM"].Size]; //this is probably useless, but it's here if someone needs it
 			t["WRAM"] = new byte[memdomains["WRAM"].Size];
-			t["CartRAM"] = new byte[memdomains["Cart RAM"].Size];
+
+			if(memdomains.Has("CartRAM"))
+				t["CartRAM"] = new byte[memdomains["WRAM"].Size];
+
 			return t;
 		}
 
 		public override string SubType { get { return "GB"; } }
 		public override int SubVer { get { return 0; } }
+
+		//todo - this could be base classed
+		public bool CheckConsistency(IMemoryDomains memdomains)
+		{
+			if (memdomains["ROM"].Size != this["ROM"].Length) return false;
+			if (memdomains["WRAM"].Size != this["WRAM"].Length) return false;
+			if(memdomains.Has("CartRAM"))
+				if (memdomains["CartRAM"].Size != this["CartRAM"].Length) 
+					return false;
+			return true;
+		}
 	}
 }
\ No newline at end of file
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.IMemoryDomains.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.IMemoryDomains.cs
index e5e7e9b95a..2eccb2deec 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.IMemoryDomains.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.IMemoryDomains.cs
@@ -29,7 +29,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 			CreateMemoryDomain(LibGambatte.MemoryAreas.wram, "WRAM");
 			CreateMemoryDomain(LibGambatte.MemoryAreas.rom, "ROM");
 			CreateMemoryDomain(LibGambatte.MemoryAreas.vram, "VRAM");
-			CreateMemoryDomain(LibGambatte.MemoryAreas.cartram, "Cart RAM");
+			CreateMemoryDomain(LibGambatte.MemoryAreas.cartram, "CartRAM");
 			CreateMemoryDomain(LibGambatte.MemoryAreas.oam, "OAM");
 			CreateMemoryDomain(LibGambatte.MemoryAreas.hram, "HRAM");
 
diff --git a/libgambatte/src/mem/cartridge.cpp b/libgambatte/src/mem/cartridge.cpp
index 6ce6795e8a..b8b642f4c4 100644
--- a/libgambatte/src/mem/cartridge.cpp
+++ b/libgambatte/src/mem/cartridge.cpp
@@ -710,7 +710,7 @@ void Cartridge::saveSavedata(char *dest) {
 	}
 }
 
-bool Cartridge::getMemoryArea(int which, unsigned char **data, int *length) {
+bool Cartridge::getMemoryArea(int which, unsigned char **data, int *length) const {
 	if (!data || !length)
 		return false;
 
diff --git a/libgambatte/src/mem/cartridge.h b/libgambatte/src/mem/cartridge.h
index 4038593d23..54f694df31 100644
--- a/libgambatte/src/mem/cartridge.h
+++ b/libgambatte/src/mem/cartridge.h
@@ -95,7 +95,7 @@ public:
 	int saveSavedataLength();
 	void saveSavedata(char *dest);
 
-	bool getMemoryArea(int which, unsigned char **data, int *length);
+	bool getMemoryArea(int which, unsigned char **data, int *length) const;
 
 	int loadROM(const char *romfiledata, unsigned romfilelength, bool forceDmg, bool multicartCompat);
 	const char * romTitle() const { return reinterpret_cast<const char *>(memptrs.romdata() + 0x134); }
diff --git a/libgambatte/src/memory.h b/libgambatte/src/memory.h
index b6a4bafd24..75263e66d4 100644
--- a/libgambatte/src/memory.h
+++ b/libgambatte/src/memory.h
@@ -144,10 +144,16 @@ public:
 		{
 			if(cart.wsrambankptr())
 			{
-				//not bankable
-				unsigned addr = P&0x1FFF;
-				CDMapResult ret = { eCDLog_AddrType_CartRAM, addr };
-				return ret;
+				//not bankable. but. we're not sure how much might be here
+				unsigned char *data;
+				int length;
+				bool has = cart.getMemoryArea(3,&data,&length);
+				unsigned addr = P&(length-1);
+				if(has && length!=0)
+				{
+					CDMapResult ret = { eCDLog_AddrType_CartRAM, addr };
+					return ret;
+				}
 			}
 		}
 		else if(P<0xE000)
diff --git a/output/dll/libgambatte.dll b/output/dll/libgambatte.dll
index bb85ac5da6..226f1b0f85 100644
Binary files a/output/dll/libgambatte.dll and b/output/dll/libgambatte.dll differ