diff --git a/desmume/src/addons.cpp b/desmume/src/addons.cpp
index 41100a168..2463496b8 100644
--- a/desmume/src/addons.cpp
+++ b/desmume/src/addons.cpp
@@ -41,6 +41,7 @@ extern ADDONINTERFACE addonCFlash;
 extern ADDONINTERFACE addonRumblePak;
 extern ADDONINTERFACE addonGBAgame;
 extern ADDONINTERFACE addonGuitarGrip;
+extern ADDONINTERFACE addonExpMemory;
 //extern ADDONINTERFACE addonExternalMic;
 
 ADDONINTERFACE addonList[NDS_ADDON_COUNT] = {
@@ -48,7 +49,8 @@ ADDONINTERFACE addonList[NDS_ADDON_COUNT] = {
 		addonCFlash,
 		addonRumblePak,
 		addonGBAgame,
-		addonGuitarGrip
+		addonGuitarGrip,
+		addonExpMemory
 };
 
 ADDONINTERFACE	addon = addonCFlash;		// default none pak
diff --git a/desmume/src/addons.h b/desmume/src/addons.h
index 4b6a7b2ff..9c5dbfc52 100644
--- a/desmume/src/addons.h
+++ b/desmume/src/addons.h
@@ -66,6 +66,7 @@ enum {
 	NDS_ADDON_RUMBLEPAK,	// rumble pack
 	NDS_ADDON_GBAGAME,		// gba game in slot
 	NDS_ADDON_GUITARGRIP,	// Guitar Grip
+	NDS_ADDON_EXPMEMORY,	// Memory Expansion 
 	//NDS_ADDON_EXTERNALMIC,
 	NDS_ADDON_COUNT		// use for counter addons - MUST TO BE LAST!!!
 };
diff --git a/desmume/src/addons/expMemory.cpp b/desmume/src/addons/expMemory.cpp
new file mode 100644
index 000000000..9b5ee670d
--- /dev/null
+++ b/desmume/src/addons/expMemory.cpp
@@ -0,0 +1,151 @@
+/*  Copyright (C) 2006 yopyop
+    yopyop156@ifrance.com
+    yopyop156.ifrance.com
+
+    Copyright (C) 2009 CrazyMax
+	Copyright (C) 2009 DeSmuME team
+
+    This file is part of DeSmuME
+
+    DeSmuME is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    DeSmuME is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with DeSmuME; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
+*/
+
+#include "../addons.h"
+#include "../mem.h"
+#include <string.h>
+#include "../MMU.h"
+
+u8		*expMemory	=	NULL;
+u32		expMemSize = 8 * 1024 * 1024; // 8Mb
+
+#if 0
+#define EXPINFO(...) INFO(__VA_ARGS__)
+#else
+#define EXPINFO(...)
+#endif 
+
+static BOOL ExpMemory_init(void) { return (TRUE); }
+static void ExpMemory_reset(void)
+{
+	if (expMemory)
+	{
+		delete [] expMemory;
+		expMemory = NULL;
+	}
+	expMemory = new u8 [expMemSize];
+	memset(expMemory, 0xFF, expMemSize);
+}
+static void ExpMemory_close(void)
+{
+	if (expMemory)
+	{
+		delete [] expMemory;
+		expMemory = NULL;
+	}
+}
+static void ExpMemory_config(void) {}
+static void ExpMemory_write08(u32 adr, u8 val) 
+{
+	
+	if (adr >= 0x09000000)
+	{
+		u32 offs = (adr - 0x09000000);
+		if (offs >= expMemSize) return;
+		T1WriteByte(expMemory, offs, val);
+	}
+	EXPINFO("ExpMemory: write 08 at 0x%08X = 0x%02X\n", adr, val);
+}
+static void ExpMemory_write16(u32 adr, u16 val) 
+{
+	
+	if (adr >= 0x09000000)
+	{
+		u32 offs = (adr - 0x09000000);
+		if (offs >= expMemSize) return;
+		T1WriteWord(expMemory, offs, val);
+	}
+	EXPINFO("ExpMemory: write 16 at 0x%08X = 0x%04X\n", adr, val);
+}
+static void ExpMemory_write32(u32 adr, u32 val) 
+{
+	
+	if (adr >= 0x09000000)
+	{
+		u32 offs = (adr - 0x09000000);
+		if (offs >= expMemSize) return;
+		T1WriteLong(expMemory, offs, val);
+	}
+	EXPINFO("ExpMemory: write 32 at 0x%08X = 0x%08X\n", adr, val);
+}
+static u8   ExpMemory_read08(u32 adr)
+{
+	if (adr == 0x080000B2) return(0x96);
+
+	if (adr >= 0x09000000)
+	{
+		u32 offs = (adr - 0x09000000);
+		if (offs >= expMemSize) return (0);
+		return (T1ReadByte(expMemory, offs));
+	}
+
+	EXPINFO("ExpMemory: read 08 at 0x%08X\n", adr);
+	return (0);
+}
+static u16  ExpMemory_read16(u32 adr)
+{
+	if (adr == 0x080000B6) return(0x2424);
+	if (adr == 0x080000BC) return(0x7FFF);
+	if (adr == 0x080000BE) return(0x0096);
+	if (adr == 0x0801FFFC) return(0x7FFF);
+
+	if (adr >= 0x09000000)
+	{
+		u32 offs = (adr - 0x09000000);
+		if (offs >= expMemSize) return (0);
+		return (T1ReadWord(expMemory, offs));
+	}
+
+	EXPINFO("ExpMemory: read 16 at 0x%08X\n", adr);
+	return (0);
+}
+static u32  ExpMemory_read32(u32 adr)
+{
+	if (adr == 0x080000AC) return(0x027FFC30);
+
+	if (adr >= 0x09000000)
+	{
+		u32 offs = (adr - 0x09000000);
+		if (offs >= expMemSize) return (0);
+		return (T1ReadLong(expMemory, offs));
+	}
+
+	EXPINFO("ExpMemory: read 32 at 0x%08X\n", adr);
+	return (0);
+}
+static void ExpMemory_info(char *info) { strcpy(info, "Memory Expansion Pak"); }
+
+ADDONINTERFACE addonExpMemory = {
+				"Memory Expansion Pak",
+				ExpMemory_init,
+				ExpMemory_reset,
+				ExpMemory_close,
+				ExpMemory_config,
+				ExpMemory_write08,
+				ExpMemory_write16,
+				ExpMemory_write32,
+				ExpMemory_read08,
+				ExpMemory_read16,
+				ExpMemory_read32,
+				ExpMemory_info};
diff --git a/desmume/src/addons/gbagame.cpp b/desmume/src/addons/gbagame.cpp
index 1cec71e58..e68252432 100644
--- a/desmume/src/addons/gbagame.cpp
+++ b/desmume/src/addons/gbagame.cpp
@@ -38,12 +38,17 @@ static u8		*GBArom = NULL;
 
 static BOOL GBAgame_init(void)
 {
-	GBArom = new u8 [GBA_SIZE];
 	return (TRUE); 
 }
 
 static void GBAgame_reset(void)
 {
+	if (GBArom)
+	{
+		delete [] GBArom;
+		GBArom = NULL;
+	}
+	GBArom = new u8 [GBA_SIZE];
 	memset(GBArom, 0, GBA_SIZE);
 
 	if (!strlen(GBAgameName)) return;
@@ -80,8 +85,11 @@ static void GBAgame_reset(void)
 
 static void GBAgame_close(void)
 {
-	delete[] GBArom;
-	GBArom = NULL;
+	if (GBArom)
+	{
+		delete [] GBArom;
+		GBArom = NULL;
+	}
 }
 
 static void GBAgame_config(void) {}
diff --git a/desmume/src/bios.cpp b/desmume/src/bios.cpp
index 2ae04a9ac..226c830f5 100644
--- a/desmume/src/bios.cpp
+++ b/desmume/src/bios.cpp
@@ -328,7 +328,7 @@ TEMPLATE static u32 divide()
      cpu->R[0] = (u32)(num / dnum);
      cpu->R[1] = (u32)(num % dnum);
      cpu->R[3] = (u32) (((s32)cpu->R[0])<0 ? -(s32)cpu->R[0] : cpu->R[0]);
-     
+
      return 6;
 }
 
@@ -857,17 +857,37 @@ TEMPLATE static u32 BitUnPack()
   dest = cpu->R[1];
   header = cpu->R[2];
 
-  //INFO("swi bitunpack\n");
-  
   len = _MMU_read16<PROCNUM>(header);
-  // check address
   bits = _MMU_read08<PROCNUM>(header+2);
+  switch (bits)
+  {
+	case 1:
+	case 2:
+	case 4:
+	case 8:
+	  break;
+	default: return (0);	// error
+  }
+  dataSize = _MMU_read08<PROCNUM>(header+3);
+  switch (dataSize)
+  {
+	case 1:
+	case 2:
+	case 4:
+	case 8:
+	case 16:
+	case 32:
+	  break;
+	default: return (0);	// error
+  }
+
   revbits = 8 - bits; 
   // u32 value = 0;
   base = _MMU_read08<PROCNUM>(header+4);
   addBase = (base & 0x80000000) ? 1 : 0;
   base &= 0x7fffffff;
-  dataSize = _MMU_read08<PROCNUM>(header+3);
+  
+  //INFO("SWI10: bitunpack src 0x%08X dst 0x%08X hdr 0x%08X (src len %05i src bits %02i dst bits %02i)\n\n", source, dest, header, len, bits, dataSize);
 
   data = 0; 
   bitwritecount = 0; 
diff --git a/desmume/src/emufile.h b/desmume/src/emufile.h
index 5218bea16..2ec209689 100644
--- a/desmume/src/emufile.h
+++ b/desmume/src/emufile.h
@@ -132,7 +132,7 @@ public:
 
 	virtual size_t _fread(const void *ptr, size_t bytes){
 		u32 remain = len-pos;
-		u32 todo = std::min(remain,bytes);
+		u32 todo = std::min<u32>(remain,bytes);
 		memcpy((void*)ptr,buf()+pos,todo);
 		pos += todo;
 		if(todo<bytes)
diff --git a/desmume/src/windows/DeSmuME_2005.vcproj b/desmume/src/windows/DeSmuME_2005.vcproj
index 9648a8f7e..b2c75c315 100644
--- a/desmume/src/windows/DeSmuME_2005.vcproj
+++ b/desmume/src/windows/DeSmuME_2005.vcproj
@@ -1057,6 +1057,10 @@
 				RelativePath="..\addons\compactFlash.cpp"
 				>
 			</File>
+			<File
+				RelativePath="..\addons\expMemory.cpp"
+				>
+			</File>
 			<File
 				RelativePath="..\addons\gbagame.cpp"
 				>
diff --git a/desmume/src/windows/DeSmuME_2008.vcproj b/desmume/src/windows/DeSmuME_2008.vcproj
index a698ac381..e31b5273a 100644
--- a/desmume/src/windows/DeSmuME_2008.vcproj
+++ b/desmume/src/windows/DeSmuME_2008.vcproj
@@ -832,6 +832,10 @@
 						RelativePath="..\addons\compactFlash.cpp"
 						>
 					</File>
+					<File
+						RelativePath="..\addons\expMemory.cpp"
+						>
+					</File>
 					<File
 						RelativePath="..\addons\gbagame.cpp"
 						>
diff --git a/desmume/src/windows/DeSmuME_2010.vcxproj b/desmume/src/windows/DeSmuME_2010.vcxproj
index 92b0afd68..8a471e79d 100644
--- a/desmume/src/windows/DeSmuME_2010.vcxproj
+++ b/desmume/src/windows/DeSmuME_2010.vcxproj
@@ -183,6 +183,7 @@
   <ItemGroup>
     <ClCompile Include="..\addons.cpp" />
     <ClCompile Include="..\addons\compactFlash.cpp" />
+    <ClCompile Include="..\addons\expMemory.cpp" />
     <ClCompile Include="..\addons\gbagame.cpp" />
     <ClCompile Include="..\addons\guitarGrip.cpp" />
     <ClCompile Include="..\addons\none.cpp" />
diff --git a/desmume/src/windows/gbaslot_config.cpp b/desmume/src/windows/gbaslot_config.cpp
index 648f86379..776f7bde3 100644
--- a/desmume/src/windows/gbaslot_config.cpp
+++ b/desmume/src/windows/gbaslot_config.cpp
@@ -355,7 +355,9 @@ u32		GBAslot_IDDs[NDS_ADDON_COUNT] = {
 	IDD_GBASLOT_CFLASH,
 	IDD_GBASLOT_RUMBLEPAK,
 	IDD_GBASLOT_GBAGAME,
-	IDD_GBASLOT_GUITARGRIP
+	IDD_GBASLOT_GUITARGRIP,
+	// todo
+	IDD_GBASLOT_NONE
 };
 
 DLGPROC GBAslot_Procs[NDS_ADDON_COUNT] = {
@@ -363,7 +365,9 @@ DLGPROC GBAslot_Procs[NDS_ADDON_COUNT] = {
 	GbaSlotCFlash,
 	GbaSlotRumblePak,
 	GbaSlotGBAgame,
-	GbaSlotGuitarGrip
+	//todo
+	GbaSlotGuitarGrip,
+	GbaSlotNone
 };
 
 
@@ -504,6 +508,8 @@ void GBAslotDialog(HWND hwnd)
 				else
 					needReset = false;
 				break;
+			case NDS_ADDON_EXPMEMORY:
+				break;
 			default:
 				return;
 		}
diff --git a/desmume/src/windows/main.cpp b/desmume/src/windows/main.cpp
index 95710d1b7..d6209dfe7 100644
--- a/desmume/src/windows/main.cpp
+++ b/desmume/src/windows/main.cpp
@@ -1979,6 +1979,8 @@ int _main()
 		break;
 	case NDS_ADDON_GUITARGRIP:
 		break;
+	case NDS_ADDON_EXPMEMORY:
+		break;
 	default:
 		addon_type = NDS_ADDON_NONE;
 		break;