diff --git a/Assets/dll/gpgx.wbx.zst b/Assets/dll/gpgx.wbx.zst
index 81bff2bcf7..b454cab96f 100644
Binary files a/Assets/dll/gpgx.wbx.zst and b/Assets/dll/gpgx.wbx.zst differ
diff --git a/src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/GPGX.IDebuggable.cs b/src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/GPGX.IDebuggable.cs
index b5cc096e8a..06215aabbf 100644
--- a/src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/GPGX.IDebuggable.cs
+++ b/src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/GPGX.IDebuggable.cs
@@ -1,4 +1,4 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
 using System.Runtime.InteropServices;
 
 using BizHawk.Common;
@@ -72,28 +72,28 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.gpgx
 
 		private void InitMemCallbacks()
 		{
-			ExecCallback = a =>
+			ExecCallback = (addr, val) =>
 			{
 				if (MemoryCallbacks.HasExecutes)
 				{
 					const uint flags = (uint)MemoryCallbackFlags.AccessExecute;
-					MemoryCallbacks.CallMemoryCallbacks(a, 0, flags, "M68K BUS");
+					MemoryCallbacks.CallMemoryCallbacks(addr, val, flags, "M68K BUS");
 				}
 			};
-			ReadCallback = a =>
+			ReadCallback = (addr, val) =>
 			{
 				if (MemoryCallbacks.HasReads)
 				{
 					const uint flags = (uint)MemoryCallbackFlags.AccessRead;
-					MemoryCallbacks.CallMemoryCallbacks(a, 0, flags, "M68K BUS");
+					MemoryCallbacks.CallMemoryCallbacks(addr, val, flags, "M68K BUS");
 				}
 			};
-			WriteCallback = a =>
+			WriteCallback = (addr, val) =>
 			{
 				if (MemoryCallbacks.HasWrites)
 				{
 					const uint flags = (uint)MemoryCallbackFlags.AccessWrite;
-					MemoryCallbacks.CallMemoryCallbacks(a, 0, flags, "M68K BUS");
+					MemoryCallbacks.CallMemoryCallbacks(addr, val, flags, "M68K BUS");
 				}
 			};
 			_memoryCallbacks.ActiveChanged += RefreshMemCallbacks;
diff --git a/src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/LibGPGX.cs b/src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/LibGPGX.cs
index 473a542535..50b6873177 100644
--- a/src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/LibGPGX.cs
+++ b/src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/LibGPGX.cs
@@ -194,7 +194,7 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.gpgx
 		public abstract void gpgx_set_input_callback(input_cb cb);
 
 		[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
-		public delegate void mem_cb(uint addr);
+		public delegate void mem_cb(uint addr, uint value); //value MUST be uint, since the value will be trimmed if the type is byte (8-bit) or ushort (16-bit) and the value read/written/executed is bigger than that (i.e 32 bits).
 
 		[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
 		public delegate void CDCallback(int addr, CDLog_AddrType addrtype, CDLog_Flags flags);
diff --git a/waterbox/gpgx/cinterface/callbacks.h b/waterbox/gpgx/cinterface/callbacks.h
index 4ee2e5ee78..3d3ec5f5f5 100644
--- a/waterbox/gpgx/cinterface/callbacks.h
+++ b/waterbox/gpgx/cinterface/callbacks.h
@@ -7,9 +7,9 @@
 
 typedef ECL_ENTRY void (*CDCallback)(int32 addr, int32 addrtype, int32 flags);
 
-extern ECL_ENTRY void (*biz_execcb)(unsigned addr);
-extern ECL_ENTRY void (*biz_readcb)(unsigned addr);
-extern ECL_ENTRY void (*biz_writecb)(unsigned addr);
+extern ECL_ENTRY void (*biz_execcb)(unsigned addr, unsigned value);
+extern ECL_ENTRY void (*biz_readcb)(unsigned addr, unsigned value);
+extern ECL_ENTRY void (*biz_writecb)(unsigned addr, unsigned value);
 extern CDCallback biz_cdcb;
 
 extern ECL_ENTRY void (*cdd_readcallback)(int lba, void *dest, int subcode);
diff --git a/waterbox/gpgx/cinterface/cinterface.c b/waterbox/gpgx/cinterface/cinterface.c
index 2fae99f0a6..fef76bb88e 100644
--- a/waterbox/gpgx/cinterface/cinterface.c
+++ b/waterbox/gpgx/cinterface/cinterface.c
@@ -61,9 +61,9 @@ static uint8_t brm_format[0x40] =
 	0x52,0x41,0x4d,0x5f,0x43,0x41,0x52,0x54,0x52,0x49,0x44,0x47,0x45,0x5f,0x5f,0x5f
 };
 
-ECL_ENTRY void (*biz_execcb)(unsigned addr);
-ECL_ENTRY void (*biz_readcb)(unsigned addr);
-ECL_ENTRY void (*biz_writecb)(unsigned addr);
+ECL_ENTRY void (*biz_execcb)(unsigned addr, unsigned int value);
+ECL_ENTRY void (*biz_readcb)(unsigned addr, unsigned int value);
+ECL_ENTRY void (*biz_writecb)(unsigned addr, unsigned int value);
 CDCallback biz_cdcb = NULL;
 ECL_ENTRY void (*cdd_readcallback)(int lba, void *dest, int subcode);
 uint8 *tempsram;
@@ -790,7 +790,7 @@ void bk_cpu_hook(hook_type_t type, int width, unsigned int address, unsigned int
 		case HOOK_M68K_E:
 		{
 			if (biz_execcb)
-				biz_execcb(address);
+				biz_execcb(address, value);
 
 			if (biz_cdcb)
 			{
@@ -804,7 +804,7 @@ void bk_cpu_hook(hook_type_t type, int width, unsigned int address, unsigned int
 		case HOOK_M68K_R:
 		{
 			if (biz_readcb)
-				biz_readcb(address);
+				biz_readcb(address, value);
 
 			break;
 		}
@@ -812,7 +812,7 @@ void bk_cpu_hook(hook_type_t type, int width, unsigned int address, unsigned int
 		case HOOK_M68K_W:
 		{
 			if (biz_writecb)
-				biz_writecb(address);
+				biz_writecb(address, value);
 
 			break;
 		}
@@ -1035,7 +1035,7 @@ GPGX_EX void gpgx_reset(int hard)
 		gen_reset(0);
 }
 
-GPGX_EX void gpgx_set_mem_callback(ECL_ENTRY void (*read)(unsigned), ECL_ENTRY void (*write)(unsigned), ECL_ENTRY void (*exec)(unsigned))
+GPGX_EX void gpgx_set_mem_callback(ECL_ENTRY void (*read)(unsigned, unsigned), ECL_ENTRY void (*write)(unsigned, unsigned), ECL_ENTRY void (*exec)(unsigned, unsigned))
 {
 	biz_readcb = read;
 	biz_writecb = write;