diff --git a/src/burn/drv/megadrive/megadrive.cpp b/src/burn/drv/megadrive/megadrive.cpp
index 0dd25608f..fd0fb0b5c 100644
--- a/src/burn/drv/megadrive/megadrive.cpp
+++ b/src/burn/drv/megadrive/megadrive.cpp
@@ -2941,6 +2941,11 @@ static void MegadriveSetupSRAM()
 	}
 }
 
+static INT32 __fastcall MegadriveTAScallback(void)
+{
+	return 0; // disable
+}
+
 INT32 MegadriveInit()
 {
 	Mem = NULL;
@@ -2992,6 +2997,7 @@ INT32 MegadriveInit()
 		SekSetWriteWordHandler(4, MegadriveIOWriteWord);
 
 		SekSetIrqCallback( MegadriveIrqCallback );
+		SekSetTASCallback(MegadriveTAScallback);
 		SekClose();
 	}
 	
diff --git a/src/cpu/m68000_intf.cpp b/src/cpu/m68000_intf.cpp
index c70691fc7..94fca5727 100644
--- a/src/cpu/m68000_intf.cpp
+++ b/src/cpu/m68000_intf.cpp
@@ -761,6 +761,15 @@ extern "C" void M68KcmpildCallback(UINT32 val, INT32 reg)
 		pSekExt->CmpCallback(val, reg);
 	}
 }
+
+extern "C" INT32 M68KTASCallback()
+{
+	if (pSekExt->TASCallback) {
+		return pSekExt->TASCallback();
+	}
+	
+	return 1; // enable by default
+}
 #endif
 
 // ----------------------------------------------------------------------------
@@ -1602,6 +1611,18 @@ INT32 SekSetCmpCallback(pSekCmpCallback pCallback)
 	return 0;
 }
 
+INT32 SekSetTASCallback(pSekTASCallback pCallback)
+{
+#if defined FBA_DEBUG
+	if (!DebugCPU_SekInitted) bprintf(PRINT_ERROR, _T("SekSetTASCallback called without init\n"));
+	if (nSekActive == -1) bprintf(PRINT_ERROR, _T("SekSetTASCallback called when no CPU open\n"));
+#endif
+
+	pSekExt->TASCallback = pCallback;
+
+	return 0;
+}
+
 // Set handlers
 INT32 SekSetReadByteHandler(INT32 i, pSekReadByteHandler pHandler)
 {
@@ -1981,6 +2002,7 @@ struct m68ki_cpu_core_pointerblock
 	void (*pc_changed_callback)(unsigned int new_pc); /* Called when the PC changes by a large amount */
 	void (*set_fc_callback)(unsigned int new_fc);     /* Called when the CPU function code changes */
 	void (*instr_hook_callback)(void);                /* Called every instruction cycle prior to execution */
+	int  (*tas_instr_callback)(void);                 /* Called when a TAS instruction is encountered */
 };
 
 
diff --git a/src/cpu/m68000_intf.h b/src/cpu/m68000_intf.h
index 9e4b0f42a..1c183eee3 100644
--- a/src/cpu/m68000_intf.h
+++ b/src/cpu/m68000_intf.h
@@ -75,6 +75,7 @@ typedef INT32 (__fastcall *pSekResetCallback)();
 typedef INT32 (__fastcall *pSekRTECallback)();
 typedef INT32 (__fastcall *pSekIrqCallback)(INT32 irq);
 typedef INT32 (__fastcall *pSekCmpCallback)(UINT32 val, INT32 reg);
+typedef INT32 (__fastcall *pSekTASCallback)();
 
 extern INT32 nSekCycles[SEK_MAX], nSekCPUType[SEK_MAX];
 
@@ -96,6 +97,7 @@ struct SekExt {
 	pSekRTECallback RTECallback;
 	pSekIrqCallback IrqCallback;
 	pSekCmpCallback CmpCallback;
+	pSekTASCallback TASCallback;
 };
 
 #define SEK_DEF_READ_WORD(i, a) { UINT16 d; d = (UINT16)(pSekExt->ReadByte[i](a) << 8); d |= (UINT16)(pSekExt->ReadByte[i]((a) + 1)); return d; }
@@ -226,6 +228,7 @@ INT32 SekSetResetCallback(pSekResetCallback pCallback);
 INT32 SekSetRTECallback(pSekRTECallback pCallback);
 INT32 SekSetIrqCallback(pSekIrqCallback pCallback);
 INT32 SekSetCmpCallback(pSekCmpCallback pCallback);
+INT32 SekSetTASCallback(pSekTASCallback pCallback);
 
 // Get a CPU's PC
 UINT32 SekGetPC(INT32 n);
diff --git a/src/cpu/m68k/m68kconf.h b/src/cpu/m68k/m68kconf.h
index ad7187c31..b0d4bcb76 100644
--- a/src/cpu/m68k/m68kconf.h
+++ b/src/cpu/m68k/m68kconf.h
@@ -126,8 +126,8 @@
 /* If ON, CPU will call the callback when it encounters a tas
  * instruction.
  */
-#define M68K_TAS_HAS_CALLBACK       OPT_ON
-#define M68K_TAS_CALLBACK()         your_tas_handler_function()
+#define M68K_TAS_HAS_CALLBACK       OPT_SPECIFY_HANDLER
+#define M68K_TAS_CALLBACK()         M68KTASCallback()
 
 
 /* If ON, CPU will call the set fc callback on every memory access to
@@ -217,6 +217,7 @@ void M68KResetCallback(void);
 int M68KIRQAcknowledge(int nIRQ);
 void M68KRTECallback(void);
 void M68KcmpildCallback(unsigned int val, int reg);
+int M68KTASCallback(void);
 
 unsigned int __fastcall M68KFetchByte(unsigned int a);
 unsigned int __fastcall M68KFetchWord(unsigned int a);