diff --git a/BaS_gcc/include/interrupts.h b/BaS_gcc/include/interrupts.h
index daee737..e6e0d8d 100644
--- a/BaS_gcc/include/interrupts.h
+++ b/BaS_gcc/include/interrupts.h
@@ -101,7 +101,7 @@ extern int register_interrupt_handler(uint8_t source, uint8_t level, uint8_t pri
 #define ISR_USER_ISR 	0x02
 
 extern void isr_init(void);
-extern int isr_register_handler(int type, int vector, int (*handler)(void *, void *), void *hdev, void *harg);
-extern void isr_remove_handler(int type ,int (*handler)(void *, void *));
+extern int isr_register_handler(int vector, int (*handler)(void *, void *), void *hdev, void *harg);
+extern void isr_remove_handler(int (*handler)(void *, void *));
 extern bool isr_execute_handler(int vector);
 #endif /* _INTERRUPTS_H_ */
diff --git a/BaS_gcc/net/net_timer.c b/BaS_gcc/net/net_timer.c
index 7fa6ced..4601ad8 100644
--- a/BaS_gcc/net/net_timer.c
+++ b/BaS_gcc/net/net_timer.c
@@ -152,8 +152,7 @@ bool timer_init(uint8_t ch, uint8_t lvl, uint8_t pri)
 	/*
 	 * Register the timer interrupt handler
 	 */
-	if (!isr_register_handler(ISR_DBUG_ISR, 
-				TIMER_VECTOR(ch), 
+	if (!isr_register_handler(TIMER_VECTOR(ch), 
 				(int (*)(void *,void *)) timer_default_isr,
 				NULL, 
 				(void *) &net_timer[ch])
diff --git a/BaS_gcc/sys/BaS.c b/BaS_gcc/sys/BaS.c
index eb02d1e..73db9cf 100644
--- a/BaS_gcc/sys/BaS.c
+++ b/BaS_gcc/sys/BaS.c
@@ -264,7 +264,7 @@ void network_init(void)
 
 	isr_init();		/* need to call that explicitely, otherwise isr table might be full */
 
-	if (!isr_register_handler(ISR_DBUG_ISR, vector, handler, NULL, (void *) &nif1))
+	if (!isr_register_handler(vector, handler, NULL, (void *) &nif1))
 	{
 		dbg("%s: unable to register handler for vector %d\r\n", __FUNCTION__, vector);
 		return;
@@ -276,7 +276,7 @@ void network_init(void)
     handler = dma_interrupt_handler;
     vector = 112;
 
-    if (!isr_register_handler(ISR_DBUG_ISR, vector, handler, NULL,NULL))
+    if (!isr_register_handler(vector, handler, NULL,NULL))
 	{
 		dbg("%s: Error: Unable to register handler for vector %s\r\n", __FUNCTION__, vector);
 		return;
diff --git a/BaS_gcc/sys/interrupts.c b/BaS_gcc/sys/interrupts.c
index 8ed1fdb..e7e06cf 100644
--- a/BaS_gcc/sys/interrupts.c
+++ b/BaS_gcc/sys/interrupts.c
@@ -88,31 +88,29 @@ int register_interrupt_handler(uint8_t source, uint8_t level, uint8_t priority,
 	return 0;
 }
 
-#ifndef UIF_MAX_ISR_ENTRY
-#define UIF_MAX_ISR_ENTRY   (20)
+#ifndef MAX_ISR_ENTRY
+#define MAX_ISR_ENTRY   (20)
 #endif
 
 
 typedef struct
 {
 	int     vector;
-	int     type;
 	int     (*handler)(void *, void *);
 	void    *hdev;
 	void    *harg;
 } ISRENTRY;
 
-ISRENTRY isrtab[UIF_MAX_ISR_ENTRY];
+ISRENTRY isrtab[MAX_ISR_ENTRY];
 
 
 void isr_init(void)
 {
 	int index;
 
-	for (index = 0; index < UIF_MAX_ISR_ENTRY; index++)
+	for (index = 0; index < MAX_ISR_ENTRY; index++)
 	{
 		isrtab[index].vector = 0;
-		isrtab[index].type = 0;
 		isrtab[index].handler = 0;
 		isrtab[index].hdev = 0;
 		isrtab[index].harg = 0;
@@ -120,8 +118,7 @@ void isr_init(void)
 }
 
 
-int isr_register_handler(int type, int vector, 
-		int (*handler)(void *, void *), void *hdev, void *harg)
+int isr_register_handler(int vector, int (*handler)(void *, void *), void *hdev, void *harg)
 {
 	/*
 	 * This function places an interrupt handler in the ISR table,
@@ -133,28 +130,24 @@ int isr_register_handler(int type, int vector,
 	 */
 	int index;
 
-	if ((vector == 0) || 
-			((type != ISR_DBUG_ISR) && (type != ISR_USER_ISR)) ||
-			(handler == NULL))
+	if ((vector == 0) || (handler == NULL))
 	{
-		dbg("%s: illegal type, vector or handler!\r\n", __FUNCTION__);
+		dbg("%s: illegal vector or handler!\r\n", __FUNCTION__);
 		return false;
 	}
 
-	for (index = 0; index < UIF_MAX_ISR_ENTRY; index++)
+	for (index = 0; index < MAX_ISR_ENTRY; index++)
 	{
-		if ((isrtab[index].vector == vector) &&
-				(isrtab[index].type == type))
+		if (isrtab[index].vector == vector) 
 		{
-			/* only one entry of each type per vector */
-			dbg("%s: already set handler with this type and vector (%d, %d)\r\n", __FUNCTION__, type, vector);
+			/* one cross each, only! */
+			dbg("%s: already set handler with this vector (%d, %d)\r\n", __FUNCTION__, vector);
 			return false;
 		}
 
 		if (isrtab[index].vector == 0)
 		{
 			isrtab[index].vector = vector;
-			isrtab[index].type = type;
 			isrtab[index].handler = handler;
 			isrtab[index].hdev = hdev;
 			isrtab[index].harg = harg;
@@ -167,21 +160,19 @@ int isr_register_handler(int type, int vector,
 	return false;   /* no available slots */
 }
 
-void isr_remove_handler(int type, int (*handler)(void *, void *))
+void isr_remove_handler(int (*handler)(void *, void *))
 {
 	/*
 	 * This routine removes from the ISR table all
-	 * entries that matches 'type' and 'handler'.
+	 * entries that matches 'handler'.
 	 */
 	int index;
 
-	for (index = 0; index < UIF_MAX_ISR_ENTRY; index++)
+	for (index = 0; index < MAX_ISR_ENTRY; index++)
 	{
-		if ((isrtab[index].handler == handler) && 
-				(isrtab[index].type == type))
+		if (isrtab[index].handler == handler) 
 		{
 			isrtab[index].vector = 0;
-			isrtab[index].type = 0;
 			isrtab[index].handler = 0;
 			isrtab[index].hdev = 0;
 			isrtab[index].harg = 0;
@@ -189,7 +180,7 @@ void isr_remove_handler(int type, int (*handler)(void *, void *))
 			return;
 		}
 	}
-	dbg("%s: no such handler registered (type=%d, handler=%p\r\n", __FUNCTION__, type, handler);
+	dbg("%s: no such handler registered (handler=%p\r\n", __FUNCTION__, handler);
 }
 
 
@@ -205,10 +196,9 @@ bool isr_execute_handler(int vector)
 	/*
 	 * First locate a BaS Interrupt Service Routine handler.
 	 */
-	for (index = 0; index < UIF_MAX_ISR_ENTRY; index++)
+	for (index = 0; index < MAX_ISR_ENTRY; index++)
 	{
-		if ((isrtab[index].vector == vector) &&
-				(isrtab[index].type == ISR_DBUG_ISR))
+		if (isrtab[index].vector == vector) 
 		{
 			retval = true;
 		
diff --git a/BaS_gcc/sys/mmu.c b/BaS_gcc/sys/mmu.c
index 3689606..602133b 100644
--- a/BaS_gcc/sys/mmu.c
+++ b/BaS_gcc/sys/mmu.c
@@ -407,6 +407,9 @@ bool access_exception(uint32_t pc, uint32_t format_status)
 	extern uint8_t _FASTRAM_END[];
 	uint32_t FASTRAM_END = (uint32_t) &_FASTRAM_END[0];
 
+	/*
+	 * extract fault status from format_status exception stack field
+	 */
 	fault_status = (((format_status & 0xc000000) >> 24) |
 					((format_status & 0x30000) >> 16));