diff --git a/sys/arch/x68k/x68k/locore.s b/sys/arch/x68k/x68k/locore.s
index 27fc56d048be..f492a2f0f4a6 100644
--- a/sys/arch/x68k/x68k/locore.s
+++ b/sys/arch/x68k/x68k/locore.s
@@ -1,4 +1,4 @@
-/*	$NetBSD: locore.s,v 1.3 1996/05/29 17:19:07 oki Exp $	*/
+/*	$NetBSD: locore.s,v 1.4 1996/07/16 16:18:34 oki Exp $	*/
 
 /*
  * Copyright (c) 1988 University of Utah.
@@ -188,18 +188,39 @@ Lbe10:
 	cmpw	#12,d0			| address error vector?
 	jeq	Lisaerr			| yes, go to it
 	movl	d1,a0			| fault address
-	ptestr	#1,a0@,#7		| do a table search
+	movl	sp@,d0			| function code from ssw
+	btst	#8,d0			| data fault?
+	jne	Lbe10a
+	movql	#1,d0			| user program access FC
+					| (we dont separate data/program)
+	btst	#5,a1@			| supervisor mode?
+	jeq	Lbe10a			| if no, done
+	movql	#5,d0			| else supervisor program access
+Lbe10a:
+	ptestr	d0,a0@,#7		| do a table search
 	pmove	psr,sp@			| save result
-	btst	#7,sp@			| bus error bit set?
-	jeq	Lismerr			| no, must be MMU fault
-	clrw	sp@			| yes, re-clear pad word
-	jra	Lisberr			| and process as normal bus error
+	movb	sp@,d1
+	btst	#2,d1			| invalid? (incl. limit viol and berr)
+	jeq	Lmightnotbemerr		| no -> wp check
+	btst	#7,d1			| is it MMU table berr?
+	jeq	Lismerr			| no, must be fast
+	jra	Lisberr1		| real bus err needs not be fast
+Lmightnotbemerr:
+	btst	#3,d1			| write protect bit set?
+	jeq	Lisberr1		| no, must be bus error
+	movl	sp@,d0			| ssw into low word of d0
+	andw	#0xc0,d0		| write protect is set on page:
+	cmpw	#0x40,d0		| was it read cycle?
+	jeq	Lisberr1		| yes, was not WPE, must be bus err
+	jra	Lismerr			| no, must be mem err
 Lismerr:
 	movl	#T_MMUFLT,sp@-		| show that we are an MMU fault
 	jra	Ltrapnstkadj		| and deal with it
 Lisaerr:
 	movl	#T_ADDRERR,sp@-		| mark address error
 	jra	Ltrapnstkadj		| and deal with it
+Lisberr1:
+	clrw	sp@			| re-clear pad word
 Lisberr:
 	movl	#T_BUSERR,sp@-		| mark bus error
 Ltrapnstkadj: