--- researchv9/sys/sun3/psl.h	2018/04/24 17:21:59	1.1
+++ researchv9/sys/sun3/psl.h	2018/04/24 17:30:11	1.1.1.2
@@ -21,7 +21,7 @@
 #define	SR_HIGH		0x2700		/* supervisor (interrupt) high pri */
 #define	SR_LOW		0x2000		/* supervisor (interrupt) low pri */
 #define	SR_USER		0x0000		/* user, low priority */
-#define	SR_USERCLR	0xFF00		/* system bits */
+#define	SR_USERCLR	0x7F00		/* system bits */
 #define	SR_TRACE	SR_T1		/* trace mode mask - use T1 (any) */