diff --git a/dispatch.h b/dispatch.h
index b7bfb45..c3d1916 100644
--- a/dispatch.h
+++ b/dispatch.h
@@ -500,6 +500,16 @@ DIGEN(0101256, "SNS 15", d_sns);
 DIGEN(0101257, "SNS 16", d_sns);
 DIGEN(0100200, "SMCR", d_smcr);
 DIGEN(0101200, "SMCS", d_smcs);
+DIGEN(0101020, "SS1", d_ssx);
+DIGEN(0100020, "SR1", d_srx);
+DIGEN(0101010, "SS2", d_ssx);
+DIGEN(0100010, "SR2", d_srx);
+DIGEN(0101004, "SS3", d_ssx);
+DIGEN(0100004, "SR3", d_srx);
+DIGEN(0101002, "SS4", d_ssx);
+DIGEN(0100002, "SR4", d_srx);
+DIGEN(0101036, "SSS", d_ssx);
+DIGEN(0100036, "SSR", d_srx);
 
 /* initialize class 3 generics */
 
diff --git a/em.c b/em.c
index b96b825..0506cbb 100755
--- a/em.c
+++ b/em.c
@@ -7421,6 +7421,22 @@ d_sns:  /* 0101240 - 0101257 */
     INCRP;
   goto fetch;
 
+d_ssx:   /* 0101020, 0101010, 0101004, 0101002: SS1-4, SSS */
+  m = (inst & 036) << 11;
+  TRACE(T_FLOW, " SSx\n");
+  RESTRICT();
+  if (sswitch & m)
+    INCRP;
+  goto fetch;
+
+d_srx:   /* 0100020, 0100010, 0100004, 0100002: SR1-4, SRS */
+  m = (inst & 036) << 11;
+  TRACE(T_FLOW, " SRx\n");
+  RESTRICT();
+  if (!(sswitch & m))
+    INCRP;
+  goto fetch;
+
 d_smcr:  /* 0100200 */
   TRACE(T_FLOW, " SMCR\n");
   RESTRICT();