diff --git a/PDP11/pdp11_cpu.c b/PDP11/pdp11_cpu.c
index b0d0209f..88a40bf4 100644
--- a/PDP11/pdp11_cpu.c
+++ b/PDP11/pdp11_cpu.c
@@ -298,7 +298,6 @@ int32 isenable = 0, dsenable = 0;                       /* i, d space flags */
 int32 stop_trap = 1;                                    /* stop on trap */
 int32 stop_vecabort = 1;                                /* stop on vec abort */
 int32 stop_spabort = 1;                                 /* stop on SP abort */
-int32 wait_enable = 0;                                  /* wait state enable */
 int32 autcon_enb = 1;                                   /* autoconfig enable */
 uint32 cpu_model = INIMODEL;                            /* CPU model */
 uint32 cpu_type = 1u << INIMODEL;                       /* model as bit mask */
@@ -574,7 +573,6 @@ REG cpu_reg[] = {
     { BRDATAD (IREQ, int_req, 8, 32, IPL_HLVL, "interrupt pending flags, IPL 0 to 7"), REG_RO },
     { ORDATAD (TRAPS, trap_req, TRAP_V_MAX, "trap pending flags") },
     { FLDATAD (WAIT, wait_state, 0,         "wait state enable flag") },
-    { FLDATA (WAIT_ENABLE, wait_enable, 0), REG_HIDDEN },
     { ORDATAD (STOP_TRAPS, stop_trap, TRAP_V_MAX, "stop on trap flags") },
     { FLDATAD (STOP_VECA, stop_vecabort, 0, "stop on read abort in trap or interrupt") },
     { FLDATAD (STOP_SPA, stop_spabort, 0,   "stop on stack abort in trap or interrupt") },
diff --git a/PDP11/pdp11_cpumod.h b/PDP11/pdp11_cpumod.h
index 3d257754..521922f0 100644
--- a/PDP11/pdp11_cpumod.h
+++ b/PDP11/pdp11_cpumod.h
@@ -48,7 +48,7 @@
 #define PSW_1120        0000377
 
 #define SOP_1123        (BUS_Q|OPT_EIS|OPT_FPP|OPT_MMU|OPT_BVT)
-#define OPT_1123        (OPT_FPP|OPT_CIS|OPT_BVT)
+#define OPT_1123        (OPT_FPP|OPT_CIS|OPT_BVT|OPT_MMU)
 #define PSW_F           0170777
 #define PAR_F           0177777
 #define PDR_F           0077516
diff --git a/PDP11/pdp11_defs.h b/PDP11/pdp11_defs.h
index d5559427..1d41521d 100644
--- a/PDP11/pdp11_defs.h
+++ b/PDP11/pdp11_defs.h
@@ -123,10 +123,10 @@
 #define MOD_1140        8
 #define MOD_1144        9
 #define MOD_1145        10
-#define MOD_1160        11
-#define MOD_1170        12
-#define MOD_1173        13
-#define MOD_1153        14
+#define MOD_1153        11
+#define MOD_1160        12
+#define MOD_1170        13
+#define MOD_1173        14
 #define MOD_1173B       15
 #define MOD_1183        16
 #define MOD_1184        17