diff --git a/PDP11/pdp11_cpu.c b/PDP11/pdp11_cpu.c
index a927271e..b0d0209f 100644
--- a/PDP11/pdp11_cpu.c
+++ b/PDP11/pdp11_cpu.c
@@ -623,6 +623,8 @@ MTAB cpu_mod[] = {
     { MTAB_XTD|MTAB_VDV, OPT_FPP, NULL, "NOFPP", &cpu_clr_opt, NULL, NULL, "disable FPP instructions" },
     { MTAB_XTD|MTAB_VDV, OPT_CIS, NULL, "CIS", &cpu_set_opt, NULL, NULL, "enable CIS instructions" },
     { MTAB_XTD|MTAB_VDV, OPT_CIS, NULL, "NOCIS", &cpu_clr_opt, NULL, NULL, "disable CIS instructions" },
+    { MTAB_XTD|MTAB_VDV, OPT_MMU, NULL, "MMU", &cpu_set_opt, NULL, NULL, "enable MMU functionality" },
+    { MTAB_XTD|MTAB_VDV, OPT_MMU, NULL, "NOMMU", &cpu_clr_opt, NULL, NULL, "disable MMU functionality" },
     { MTAB_XTD|MTAB_VDV, OPT_BVT, NULL, "BEVENT", &cpu_set_opt, NULL, NULL, "Enable BEVENT line (11/03, 11/23 only)" },
     { MTAB_XTD|MTAB_VDV, OPT_BVT, NULL, "NOBEVENT", &cpu_clr_opt, NULL, NULL, "Disable BEVENT line (11/03, 11/23 only)" },
     { UNIT_MSIZE, 8192, NULL, "8K", &cpu_set_size, NULL, NULL, "Set memory size to 8Kb"},
diff --git a/PDP11/pdp11_cpumod.h b/PDP11/pdp11_cpumod.h
index da299814..3d257754 100644
--- a/PDP11/pdp11_cpumod.h
+++ b/PDP11/pdp11_cpumod.h
@@ -69,7 +69,7 @@
 #define MM0_1134        0160557
 
 #define SOP_1140        (BUS_U|OPT_EIS|OPT_MMU)
-#define OPT_1140        (OPT_FIS)
+#define OPT_1140        (OPT_FIS|OPT_MMU)
 #define PSW_1140        0170377
 #define PAR_1140        0007777
 #define PDR_1140        0077516
@@ -84,7 +84,7 @@
 #define MM3_1144        0000077
 
 #define SOP_1145        (BUS_U|OPT_EIS|OPT_FPP|OPT_MMU|OPT_RH11)
-#define OPT_1145        (OPT_FPP)
+#define OPT_1145        (OPT_FPP|OPT_MMU)
 #define PSW_1145        0174377
 #define PAR_1145        0007777
 #define PDR_1145        0077717
diff --git a/doc/pdp11_doc.doc b/doc/pdp11_doc.doc
index 095098ab..7bc04b6b 100644
Binary files a/doc/pdp11_doc.doc and b/doc/pdp11_doc.doc differ