diff --git a/3B2/3b2_400_sys.c b/3B2/3b2_400_sys.c
index 9b9ad5df..b6f39a49 100644
--- a/3B2/3b2_400_sys.c
+++ b/3B2/3b2_400_sys.c
@@ -60,7 +60,7 @@ DEVICE *sim_devices[] = {
     NULL
 };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "Reserved Instruction",
     "Breakpoint",
diff --git a/ALTAIR/altair_sys.c b/ALTAIR/altair_sys.c
index daab06bb..34557b1c 100644
--- a/ALTAIR/altair_sys.c
+++ b/ALTAIR/altair_sys.c
@@ -63,7 +63,7 @@ DEVICE *sim_devices[] = {
     NULL
 };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "Unknown I/O Instruction",
     "HALT instruction",
diff --git a/AltairZ80/altairz80_sys.c b/AltairZ80/altairz80_sys.c
index 4279ce20..93706090 100644
--- a/AltairZ80/altairz80_sys.c
+++ b/AltairZ80/altairz80_sys.c
@@ -145,7 +145,7 @@ DEVICE      *sim_devices[]  = {
 
 static char memoryAccessMessage[256];
 static char instructionMessage[256];
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "HALT instruction",
     "Breakpoint",
     memoryAccessMessage,
diff --git a/B5500/b5500_sys.c b/B5500/b5500_sys.c
index acea5c9a..99a5a7c3 100644
--- a/B5500/b5500_sys.c
+++ b/B5500/b5500_sys.c
@@ -76,7 +76,7 @@ DEVICE             *sim_devices[] = {
 };
 
 /* Simulator stop codes */
-const char         *sim_stop_messages[] = {
+const char         *sim_stop_messages[SCPE_BASE] = {
     0,
 };
 
diff --git a/BESM6/besm6_cpu.c b/BESM6/besm6_cpu.c
index b6d0a82e..3e197b65 100644
--- a/BESM6/besm6_cpu.c
+++ b/BESM6/besm6_cpu.c
@@ -284,7 +284,7 @@ DEVICE *sim_devices[] = {
     0
 };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Неизвестная ошибка",                 /* Unknown error */
     "Останов",                            /* STOP */
     "Точка останова",                     /* Emulator breakpoint */
diff --git a/CDC1700/cdc1700_sys.c b/CDC1700/cdc1700_sys.c
index d8157746..1d30c3bb 100644
--- a/CDC1700/cdc1700_sys.c
+++ b/CDC1700/cdc1700_sys.c
@@ -85,7 +85,7 @@ DEVICE *sim_devices[] = {
   NULL
 };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
   "OK",
   "Indirect addressing loop count exceeded",
   "Selective Stop",
diff --git a/GRI/gri_sys.c b/GRI/gri_sys.c
index 75d100be..8c293b9c 100644
--- a/GRI/gri_sys.c
+++ b/GRI/gri_sys.c
@@ -67,7 +67,7 @@ DEVICE *sim_devices[] = {
     NULL
     };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "Unimplemented unit",
     "HALT instruction",
diff --git a/H316/h316_sys.c b/H316/h316_sys.c
index f988a7f3..d8c91280 100644
--- a/H316/h316_sys.c
+++ b/H316/h316_sys.c
@@ -88,7 +88,7 @@ DEVICE *sim_devices[] = {
     NULL
     };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "Unimplemented instruction",
     "Unimplemented I/O device",
diff --git a/HP2100/hp2100_sys.c b/HP2100/hp2100_sys.c
index 66f32fc1..d966c5b3 100644
--- a/HP2100/hp2100_sys.c
+++ b/HP2100/hp2100_sys.c
@@ -1968,7 +1968,7 @@ DEVICE *sim_devices [] = {                      /* an array of pointers to the s
 #define DEVICE_COUNT        (sizeof sim_devices / sizeof sim_devices [0] - 1)   /* the count excludes the NULL pointer */
 
 
-const char *sim_stop_messages [] = {            /* an array of pointers to the stop messages in STOP_nnn order */
+const char *sim_stop_messages [SCPE_BASE] = {   /* an array of pointers to the stop messages in STOP_nnn order */
     "Impossible error",                         /*   0 (never returned) */
     "Unimplemented instruction",                /*   STOP_UNIMPL */
     "Unassigned select code",                   /*   STOP_UNSC */
diff --git a/HP3000/hp3000_sys.c b/HP3000/hp3000_sys.c
index 769d28ca..465b393f 100644
--- a/HP3000/hp3000_sys.c
+++ b/HP3000/hp3000_sys.c
@@ -1099,7 +1099,7 @@ DEVICE *sim_devices [] = {                      /* an array of pointers to the s
 #define DEVICE_COUNT        (sizeof sim_devices / sizeof sim_devices [0] - 1)
 
 
-const char *sim_stop_messages [] = {            /* an array of pointers to the stop messages in STOP_nnn order */
+const char *sim_stop_messages [SCPE_BASE] = {   /* an array of pointers to the stop messages in STOP_nnn order */
     "Impossible error",                         /*   0 (never returned) */
     "System halt",                              /*   STOP_SYSHALT */
     "Unimplemented instruction",                /*   STOP_UNIMPL */
diff --git a/I1401/i1401_sys.c b/I1401/i1401_sys.c
index 7bf1b4bf..ba9e58c7 100644
--- a/I1401/i1401_sys.c
+++ b/I1401/i1401_sys.c
@@ -84,7 +84,7 @@ DEVICE *sim_devices[] = {
     NULL
     };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "Unimplemented instruction",
     "Non-existent memory",
diff --git a/I1620/i1620_sys.c b/I1620/i1620_sys.c
index 2dc91c49..5ab3061b 100644
--- a/I1620/i1620_sys.c
+++ b/I1620/i1620_sys.c
@@ -70,7 +70,7 @@ DEVICE *sim_devices[] = {
     NULL
     };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "HALT instruction",
     "Breakpoint",
diff --git a/I650/i650_sys.c b/I650/i650_sys.c
index b9ddc3bd..3f2c18a2 100644
--- a/I650/i650_sys.c
+++ b/I650/i650_sys.c
@@ -58,7 +58,7 @@ DIB  mt_dib  = { 5, &mt_cmd, &mt_ini };
 DIB  dsk_dib = { 4, &mt_cmd, &dsk_ini };
 
 /* Simulator stop codes */
-const char         *sim_stop_messages[] = {
+const char         *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "HALT instruction",
     "Breakpoint",
diff --git a/I7000/i7010_sys.c b/I7000/i7010_sys.c
index f8995582..e91f8df0 100644
--- a/I7000/i7010_sys.c
+++ b/I7000/i7010_sys.c
@@ -115,7 +115,7 @@ DIB  com_dib = { CH_TYP_79XX|CH_TYP_UREC, 0, 04200, 07700, &com_cmd, NULL };
 
 
 /* Simulator stop codes */
-const char         *sim_stop_messages[] = {
+const char         *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "IO device not ready",
     "HALT instruction",
diff --git a/I7000/i701_sys.c b/I7000/i701_sys.c
index acdfe48d..0b3eb24c 100644
--- a/I7000/i701_sys.c
+++ b/I7000/i701_sys.c
@@ -82,7 +82,7 @@ DIB   mt_dib = { CH_TYP_PIO, NUM_UNITS_MT, 0400, 07770, &mt_cmd, &mt_ini };
 
 
 /* Simulator stop codes */
-const char         *sim_stop_messages[] = {
+const char         *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "IO device not ready",
     "HALT instruction",
diff --git a/I7000/i7070_sys.c b/I7000/i7070_sys.c
index d485af3c..a9bc6226 100644
--- a/I7000/i7070_sys.c
+++ b/I7000/i7070_sys.c
@@ -116,7 +116,7 @@ DIB  com_dib = { CH_TYP_79XX, 0, 0, 0, &com_cmd, NULL };
 #endif
 
 /* Simulator stop codes */
-const char         *sim_stop_messages[] = {
+const char         *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "IO device not ready",
     "HALT instruction",
diff --git a/I7000/i7080_sys.c b/I7000/i7080_sys.c
index c27d9981..4e0c8cea 100644
--- a/I7000/i7080_sys.c
+++ b/I7000/i7080_sys.c
@@ -130,7 +130,7 @@ DIB  com_dib = { CH_TYP_79XX, 0, 0, 0, &com_cmd, NULL };
 #endif
 
 /* Simulator stop codes */
-const char         *sim_stop_messages[] = {
+const char         *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "IO device not ready",
     "HALT instruction",
diff --git a/I7000/i7090_sys.c b/I7000/i7090_sys.c
index 76b82078..87fa2831 100644
--- a/I7000/i7090_sys.c
+++ b/I7000/i7090_sys.c
@@ -143,7 +143,7 @@ DIB  hsdrm_dib = { CH_TYP_SPEC, 1, 0330, 0777, &hsdrm_cmd, &hsdrm_ini };
 
 
 /* Simulator stop codes */
-const char         *sim_stop_messages[] = {
+const char         *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "IO device not ready",
     "HALT instruction",
diff --git a/I7094/i7094_sys.c b/I7094/i7094_sys.c
index f109d768..8827cc89 100644
--- a/I7094/i7094_sys.c
+++ b/I7094/i7094_sys.c
@@ -95,7 +95,7 @@ DEVICE *sim_devices[] = {
 
 char ch_bkpt_msg[] = "Channel A breakpoint, CLC: xxxxxx";
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "HALT instruction",
     "Breakpoint",
diff --git a/Ibm1130/ibm1130_sys.c b/Ibm1130/ibm1130_sys.c
index 46636b5a..5c18f60a 100644
--- a/Ibm1130/ibm1130_sys.c
+++ b/Ibm1130/ibm1130_sys.c
@@ -71,7 +71,7 @@ DEVICE *sim_devices[] = {
     NULL
 };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "Wait",
     "Invalid command", 
diff --git a/Intel-Systems/ibmpc/ibmpc_sys.c b/Intel-Systems/ibmpc/ibmpc_sys.c
index a5a1c1e1..9915941b 100644
--- a/Intel-Systems/ibmpc/ibmpc_sys.c
+++ b/Intel-Systems/ibmpc/ibmpc_sys.c
@@ -85,7 +85,7 @@ DEVICE *sim_devices[] = {
     NULL
 };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "Unknown I/O Instruction",
     "HALT instruction",
diff --git a/Intel-Systems/ibmpcxt/ibmpcxt_sys.c b/Intel-Systems/ibmpcxt/ibmpcxt_sys.c
index 819dc83f..fbd1c659 100644
--- a/Intel-Systems/ibmpcxt/ibmpcxt_sys.c
+++ b/Intel-Systems/ibmpcxt/ibmpcxt_sys.c
@@ -85,7 +85,7 @@ DEVICE *sim_devices[] = {
     NULL
 };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "Unknown I/O Instruction",
     "HALT instruction",
diff --git a/Interdata/id16_sys.c b/Interdata/id16_sys.c
index dc781d2d..9b7e8aac 100644
--- a/Interdata/id16_sys.c
+++ b/Interdata/id16_sys.c
@@ -86,7 +86,7 @@ DEVICE *sim_devices[] = {
     NULL
     };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "Reserved instruction",
     "HALT instruction",
diff --git a/Interdata/id32_sys.c b/Interdata/id32_sys.c
index 98ee4ed7..e2fe7545 100644
--- a/Interdata/id32_sys.c
+++ b/Interdata/id32_sys.c
@@ -90,7 +90,7 @@ DEVICE *sim_devices[] = {
     NULL
     };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "Reserved instruction",
     "HALT instruction",
diff --git a/LGP/lgp_sys.c b/LGP/lgp_sys.c
index 3762b071..49932da1 100644
--- a/LGP/lgp_sys.c
+++ b/LGP/lgp_sys.c
@@ -66,7 +66,7 @@ DEVICE *sim_devices[] = {
     NULL
     };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "STOP",
     "Breakpoint",
diff --git a/NOVA/nova_sys.c b/NOVA/nova_sys.c
index bfc65cd8..54ec8ff1 100644
--- a/NOVA/nova_sys.c
+++ b/NOVA/nova_sys.c
@@ -125,7 +125,7 @@ DEVICE *sim_devices[] = {
     NULL
     };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "Unknown I/O instruction",
     "HALT instruction",
diff --git a/PDP1/pdp1_sys.c b/PDP1/pdp1_sys.c
index c78cd41e..0c3a2dcf 100644
--- a/PDP1/pdp1_sys.c
+++ b/PDP1/pdp1_sys.c
@@ -103,7 +103,7 @@ DEVICE *sim_devices[] = {
     NULL
     };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "Undefined instruction",
     "HALT instruction",
diff --git a/PDP10/kx10_sys.c b/PDP10/kx10_sys.c
index 7e11df05..04b16095 100644
--- a/PDP10/kx10_sys.c
+++ b/PDP10/kx10_sys.c
@@ -215,7 +215,7 @@ DEVICE *sim_devices[] = {
     NULL
     };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "HALT instruction",
     "Breakpoint",
diff --git a/PDP10/pdp10_sys.c b/PDP10/pdp10_sys.c
index f063cde9..fb79b25d 100644
--- a/PDP10/pdp10_sys.c
+++ b/PDP10/pdp10_sys.c
@@ -104,7 +104,7 @@ DEVICE *sim_devices[] = {
     NULL
     };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "HALT instruction",
     "Breakpoint",
diff --git a/PDP11/pdp11_sys.c b/PDP11/pdp11_sys.c
index 59dc65d6..de89c6c1 100644
--- a/PDP11/pdp11_sys.c
+++ b/PDP11/pdp11_sys.c
@@ -218,7 +218,7 @@ DEVICE *sim_devices[] = {
     NULL
     };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "Red stack trap",
     "Odd address trap",
diff --git a/PDP18B/pdp18b_sys.c b/PDP18B/pdp18b_sys.c
index a4b01321..07b40db9 100644
--- a/PDP18B/pdp18b_sys.c
+++ b/PDP18B/pdp18b_sys.c
@@ -194,7 +194,7 @@ DEVICE *sim_devices[] = {
     NULL
     };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "Undefined instruction",
     "HALT instruction",
diff --git a/PDP8/pdp8_sys.c b/PDP8/pdp8_sys.c
index 5ac4deba..ae2eae20 100644
--- a/PDP8/pdp8_sys.c
+++ b/PDP8/pdp8_sys.c
@@ -115,7 +115,7 @@ DEVICE *sim_devices[] = {
     NULL
     };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "Unimplemented instruction",
     "HALT instruction",
diff --git a/PDQ-3/pdq3_sys.c b/PDQ-3/pdq3_sys.c
index 390c5eb8..e2825271 100644
--- a/PDQ-3/pdq3_sys.c
+++ b/PDQ-3/pdq3_sys.c
@@ -69,7 +69,7 @@ DEVICE *sim_devices[] = {
     &tim_dev,
     NULL
     };
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
   "---",
   "PC Breakpoint",
   "MEM Breakpoint",
diff --git a/S3/s3_sys.c b/S3/s3_sys.c
index 50f58ff5..878de1d9 100644
--- a/S3/s3_sys.c
+++ b/S3/s3_sys.c
@@ -79,7 +79,7 @@ DEVICE *sim_devices[] = {
     NULL
 };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "Unknown I/O Instruction",
     "HALT instruction",
diff --git a/SAGE/m68k_sys.c b/SAGE/m68k_sys.c
index d0702d8d..b090ddf0 100644
--- a/SAGE/m68k_sys.c
+++ b/SAGE/m68k_sys.c
@@ -272,7 +272,7 @@ t_stat sim_load(FILE* fptr, CONST char* cptr, CONST char* fnam, t_bool flag)
     return SCPE_OK;
 }
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "---",
     "PC Breakpoint",
     "MEM Breakpoint",
diff --git a/SDS/sds_sys.c b/SDS/sds_sys.c
index 5184bc0c..41a4f6fb 100644
--- a/SDS/sds_sys.c
+++ b/SDS/sds_sys.c
@@ -83,7 +83,7 @@ DEVICE *sim_devices[] = {
     NULL
     };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "IO device not ready",
     "HALT instruction",
diff --git a/SSEM/ssem_sys.c b/SSEM/ssem_sys.c
index a3a115d8..bae39945 100644
--- a/SSEM/ssem_sys.c
+++ b/SSEM/ssem_sys.c
@@ -64,7 +64,7 @@ DEVICE *sim_devices[] = {
     NULL
     };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "Stop",
     "Breakpoint",
diff --git a/TX-0/tx0_sys.c b/TX-0/tx0_sys.c
index b015545a..823ca7f0 100644
--- a/TX-0/tx0_sys.c
+++ b/TX-0/tx0_sys.c
@@ -90,7 +90,7 @@ DEVICE *sim_devices[] = {
     NULL
     };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "Undefined instruction",
     "HALT instruction",
diff --git a/VAX/vax_sys.c b/VAX/vax_sys.c
index ea0d4d24..01473ed2 100644
--- a/VAX/vax_sys.c
+++ b/VAX/vax_sys.c
@@ -86,7 +86,7 @@ REG *sim_PC = &cpu_reg[0];
 
 int32 sim_emax = 60;
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "HALT instruction",
     "Breakpoint",
diff --git a/alpha/alpha_sys.c b/alpha/alpha_sys.c
index 622bd532..7eb7e5aa 100644
--- a/alpha/alpha_sys.c
+++ b/alpha/alpha_sys.c
@@ -53,7 +53,7 @@ REG *sim_PC = &cpu_reg[0];
 
 int32 sim_emax = 1;
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "HALT instruction",
     "Breakpoint",
diff --git a/doc/simh.doc b/doc/simh.doc
index 371182ce..f999ffd5 100644
Binary files a/doc/simh.doc and b/doc/simh.doc differ
diff --git a/imlac/imlac_sys.c b/imlac/imlac_sys.c
index 2003569e..4c002c32 100644
--- a/imlac/imlac_sys.c
+++ b/imlac/imlac_sys.c
@@ -53,7 +53,7 @@ DEVICE *sim_devices[] = {
   NULL
 };
   
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
   "Unknown error",
   "HALT instruction",
   "Breakpoint",
diff --git a/sigma/sigma_sys.c b/sigma/sigma_sys.c
index 95f5e8d2..5a8ac96e 100644
--- a/sigma/sigma_sys.c
+++ b/sigma/sigma_sys.c
@@ -96,7 +96,7 @@ DEVICE *sim_devices[] = {
     NULL
     };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "Invalid I/O configuration",
     "Breakpoint",
diff --git a/sim_defs.h b/sim_defs.h
index 30c0cb1c..a97492e5 100644
--- a/sim_defs.h
+++ b/sim_defs.h
@@ -93,7 +93,8 @@
         sim_devices[]           array of pointers to simulated devices
         sim_PC                  pointer to saved PC register descriptor
         sim_interval            simulator interval to next event
-        sim_stop_messages[]     array of pointers to stop messages
+        sim_stop_messages[SCPE_BASE]     
+                                array of pointers to stop messages
         sim_instr()             instruction execution routine
         sim_load()              binary loader routine
         sim_emax                maximum number of words in an instruction
diff --git a/swtp6800/swtp6800/mp-a2_sys.c b/swtp6800/swtp6800/mp-a2_sys.c
index adcd79f5..f5e95129 100644
--- a/swtp6800/swtp6800/mp-a2_sys.c
+++ b/swtp6800/swtp6800/mp-a2_sys.c
@@ -75,7 +75,7 @@ DEVICE *sim_devices[] = {
     NULL
 };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "Unknown I/O Instruction",
     "HALT instruction",
diff --git a/swtp6800/swtp6800/mp-a_sys.c b/swtp6800/swtp6800/mp-a_sys.c
index cfbc9814..cac0a98f 100644
--- a/swtp6800/swtp6800/mp-a_sys.c
+++ b/swtp6800/swtp6800/mp-a_sys.c
@@ -73,7 +73,7 @@ DEVICE *sim_devices[] = {
     NULL
 };
 
-const char *sim_stop_messages[] = {
+const char *sim_stop_messages[SCPE_BASE] = {
     "Unknown error",
     "Unknown I/O Instruction",
     "HALT instruction",