diff --git a/H316/h316_cpu.c b/H316/h316_cpu.c
index 4dd6cc4a..c3d440fc 100644
--- a/H316/h316_cpu.c
+++ b/H316/h316_cpu.c
@@ -1,6 +1,6 @@
 /* h316_cpu.c: Honeywell 316/516 CPU simulator
 
-   Copyright (c) 1999-2015, Robert M. Supnik
+   Copyright (c) 1999-2017, Robert M. Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -25,6 +25,7 @@
 
    cpu          H316/H516 CPU
 
+   07-Sep-17    RMS     Fixed sim_eval declaration in history routine (COVERITY)
    21-May-13    RLA     Add IMP/TIP support
                         Move SMK/OTK instructions here (from CLK)
                         Make SET CPU DMA work as documented
@@ -1757,7 +1758,7 @@ t_stat cpu_show_hist (FILE *st, UNIT *uptr, int32 val, void *desc)
 {
 int32 cr, k, di, op, lnt;
 char *cptr = (char *) desc;
-t_value sim_eval;
+extern t_value *sim_eval;
 t_stat r;
 InstHistory *h;
 static uint8 has_opnd[16] = {
@@ -1786,8 +1787,8 @@ for (k = 0; k < lnt; k++) {                             /* print specified */
         if (h->pc & HIST_EA)
             fprintf (st, "%05o  ", h->ea);
         else fprintf (st, "       ");
-        sim_eval = h->ir;
-        if ((fprint_sym (st, h->pc & X_AMASK, &sim_eval,
+        sim_eval[0] = h->ir;
+        if ((fprint_sym (st, h->pc & X_AMASK, sim_eval,
             &cpu_unit, SWMASK ('M'))) > 0)
             fprintf (st, "(undefined) %06o", h->ir);
         op = I_GETOP (h->ir) & 017;                     /* base op */
diff --git a/I7094/i7094_cpu.c b/I7094/i7094_cpu.c
index 64c406db..f466f78b 100644
--- a/I7094/i7094_cpu.c
+++ b/I7094/i7094_cpu.c
@@ -1,6 +1,6 @@
 /* i7094_cpu.c: IBM 7094 CPU simulator
 
-   Copyright (c) 2003-2011, Robert M. Supnik
+   Copyright (c) 2003-2017, Robert M. Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -25,6 +25,7 @@
 
    cpu          7094 central processor
 
+   07-Sep-17    RMS     Fixed sim_eval declaration in history routine (COVERITY)
    31-Dec-11    RMS     Select traps have priority over protect traps
                         Added SRI, SPI
                         Fixed user mode and relocation from CTSS RPQ documentation
@@ -2400,9 +2401,9 @@ t_stat cpu_fprint_one_inst (FILE *st, uint32 pc, uint32 rpt, uint32 ea,
     t_uint64 ir, t_uint64 ac, t_uint64 mq, t_uint64 si, t_uint64 opnd)
 {
 int32 ch;
-t_value sim_eval;
+extern t_value *sim_eval;
 
-sim_eval = ir;
+sim_eval[0] = ir;
 if (pc & HIST_PC) {                                     /* instruction? */
     fputs ("CPU ", st);
     fprintf (st, "%05o ", (int)(pc & AMASK));
@@ -2420,7 +2421,7 @@ if (pc & HIST_PC) {                                     /* instruction? */
     if (ir & INST_T_DEC)
         fprintf (st, "       ");
     else fprintf (st, "%05o  ", ea);
-    if (fprint_sym (st, pc & AMASK, &sim_eval, &cpu_unit, SWMASK ('M')) > 0) {
+    if (fprint_sym (st, pc & AMASK, sim_eval, &cpu_unit, SWMASK ('M')) > 0) {
         fputs ("(undefined) ", st);
         fprint_val (st, ir, 8, 36, PV_RZRO);
         }
@@ -2436,7 +2437,7 @@ else if ((ch = HIST_CH (pc))) {                         /* channel? */
     fprintf (st, "%05o  ", (int)(pc & AMASK));
     fputs ("                                              ", st);
     fprintf (st, "%05o  ", (int)(ea & AMASK));
-    if (fprint_sym (st, pc & AMASK, &sim_eval, &cpu_unit,
+    if (fprint_sym (st, pc & AMASK, sim_eval, &cpu_unit,
         (ch_dev[ch - 1].flags & DEV_7909)? SWMASK ('N'): SWMASK ('I')) > 0) {
         fputs ("(undefined) ", st);
         fprint_val (st, ir, 8, 36, PV_RZRO);
diff --git a/NOVA/nova_cpu.c b/NOVA/nova_cpu.c
index 16b83b15..05c63ab9 100644
--- a/NOVA/nova_cpu.c
+++ b/NOVA/nova_cpu.c
@@ -1,6 +1,6 @@
 /* nova_cpu.c: NOVA CPU simulator
 
-   Copyright (c) 1993-2013, Robert M. Supnik
+   Copyright (c) 1993-2017, Robert M. Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -25,6 +25,7 @@
 
    cpu          Nova central processor
 
+   07-Sep-17    RMS     Fixed sim_eval declaration in history routine (COVERITY)
    17-Mar-13    RMS     Added clarifying brances to IND_STEP macro (Dave Bryan)
    04-Jul-07    BKR     DEV_SET/CLR macros now used,
                         support for non-existant devices added
@@ -1372,7 +1373,7 @@ return ( SCPE_OK ) ;
 
 int hist_fprintf( FILE * fp, int itemNum, Hist_entry * hptr )
 {
-t_value     sim_eval ;
+extern t_value *sim_eval ;
 
 if ( hptr )
     {
@@ -1394,8 +1395,8 @@ if ( hptr )
         fprintf( fp, "%06o  %06o   ", SP, FP ) ;
         }
 
-    sim_eval = (hptr->ir & 0xFFFF) ;
-    if ( (fprint_sym(fp, (hptr->pc & AMASK), &sim_eval, &cpu_unit, SWMASK ('M'))) > 0 )
+    sim_eval[0] = (hptr->ir & 0xFFFF) ;
+    if ( (fprint_sym(fp, (hptr->pc & AMASK), sim_eval, &cpu_unit, SWMASK ('M'))) > 0 )
         {
         fprintf( fp, "(undefined) %04o", (hptr->ir & 0xFFFF) ) ;
     }
diff --git a/PDP1/pdp1_cpu.c b/PDP1/pdp1_cpu.c
index 7e52241c..03ffc81e 100644
--- a/PDP1/pdp1_cpu.c
+++ b/PDP1/pdp1_cpu.c
@@ -1,6 +1,6 @@
 /* pdp1_cpu.c: PDP-1 CPU simulator
 
-   Copyright (c) 1993-2015, Robert M. Supnik
+   Copyright (c) 1993-2017, Robert M. Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -25,6 +25,7 @@
 
    cpu          PDP-1 central processor
 
+   07-Sep-17    RMS     Fixed sim_eval declaration in history routine (COVERITY)
    27-Mar-15    RMS     Backported changes from GitHub master
    21-Mar-12    RMS     Fixed & vs && in Ea_ch (Michael Bloom)
    30-May-07    RMS     Fixed typo in SBS clear (Norm Lastovica)
@@ -1665,7 +1666,7 @@ t_stat cpu_show_hist (FILE *st, UNIT *uptr, int32 val, void *desc)
 int32 ov, pf, op, k, di, lnt;
 char *cptr = (char *) desc;
 t_stat r;
-t_value sim_eval;
+extern t_value *sim_eval;
 InstHistory *h;
 
 if (hst_lnt == 0)                                       /* enabled? */
@@ -1691,8 +1692,8 @@ for (k = 0; k < lnt; k++) {                             /* print specified */
         if ((op < 032) && (op != 007))                  /* mem ref instr */
             fprintf (st, "%06o  ", h->ea);
         else fprintf (st, "        ");
-        sim_eval = h->ir;
-        if ((fprint_sym (st, h->pc & AMASK, &sim_eval, &cpu_unit, SWMASK ('M'))) > 0)
+        sim_eval[0] = h->ir;
+        if ((fprint_sym (st, h->pc & AMASK, sim_eval, &cpu_unit, SWMASK ('M'))) > 0)
             fprintf (st, "(undefined) %06o", h->ir);
         else if (op < 030)                              /* mem ref instr */
             fprintf (st, " [%06o]", h->opnd);
diff --git a/PDP10/pdp10_cpu.c b/PDP10/pdp10_cpu.c
index 37f0c1d0..98d63c91 100644
--- a/PDP10/pdp10_cpu.c
+++ b/PDP10/pdp10_cpu.c
@@ -25,6 +25,7 @@
 
    cpu          KS10 central processor
 
+   07-Sep-17    RMS     Fixed sim_eval declaration in history routine (COVERITY)
    14-Jan-17    RMS     Fixed bugs in 1-proceed
    09-Feb-16    RMS     Fixed nested indirects and executes (Tim Litt)
    25-Mar-12    RMS     Added missing parameters to prototypes (Mark Pizzolato)
@@ -2478,7 +2479,7 @@ t_stat cpu_show_hist (FILE *st, UNIT *uptr, int32 val, void *desc)
 int32 k, di, lnt;
 char *cptr = (char *) desc;
 t_stat r;
-t_value sim_eval;
+extern t_value *sim_eval;
 InstHistory *h;
 
 if (hst_lnt == 0)                                       /* enabled? */
@@ -2500,8 +2501,8 @@ for (k = 0; k < lnt; k++) {                             /* print specified */
         fprint_val (st, h->ac, 8, 36, PV_RZRO);
         fputs ("  ", st);
         fprintf (st, "%06o  ", h->ea);
-        sim_eval = h->ir;
-        if ((fprint_sym (st, h->pc & AMASK, &sim_eval, &cpu_unit, SWMASK ('M'))) > 0) {
+        sim_eval[0] = h->ir;
+        if ((fprint_sym (st, h->pc & AMASK, sim_eval, &cpu_unit, SWMASK ('M'))) > 0) {
             fputs ("(undefined) ", st);
             fprint_val (st, h->ir, 8, 36, PV_RZRO);
             }
diff --git a/PDP8/pdp8_cpu.c b/PDP8/pdp8_cpu.c
index 8c6808a6..ee681dc4 100644
--- a/PDP8/pdp8_cpu.c
+++ b/PDP8/pdp8_cpu.c
@@ -25,6 +25,7 @@
 
    cpu          central processor
 
+   07-Sep-17    RMS     Fixed sim_eval declaration in history routine (COVERITY)
    09-Mar-17    RMS     Fixed PCQ_ENTRY for interrupts (COVERITY)
    13-Feb-17    RMS     RESET clear L'AC, per schematics
    28-Jan-17    RMS     Renamed switch register variable to SR, per request
@@ -1576,7 +1577,7 @@ t_stat cpu_show_hist (FILE *st, UNIT *uptr, int32 val, void *desc)
 int32 l, k, di, lnt;
 char *cptr = (char *) desc;
 t_stat r;
-t_value sim_eval;
+extern t_value *sim_eval;
 InstHistory *h;
 
 if (hst_lnt == 0)                                       /* enabled? */
@@ -1599,8 +1600,8 @@ for (k = 0; k < lnt; k++) {                             /* print specified */
         if (h->ir < 06000)
             fprintf (st, "%05o  ", h->ea);
         else fprintf (st, "       ");
-        sim_eval = h->ir;
-        if ((fprint_sym (st, h->pc & ADDRMASK, &sim_eval, &cpu_unit, SWMASK ('M'))) > 0)
+        sim_eval[0] = h->ir;
+        if ((fprint_sym (st, h->pc & ADDRMASK, sim_eval, &cpu_unit, SWMASK ('M'))) > 0)
             fprintf (st, "(undefined) %04o", h->ir);
         if (h->ir < 04000)
             fprintf (st, "  [%04o]", h->opnd);
diff --git a/SDS/sds_cpu.c b/SDS/sds_cpu.c
index f8c8f6ed..8acda63e 100644
--- a/SDS/sds_cpu.c
+++ b/SDS/sds_cpu.c
@@ -26,6 +26,7 @@
    cpu          central processor
    rtc          real time clock
 
+   07-Sep-17    RMS     Fixed sim_eval declaration in history routine (COVERITY)
    09-Mar-17    RMS     trap_P not set if mem mgt trap during fetch (COVERITY)
    28-Apr-07    RMS     Removed clock initialization
    29-Dec-06    RMS     Fixed breakpoint variable declarations
@@ -1746,7 +1747,7 @@ t_stat cpu_show_hist (FILE *st, UNIT *uptr, int32 val, void *desc)
 int32 ov, k, di, lnt;
 char *cptr = (char *) desc;
 t_stat r;
-t_value sim_eval;
+extern t_value *sim_eval;
 InstHistory *h;
 static char *cyc[] = { "   ", "   ", "INT", "TRP" };
 static char *modes = "NMU?";
@@ -1772,8 +1773,8 @@ for (k = 0; k < lnt; k++) {                             /* print specified */
         if (h->ea & HIST_NOEA)
             fprintf (st, "      ");
         else fprintf (st, "%05o ", h->ea);
-        sim_eval = h->ir;
-        if ((fprint_sym (st, h->pc, &sim_eval, &cpu_unit, SWMASK ('M'))) > 0)
+        sim_eval[0] = h->ir;
+        if ((fprint_sym (st, h->pc, sim_eval, &cpu_unit, SWMASK ('M'))) > 0)
             fprintf (st, "(undefined) %08o", h->ir);
         fputc ('\n', st);                               /* end line */
         }                                               /* end else instruction */