diff --git a/scp.c b/scp.c
index 04c0905d..1d0146d4 100644
--- a/scp.c
+++ b/scp.c
@@ -2689,7 +2689,7 @@ for (i = 1; i < argc; i++) {                            /* loop thru args */
         if (get_switches (argv[i], &sw, NULL) == SW_ERROR) {
             fprintf (stderr, "Invalid switch %s\n", argv[i]);
             free (targv);
-            return 0;
+            return EXIT_FAILURE;
             }
         sim_switches = sim_switches | sw;
         }
@@ -2697,7 +2697,7 @@ for (i = 1; i < argc; i++) {                            /* loop thru args */
         if ((strlen (argv[i]) + strlen (cbuf) + 3) >= sizeof(cbuf)) {
             fprintf (stderr, "Argument string too long\n");
             free (targv);
-            return 0;
+            return EXIT_FAILURE;
             }
         if (*cbuf)                                      /* concat args */
             strlcat (cbuf, " ", sizeof (cbuf)); 
@@ -2741,6 +2741,7 @@ if (sim_timer_init ()) {
     fprintf (stderr, "Fatal timer initialization error\n");
     if (sim_ttisatty())
         read_line_p ("Hit Return to exit: ", cbuf, sizeof (cbuf) - 1, stdin);
+    free (targv);
     return EXIT_FAILURE;
     }
 sim_register_internal_device (&sim_scp_dev);
@@ -2754,12 +2755,14 @@ if ((stat = sim_ttinit ()) != SCPE_OK) {
         sim_error_text (stat));
     if (sim_ttisatty())
         read_line_p ("Hit Return to exit: ", cbuf, sizeof (cbuf) - 1, stdin);
+    free (targv);
     return EXIT_FAILURE;
     }
 if ((sim_eval = (t_value *) calloc (sim_emax, sizeof (t_value))) == NULL) {
     fprintf (stderr, "Unable to allocate examine buffer\n");
     if (sim_ttisatty())
         read_line_p ("Hit Return to exit: ", cbuf, sizeof (cbuf) - 1, stdin);
+    free (targv);
     return EXIT_FAILURE;
     };
 if (sim_dflt_dev == NULL)                               /* if no default */
@@ -2769,6 +2772,7 @@ if ((stat = reset_all_p (0)) != SCPE_OK) {
         sim_failed_reset_dptr->name, sim_error_text (stat));
     if (sim_ttisatty())
         read_line_p ("Hit Return to exit: ", cbuf, sizeof (cbuf) - 1, stdin);
+    free (targv);
     return EXIT_FAILURE;
     }
 if (register_check) {
@@ -2779,17 +2783,21 @@ if (register_check) {
         sim_printf ("Simulator device register sanity check error\n");
         if (sim_ttisatty())
             read_line_p ("Hit Return to exit: ", cbuf, sizeof (cbuf) - 1, stdin);
+        free (targv);
         return EXIT_FAILURE;
         }
     sim_printf ("*** Good Registers in %s simulator.\n", sim_name);
-    if (argc < 2)                                   /* No remaining command arguments? */
+    if (argc < 2) {                                 /* No remaining command arguments? */
+        free (targv);
         return EXIT_SUCCESS;                        /* then we're done */
+        }
     }
 if ((stat = sim_brk_init ()) != SCPE_OK) {
     fprintf (stderr, "Fatal breakpoint table initialization error\n%s\n",
         sim_error_text (stat));
     if (sim_ttisatty())
         read_line_p ("Hit Return to exit: ", cbuf, sizeof (cbuf) - 1, stdin);
+    free (targv);
     return EXIT_FAILURE;
     }
 /* always check for register definition problems */
@@ -2867,7 +2875,7 @@ return sim_exit_status;
 t_stat process_stdin_commands (t_stat stat, char *argv[], t_bool do_called)
 {
 char cbuf[4*CBUFSIZE], gbuf[CBUFSIZE];
-CONST char *cptr;
+CONST char *cptr = NULL;
 t_stat stat_nomessage;
 CTAB *cmdp = NULL;
 
@@ -4639,12 +4647,12 @@ t_stat assert_cmd (int32 flag, CONST char *cptr)
 char gbuf[CBUFSIZE], gbuf2[CBUFSIZE];
 CONST char *tptr, *gptr;
 REG *rptr;
-uint32 idx;
+uint32 idx = 0;
 t_stat r;
 t_bool Not = FALSE;
 t_bool Exist = FALSE;
 t_bool result;
-t_addr addr;
+t_addr addr = 0;
 t_stat reason;
 
 cptr = (CONST char *)get_sim_opt (CMD_OPT_SW|CMD_OPT_DFT, (CONST char *)cptr, &r);  
@@ -4771,7 +4779,8 @@ else {
                     return SCPE_ARG;
                 gptr = tptr;                                /* update */
                 }
-            else idx = 0;                                   /* not array */
+            else
+                idx = 0;                                    /* not array */
             if (idx >= rptr->depth)                         /* validate subscript */
                 return SCPE_SUB;
             }
@@ -10797,7 +10806,7 @@ SCHTAB *get_asearch (CONST char *cptr, int32 radix, SCHTAB *schptr)
 {
 int32 c, logop, cmpop;
 t_value *logval, *cmpval;
-t_stat reason;
+t_stat reason = SCPE_OK;
 CONST char *ocptr = cptr;
 const char *sptr;
 char gbuf[CBUFSIZE];
@@ -12656,7 +12665,7 @@ return SCPE_OK;
 t_stat sim_exp_check (EXPECT *exp, uint8 data)
 {
 int32 i;
-EXPTAB *ep;
+EXPTAB *ep = NULL;
 int regex_checks = 0;
 char *tstr = NULL;
 
diff --git a/scp.h b/scp.h
index d21f76f3..e446dbf3 100644
--- a/scp.h
+++ b/scp.h
@@ -339,8 +339,8 @@ void sim_debug_unit (uint32 dbits, UNIT* uptr, const char *fmt, ...) GCC_FMT_ATT
 #else
 void _sim_debug_unit (uint32 dbits, UNIT *uptr, const char* fmt, ...) GCC_FMT_ATTR(3, 4);
 void _sim_debug_device (uint32 dbits, DEVICE* dptr, const char* fmt, ...) GCC_FMT_ATTR(3, 4);
-#define sim_debug(dbits, dptr, ...) do { if (sim_deb && dptr && ((dptr)->dctrl & (dbits))) _sim_debug_device (dbits, dptr, __VA_ARGS__);} while (0)
-#define sim_debug_unit(dbits, uptr, ...) do { if (sim_deb && uptr && (((uptr)->dctrl | (uptr)->dptr->dctrl) & (dbits))) _sim_debug_unit (dbits, uptr, __VA_ARGS__);} while (0)
+#define sim_debug(dbits, dptr, ...) do { if ((sim_deb != NULL) && ((dptr) != NULL) && ((dptr)->dctrl & (dbits))) _sim_debug_device (dbits, dptr, __VA_ARGS__);} while (0)
+#define sim_debug_unit(dbits, uptr, ...) do { if ((sim_deb != NULL) && ((uptr) != NULL) && (((uptr)->dctrl | (uptr)->dptr->dctrl) & (dbits))) _sim_debug_unit (dbits, uptr, __VA_ARGS__);} while (0)
 #endif
 void sim_flush_buffered_files (void);
 
diff --git a/sim_console.c b/sim_console.c
index 7b68c573..bf4df38f 100644
--- a/sim_console.c
+++ b/sim_console.c
@@ -2049,7 +2049,7 @@ else
     return sim_messagef (SCPE_INVREM, "Can't enable Remote Console Master mode with Remote Console disabled\n");
 
 if (sim_rem_master_mode) {
-    t_stat stat_nomessage;
+    t_stat stat_nomessage = 0;
 
     sim_messagef (SCPE_OK, "Command input starting on Master Remote Console Session\n");
     stat = sim_run_boot_prep (0);
@@ -2291,7 +2291,7 @@ t_stat sim_set_debon (int32 flag, CONST char *cptr)
 char gbuf[CBUFSIZE];
 t_stat r;
 time_t now;
-size_t buffer_size;
+size_t buffer_size = 0;
 
 if ((cptr == NULL) || (*cptr == 0))                     /* need arg */
     return SCPE_2FARG;
diff --git a/sim_disk.c b/sim_disk.c
index 8f54ba79..d3426c0d 100644
--- a/sim_disk.c
+++ b/sim_disk.c
@@ -1671,7 +1671,6 @@ return SCPE_IOERR;
 
 static t_stat rstsLoadAndScanSATT(rstsContext *context, uint16 uaa, uint16 uar, t_offset *result)
 {
-t_offset blocks = 0;
 uint8 bitmap[8192];
 int i, j;
 RSTS_ACNT acnt;
@@ -2080,6 +2079,7 @@ switch (DK_GET_FMT (uptr)) {                            /* case on format */
 
             /* Construct a pseudo simh disk footer*/
             memcpy (f->Signature, "simh", 4);
+            f->DriveType[sizeof (f->DriveType) - 1] = '\0'; /* Force NUL termination */
             strncpy ((char *)f->DriveType, sim_vhd_disk_get_dtype (uptr->fileref, &f->SectorSize, &f->TransferElementSize, (char *)f->CreatingSimulator, &creation_time), sizeof (f->DriveType) - 1);
             f->SectorSize = NtoHl (f->SectorSize);
             f->TransferElementSize = NtoHl (f->TransferElementSize);
@@ -2146,6 +2146,7 @@ f = (struct simh_disk_footer *)calloc (1, sizeof (*f));
 f->AccessFormat = DK_GET_FMT (uptr);
 total_sectors = (((t_offset)uptr->capac) * ctx->capac_factor * ((dptr->flags & DEV_SECTORS) ? 512 : 1)) / ctx->sector_size;
 memcpy (f->Signature, "simh", 4);
+f->CreatingSimulator[sizeof (f->CreatingSimulator) - 1] = '\0';  /* Force NUL termination */
 strncpy ((char *)f->CreatingSimulator, sim_name, sizeof (f->CreatingSimulator) - 1);
 strncpy ((char *)f->DriveType, dtype, sizeof (f->DriveType) - 1);
 f->SectorSize = NtoHl (ctx->sector_size);
@@ -4736,6 +4737,7 @@ memset (hVHD->Footer.DriveType, '\0', sizeof hVHD->Footer.DriveType);
 memcpy (hVHD->Footer.DriveType, dtype, ((1+strlen (dtype)) < sizeof (hVHD->Footer.DriveType)) ? (1+strlen (dtype)) : sizeof (hVHD->Footer.DriveType));
 hVHD->Footer.DriveSectorSize = NtoHl (SectorSize);
 hVHD->Footer.DriveTransferElementSize = NtoHl (xfer_element_size);
+hVHD->Footer.CreatingSimulator[sizeof (hVHD->Footer.CreatingSimulator) - 1] = '\0';  /* Force NUL termination */
 strncpy ((char *)hVHD->Footer.CreatingSimulator, sim_name, sizeof (hVHD->Footer.CreatingSimulator) - 1);
 hVHD->Footer.Checksum = 0;
 hVHD->Footer.Checksum = NtoHl (CalculateVhdFooterChecksum (&hVHD->Footer, sizeof(hVHD->Footer)));
diff --git a/sim_ether.c b/sim_ether.c
index bad6951c..f9c78686 100644
--- a/sim_ether.c
+++ b/sim_ether.c
@@ -1908,7 +1908,7 @@ static void *
 _eth_writer(void *arg)
 {
 ETH_DEV* volatile dev = (ETH_DEV*)arg;
-ETH_WRITE_REQUEST *request;
+ETH_WRITE_REQUEST *request = NULL;
 
 /* Boost Priority for this I/O thread vs the CPU instruction execution 
    thread which in general won't be readily yielding the processor when 
@@ -4272,7 +4272,6 @@ ETH_MAC filter_address[3] = {
     {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},
   };
 int addr_count;
-ETH_MAC physical_addr = {0x04, 0x05, 0x06, 0x07, 0x08, 0x09};
 ETH_MAC host_nic_phy_hw_addr = {0x02, 0x03, 0x04, 0x05, 0x06, 0x07};
 ETH_MAC *host_phy_addr_list[2] = {&host_nic_phy_hw_addr, NULL};
 int host_phy_addr_listindex;
diff --git a/sim_fio.c b/sim_fio.c
index 8f14eb45..e99799af 100644
--- a/sim_fio.c
+++ b/sim_fio.c
@@ -992,9 +992,7 @@ if (dir) {
 #endif
     t_offset FileSize;
     char *FileName;
-    const char *MatchName = 1 + strrchr (cptr, '/');
-    char *p_name;
-    struct tm *local;
+     char *p_name;
 #if defined (HAVE_GLOB)
     size_t i;
 #endif