diff --git a/I1620/i1620_cd.c b/I1620/i1620_cd.c
index 5f539300..d16847e4 100644
--- a/I1620/i1620_cd.c
+++ b/I1620/i1620_cd.c
@@ -350,7 +350,7 @@ if (feof (cdr_unit.fileref))                            /* eof? */
     return STOP_NOCD;
 if (ferror (cdr_unit.fileref)) {                        /* error? */
     ind[IN_RDCHK] = 1;                                  /* set read check */
-    sim_printf ("CDR I/O error: %s", strerror (errno));
+    sim_perror ("CDR I/O error");
     clearerr (cdr_unit.fileref);
     return SCPE_IOERR;
     }
@@ -533,7 +533,7 @@ fputs (cdp_buf, cdp_unit.fileref);                      /* write card */
 cdp_unit.pos = ftell (cdp_unit.fileref);                /* count char */
 if (ferror (cdp_unit.fileref)) {                        /* error? */
     ind[IN_WRCHK] = 1;
-    sim_printf ("CDR I/O error: %s", strerror (errno));
+    sim_perror ("CDR I/O error");
     clearerr (cdp_unit.fileref);
     return SCPE_IOERR;
     }
diff --git a/I1620/i1620_lp.c b/I1620/i1620_lp.c
index aedc55ca..0ff48ad8 100644
--- a/I1620/i1620_lp.c
+++ b/I1620/i1620_lp.c
@@ -264,7 +264,7 @@ if (lpt_bptr) {                                         /* any line? */
     lpt_buf_init ();                                    /* reinit buf */
     if (ferror (lpt_unit.fileref)) {                    /* error? */
         ind[IN_PRCHK] = ind[IN_WRCHK] = 1;              /* wr, pri check */
-        sim_printf ("LPT I/O error: %s", strerror (errno));
+        sim_perror ("LPT I/O error");
         clearerr (lpt_unit.fileref);
         return SCPE_IOERR;
         }
@@ -315,7 +315,7 @@ ind[IN_PRCH9] = CHP (9, cct[cct_ptr]) != 0;             /* set indicators */
 ind[IN_PRCH12] = CHP (12, cct[cct_ptr]) != 0;
 if (ferror (lpt_unit.fileref)) {                        /* error? */
     ind[IN_PRCHK] = ind[IN_WRCHK] = 1;                  /* wr, pri check */
-    sim_printf ("LPT I/O error: %s", strerror (errno));
+    sim_perror ("LPT I/O error");
     clearerr (lpt_unit.fileref);
     return SCPE_IOERR;
     }
diff --git a/I1620/i1620_pt.c b/I1620/i1620_pt.c
index 935d0ac2..e7d3eef3 100644
--- a/I1620/i1620_pt.c
+++ b/I1620/i1620_pt.c
@@ -334,7 +334,7 @@ do {
         if (feof (ptr_unit.fileref))
             sim_printf ("PTR end of file\n");
         else
-            sim_printf ("PTR I/O error: %s", strerror (errno));
+            sim_perror ("PTR I/O error");;
         clearerr (ptr_unit.fileref);
         return SCPE_IOERR;
         }
@@ -490,7 +490,7 @@ if ((ptp_unit.flags & UNIT_ATT) == 0) {                 /* attached? */
     }
 if (putc (c, ptp_unit.fileref) == EOF) {                /* write char */
     ind[IN_WRCHK] = 1;                                  /* error? */
-    sim_printf ("PTP I/O error: %s", strerror (errno));
+    sim_perror ("PTP I/O error");
     clearerr (ptp_unit.fileref);
     return SCPE_IOERR;
     }
diff --git a/scp.c b/scp.c
index fb5f1074..751f0839 100644
--- a/scp.c
+++ b/scp.c
@@ -9583,7 +9583,10 @@ if (buf != stackbuf)
 
 void sim_perror (const char *msg)
 {
-sim_printf ("%s: %s\n", msg, strerror (errno));
+int saved_errno = errno;
+
+perror (msg);
+sim_printf ("%s: %s\n", msg, strerror (saved_errno));
 }
 
 /* Print command result message to stdout, sim_log (if enabled) and sim_deb (if enabled) */
diff --git a/sim_disk.c b/sim_disk.c
index 584984ea..7b960a63 100644
--- a/sim_disk.c
+++ b/sim_disk.c
@@ -1349,13 +1349,16 @@ return SCPE_OK;
 
 t_stat sim_disk_perror (UNIT *uptr, const char *msg)
 {
+int saved_errno = errno;
+
 if (!(uptr->flags & UNIT_ATTABLE))                      /* not attachable? */
     return SCPE_NOATT;
 switch (DK_GET_FMT (uptr)) {                            /* case on format */
     case DKUF_F_STD:                                    /* SIMH format */
     case DKUF_F_VHD:                                    /* VHD format */
     case DKUF_F_RAW:                                    /* Raw Physical Disk Access */
-        sim_printf ("%s %s: %s\n", sim_uname(uptr), msg, strerror(errno));
+        perror (msg);
+        sim_printf ("%s %s: %s\n", sim_uname(uptr), msg, strerror(saved_errno));
     default:
         ;
     }