diff --git a/PDP10/pdp10_cpu.c b/PDP10/pdp10_cpu.c
index 21098b5e..03af6947 100644
--- a/PDP10/pdp10_cpu.c
+++ b/PDP10/pdp10_cpu.c
@@ -197,7 +197,7 @@ jmp_buf save_env;
 int32 hst_p = 0;                                        /* history pointer */
 int32 hst_lnt = 0;                                      /* history length */
 InstHistory *hst = NULL;                                /* instruction history */
-int32 apr_serial = -1;									/* CPU Serial number */
+int32 apr_serial = -1;                                  /* CPU Serial number */
 
 /* Forward and external declarations */
 
@@ -404,7 +404,7 @@ MTAB cpu_mod[] = {
       NULL, &show_iospace },
     { MTAB_XTD|MTAB_VDV|MTAB_NMO|MTAB_SHP, 0, "HISTORY", "HISTORY",
       &cpu_set_hist, &cpu_show_hist },
-	{ MTAB_XTD|MTAB_VDV|MTAB_VALR, 0, "SERIAL", "SERIAL", &cpu_set_serial, &cpu_show_serial },
+    { MTAB_XTD|MTAB_VDV|MTAB_VALR, 0, "SERIAL", "SERIAL", &cpu_set_serial, &cpu_show_serial },
     { 0 }
     };
 
@@ -2109,14 +2109,14 @@ return;
 
 t_bool aprid (a10 ea, int32 prv)
 {
-	d10 value = (Q_ITS)? UC_AIDITS: UC_AIDDEC;
-	if( (apr_serial == -1) || (!Q_ITS && apr_serial < 4096) )
-		value |= (Q_ITS)? UC_SERITS: UC_SERDEC;
-	else
-		value |= apr_serial;
+  d10 value = (Q_ITS)? UC_AIDITS: UC_AIDDEC;
+  if( (apr_serial == -1) || (!Q_ITS && apr_serial < 4096) )
+    value |= (Q_ITS)? UC_SERITS: UC_SERDEC;
+  else
+    value |= apr_serial;
 
-	Write (ea, value, prv);
-	return FALSE;
+  Write (ea, value, prv);
+  return FALSE;
 }
 
 /* Checked against KS10 ucode */
@@ -2435,29 +2435,29 @@ return SCPE_OK;
 
 t_stat cpu_set_serial (UNIT *uptr, int32 val, char *cptr, void *desc)
 {
-int32 lnt;
-t_stat r;
+  int32 lnt;
+  t_stat r;
 
-if (cptr == NULL) {
+  if (cptr == NULL) {
     apr_serial = -1;
-	return SCPE_OK;
-    }
-lnt = (int32) get_uint (cptr, 10, 077777, &r);
-if ((r != SCPE_OK) || (lnt <= 0) || (!Q_ITS && lnt < 4096))
+    return SCPE_OK;
+  }
+  lnt = (int32) get_uint (cptr, 10, 077777, &r);
+  if ((r != SCPE_OK) || (lnt <= 0) || (!Q_ITS && lnt < 4096))
     return SCPE_ARG;
-apr_serial = lnt & 077777;
-return SCPE_OK;
+  apr_serial = lnt & 077777;
+  return SCPE_OK;
 }
 
 /* Show serial */
 
 t_stat cpu_show_serial (FILE *st, UNIT *uptr, int32 val, void *desc)
 {
-fprintf (st, "Serial: " );
-if( (apr_serial == -1) || (!Q_ITS && apr_serial < 4096) ) {
-	fprintf (st, "%d (default)", (Q_ITS)? UC_SERITS: UC_SERDEC);
-	return SCPE_OK;
-}
-fprintf (st, "%d", apr_serial);
-return SCPE_OK;
+  fprintf (st, "Serial: " );
+  if( (apr_serial == -1) || (!Q_ITS && apr_serial < 4096) ) {
+    fprintf (st, "%d (default)", (Q_ITS)? UC_SERITS: UC_SERDEC);
+    return SCPE_OK;
+  }
+  fprintf (st, "%d", apr_serial);
+  return SCPE_OK;
 }
diff --git a/PDP10/pdp10_lp20.c b/PDP10/pdp10_lp20.c
index 20858e10..f27296ca 100644
--- a/PDP10/pdp10_lp20.c
+++ b/PDP10/pdp10_lp20.c
@@ -25,8 +25,8 @@
 
    lp20         line printer
 
-   29-May-13    TL		Force append when an existing file is attached.  Previously
-						over-wrote file from the top.
+   29-May-13    TL      Force append when an existing file is attached.
+                        Previously over-wrote file from the top.
    19-Jan-07    RMS     Added UNIT_TEXT flag
    04-Sep-05    RMS     Fixed missing return (found by Peter Schorn)
    07-Jul-05    RMS     Removed extraneous externs
@@ -376,17 +376,17 @@ return SCPE_OK;
         else if (paper)
             davfu_action;
         else print_xlate;
-		}
+   }
    else if (paper) {
         if (xlate || delim || delim_hold)
             davfu_action;
         else print_input;
-		}
+   }
    else {
         if (xlate || delim || delim_hold)
             print_xlate;
         else print_input;
-		}
+  }
 */
 
 t_stat lp20_svc (UNIT *uptr)
@@ -660,8 +660,8 @@ t_stat reason;
     
 reason = attach_unit (uptr, cptr);                      /* attach file */
 if (reason == SCPE_OK) {
-	sim_fseek (uptr->fileref, 0, SEEK_END);
-	uptr->pos = ftell (uptr->fileref);
+  sim_fseek (uptr->fileref, 0, SEEK_END);
+  uptr->pos = ftell (uptr->fileref);
 }
 if (lpcsa & CSA_ONL)                                    /* just file chg? */
     return reason;