diff --git a/tools/3dump b/tools/3dump
index dfbf321..4ac6301 100755
--- a/tools/3dump
+++ b/tools/3dump
@@ -17,9 +17,9 @@ while (1) {
   my $word= (($b1 & 077) << 12) | (($b2 & 077) << 6) | ($b3 & 077);
 
   my $c1= ($word >> 9) & 0777;
-  $c1= ($c1 < 0200) ? chr($c1) : " ";
+  $c1= (($c1 >= 32) && ($c1 <= 126)) ? chr($c1) : ' ';
   my $c2= $word & 0777;
-  $c2= ($c2 < 0200) ? chr($c2) : " ";
+  $c2= (($c2 >= 32) && ($c2 <= 126)) ? chr($c2) : ' ';
   printf("%06o %s%s\n", $word, $c1, $c2)
 }
 close($IN);
diff --git a/tools/a7out b/tools/a7out
index b5af073..0e33615 100755
--- a/tools/a7out
+++ b/tools/a7out
@@ -1301,8 +1301,8 @@ sub word2ascii {
     my $c1     = ( $word >> 9 ) & 0177;
     my $c2     = $word & 0177;
     my $result = "";
-    $result .= chr($c1) if ($c1);
-    $result .= chr($c2) if ($c2);
+    $result .= (($c1 >= 32) && ($c1 <= 126)) ? chr($c1) : ' ';
+    $result .= (($c2 >= 32) && ($c2 <= 126)) ? chr($c2) : ' ';
     return ($result);
 }