--- a/scripts/control/sysupdate.m
+++ b/scripts/control/sysupdate.m
@@ -1,20 +1,20 @@
-# Copyright (C) 1996 Auburn University.  All Rights Reserved
-#
-# This file is part of Octave. 
-#
-# Octave is free software; you can redistribute it and/or modify it 
-# under the terms of the GNU General Public License as published by the 
-# Free Software Foundation; either version 2, or (at your option) any 
-# later version. 
-# 
-# Octave is distributed in the hope that it will be useful, but WITHOUT 
-# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 
-# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License 
-# for more details.
-# 
-# You should have received a copy of the GNU General Public License 
-# along with Octave; see the file COPYING.  If not, write to the Free 
-# Software Foundation, 59 Temple Place, Suite 330, Boston, MA 0211
+## Copyright (C) 1996 Auburn University.  All Rights Reserved
+##
+## This file is part of Octave. 
+##
+## Octave is free software; you can redistribute it and/or modify it 
+## under the terms of the GNU General Public License as published by the 
+## Free Software Foundation; either version 2, or (at your option) any 
+## later version. 
+## 
+## Octave is distributed in the hope that it will be useful, but WITHOUT 
+## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 
+## FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License 
+## for more details.
+## 
+## You should have received a copy of the GNU General Public License 
+## along with Octave; see the file COPYING.  If not, write to the Free 
+## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 0211
 
 ## -*- texinfo -*-
 ## @deftypefn {Function File } { @var{sys} =} sysupdate ( @var{sys}, @var{opt} ) 
@@ -49,9 +49,10 @@
 ## See also: tf2sys, ss2sys, zp2sys, sysout, sys2ss, sys2tf, sys2zp
 
 function sys = sysupdate(sys,opt)
-# Written by John Ingram  7-9-96
 
-  # check for correct number of inputs 
+  ## Written by John Ingram  7-9-96
+
+  ## check for correct number of inputs 
   if (nargin != 2)
     usage("newsys = sysupdate(sys,opt)");
   elseif(! is_struct(sys) )
@@ -61,22 +62,22 @@
     error("2nd argument must be \"tf\", \"zp\", \"ss\", or \"all\"");
   endif
 
-  # check to make sure not trying to make a SISO system out of a MIMO sys
+  ## check to make sure not trying to make a SISO system out of a MIMO sys
   if ( (strcmp(opt,"tf") + strcmp(opt,"zp") + strcmp(opt,"all")) ...
 	& strcmp(sysgettype(sys),"ss") &  (! is_siso(sys) ) )
     error("MIMO -> SISO update requested");
   endif
 
-  # update transfer function if desired
+  ## update transfer function if desired
   if ( (strcmp(opt, "tf") + strcmp(opt,"all"))&&  (!sys.sys(2)))
-    # check to make sure the system is not discrete and continuous
+    ## check to make sure the system is not discrete and continuous
     is_digital(sys);
 
-    # if original system zero-pole
+    ## if original system zero-pole
     if strcmp(sysgettype(sys),"zp")
       [sys.num,sys.den] = zp2tf(sys.zer,sys.pol,sys.k);
       sys.sys(2) = 1;
-    # if original system is state-space
+    ## if original system is state-space
     elseif(sys.sys(1) == 2)
       [sys.num,sys.den] = ss2tf(sys.a,sys.b,sys.c,sys.d);
       sys.sys(2) = 1; 
@@ -84,16 +85,16 @@
   endif
 
 
-  # update zero-pole if desired
+  ## update zero-pole if desired
   if ( (strcmp(opt, "zp") + strcmp(opt,"all")) && (! sys.sys(3)) )
-    # check to make sure the system is not discrete and continuous
+    ## check to make sure the system is not discrete and continuous
     is_digital(sys);
 
-    # original system is transfer function
+    ## original system is transfer function
     if (sys.sys(1) == 0)
       [sys.zer,sys.pol,sys.k] = tf2zp(sys.num,sys.den);
       sys.sys(3) = 1;
-    # original system is state-space
+    ## original system is state-space
 
     elseif(sys.sys(1) == 2)
       [sys.zer,sys.pol,sys.k] = ss2zp(sys.a,sys.b,sys.c,sys.d);
@@ -102,19 +103,19 @@
 
   endif
 
-  # update state-space if desired
+  ## update state-space if desired
   if ( (strcmp(opt, "ss") + strcmp(opt,"all")) && (! sys.sys(4)) )
-    # original system is transfer function
+    ## original system is transfer function
     if (sys.sys(1) == 0)
       [sys.a,sys.b,sys.c,sys.d] = tf2ss(sys.num,sys.den);
       sys.sys(4) = 1;
-    # original system is zero-pole
+    ## original system is zero-pole
     elseif(sys.sys(1) == 1)
       [sys.a,sys.b,sys.c,sys.d] = zp2ss(sys.zer,sys.pol,sys.k);
       sys.sys(4) = 1; 
     endif
 
-    # create new state names
+    ## create new state names
     sys.stname = sysdefstname(sys.n, sys.nz);
   endif