anchor.diff:  %% New in R13B
   % Wide characters (Unicode)
   io_request({put_chars,Encoding,Chars}, Port) -> % Binary new in R9C
  -    put_chars(wrap_characters_to_binary(Chars,Encoding,
  -					case get(unicode) of 
  -					    true -> unicode;
  -					    _ -> latin1
  -					end), Port);
  +    put_chars(wrap_characters_to_binary(Chars, Encoding, get(encoding)), Port);
   io_request({put_chars,Encoding,Mod,Func,Args}, Port) ->
       Result = case catch apply(Mod,Func,Args) of
   		 Data when is_list(Data); is_binary(Data) ->
  -		     wrap_characters_to_binary(Data,Encoding,
  -					       case get(unicode) of 
  -						   true -> unicode;
  -						   _ -> latin1
  -					       end);
  +		     wrap_characters_to_binary(Data, Encoding, get(encoding));
   		 Undef ->
   		     Undef
   	     end,
  
positive.code:     end.
  
  %% setopts
  setopts(Opts0,Port) ->
      Opts = proplists:unfold(
  	     proplists:substitute_negations(
  	       [{latin1,unicode}], 
  	       Opts0)),
      case check_valid_opts(Opts) of
  	true ->
  	    do_setopts(Opts,Port);
  	false ->
  	    {error,{error,enotsup}}
      end.
  check_valid_opts([]) ->
      true;
  check_valid_opts([{unicode,Valid}|T]) when Valid =:= true; Valid =:= utf8; Valid =:= false ->
      check_valid_opts(T);
  check_valid_opts(_) ->
      false.
  
  do_setopts(Opts, _Port) ->
      case proplists:get_value(unicode,Opts) of
  	Valid when Valid =:= true; Valid =:= utf8 ->
  	    put(unicode,true);
  	false ->
  	    put(unicode,false);
  	undefined ->
  	    ok
      end,
      {ok,ok}.
  
  getopts(_Port) ->
      Uni = {unicode, get(unicode) =:= true},
      {ok,[Uni]}.
  
  wrap_characters_to_binary(Chars,From,To) ->
  
negative.code: 	_ ->
  	    {error,{error,enotsup}}
      end;
  io_request(getopts, _Port) ->
      getopts();
  io_request({setopts,Opts}, _Port) when is_list(Opts) ->
      setopts(Opts);
  io_request({requests,Reqs}, Port) ->
      io_requests(Reqs, {ok,ok}, Port);
  io_request(R, _Port) ->                      %Unknown request
  