RFC 135 (rfc135) - Page 2 of 3

Response to NWG/RFC 110

RFC 135                 Response to NWG/RFC #110           29 April 1971


      character escape        [2]
      character delete        backspace
      system delete           [2]$
      line delete             [2]# or [2]#NL
      logical line end        [2];
      line continuation       [2]NL
      ASCII control           [2]@

   The option in "line delete" is to allow the user to enter a new line
   (NL) immediately after the "line delete" to line up margins without
   entering a null line; to enter a null line after a "line delete"
   would require two NL characters.

   The two new functions defined above, "line continuation" and "ASCII
   control," are used as follows.  The "line continuation" is used to
   enter a line which is longer than the 2741 carriage (or the margin
   placement) will permit.  It can be looked on as the complement of the
   "logical line end" in that is allows you to enter one logical line on
   several physical lines.

   The use of the "ASCII control" function requires some background.
   There are of course many characters in ASCII which are keyed as
   combinations of "control" and another key.  The "character escape"
   function may be used to handle these control characters as follows: a
   "character escape" followed by a letter will be the equivalent of the
   ASCII "control" "letter", written as Xc (where X is the letter).
   This will greatly simplify the conventions for users, as they will
   simply key "[2]A" where they are used to using Ac and so forth.  For
   completeness, however, there needs to be a way to key the additional
   control characters which require both "control" and "shift" in
   addition to a letter (such as ESC, which is SHIFT Mc).  Further it is
   desirable that a more mnemonic system be provided for the non-
   Teletype user, who knows he wants a LF but does not know that it is a
   Jc.  To satisfy both of these needs I recommend the "ASCII control"
   special function, which is used to enter any of the ASCII control
   character as "[2]@" followed by the standard two or three character
   abbreviation.  Thus "escape" would be [2]@ESC, "line feed" would be
   [2]@LF, and so forth.  The use of the variable length abbreviation
   does not introduce any ambiguity, although from an implementation
   standpoint it may be advantageous to use the two character
   abbreviation proposed in RFC #110.

   Finally we must be able to enter the eight ASCII graphics which do
   not appear on either 2741 terminal, as well as the "cent sign" and
   "backspace" themselves (without their special functions).  For these
   I recommend the following:





Hathaway