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NWG/RFC# 747                                         MRC 21-MAR-78 44015
Recent Extensions to the SUPDUP Protocol



Network Working Group                                       Mark Crispin
Request for Comments 747                                           SU-AI
NIC 44015                                                  21 March 1978

Updates: RFC 734.  See also RFC 746.

                Recent Extensions to the SUPDUP Protocol

Recently,  some extensions  have been made to the SUPDUP protocol.   RFC
746,  by Richard   Stallman, documented  the SUPDUP  graphics extension.
In addition, a TTYOPT  bit has  been added and  two more  variables have
been added to the initial  negotiation.   This RFC describes the changes
from  RFC 734,  but excludes  the  detailed  information  in   RFC  746.
These  extensions  are  upwards  and   downwards  compatable,   and  are
completely  optional.    For most  SUPDUP   user  and  server  programs,
RFC   734   remains    an   adequate   description  of   the   protocol.
However,   it  is  suggested   that  if  the  console's  line  speed  is
known,  the  user SUPDUP  should be modified to  send the new ISPEED and
OSPEED  variables   (sending  0 for SMARTS if the  graphics extension is
not to  be used)  so  the server can  handle buffering for  the terminal
better.

Since these changes  are compatable  and optional, and since the  SUPDUP
protocol is being actively worked on at the present time, I have elected
to issue  this  update  RFC  rather  than  an  updated  version   of RFC

734. An updated 734 will be issued when the protocol stabilizes again.

Three new variables have been added to the initial negotiation. In order, they are SMARTS, ISPEED, and OSPEED. Consequently, the count should now be -10,,0, or, in octal, 777770000000. The SMARTS variable specifies what "smarts" (in general, what graphics capabilities) the terminal has. Like the TTYOPT variable, a bit being true implies that the terminal has this option. RFC 746 describes this variable and the SUPDUP graphics option in complete detail. If the graphics extension is not to be used, SMARTS should be set to 0. The ISPEED and OSPEED variables are respectively the input and output baud rates of the terminal, if known. For example, a 150./1200. baud terminal would have an ISPEED of 150. and an OSPEED of 1200. A speed of zero means the line speed is indeterminate. The %TPPRN TTYOPT bit (value 0,,200) has been added. This bit specifies that the system should swap parenthesis with square brackets on input. This is often desirable for LISP users who are using a terminal which has parenthesis as a shift character but not square brackets. This bit is normally off and servers are not required to implement it. -1-