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.

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