Browse Prior Art Database

SUPDUP graphics extension (RFC0746)

IP.com Disclosure Number: IPCOM000003793D
Original Publication Date: 1978-Mar-17
Included in the Prior Art Database: 2000-Sep-13
Document File: 12 page(s) / 30K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

R. Stallman: AUTHOR

Abstract

... extends SUPDUP to permit the display of drawings on the screen of the terminal, as well as text. We refer constantly to the documentation of the SUPDUP protocol, described by Crispin in RFC 734 "SUPDUP Protocol".

This text was extracted from a ASCII Text document.
This is the abbreviated version, containing approximately 10% of the total text.

NWG/RFC# 746 RMS 17-MAR-78 43976

The SUPDUP Graphics Extension

Network Working Group Richard Stallman

Request for Comments 746 MIT-AI

NIC 43976 17 March 1978

The SUPDUP Graphics Extension

... extends SUPDUP to permit the display of drawings on the screen of

the terminal, as well as text. We refer constantly to the

documentation of the SUPDUP protocol, described by Crispin in RFC 734

"SUPDUP Protocol".

Since this extension has never been implemented, it presumably has

some problems. It is being published to ask for suggestions, and to

encourage someone to try to bring it up.

The major accomplishments are these:

* It is easy to do simple things.

* Any program on the server host can at any time begin outputting

pictures. No special preparations are needed.

* No additional network connections are needed. Graphics commands

go through the normal text output connection.

* It has nothing really to do with the network. It is suitable

for use with locally connected intelligent display terminals in

a terminal-independent manner, by programs which need not know

whether they are being used locally or remotely. It can be used

as the universal means of expression of graphics output, for

whatever destination. Programs can be written to use it for

non-network terminals, with little loss of convenience, and

automatically be usable over the ARPA network.

* Loss of output (due, perhaps, to a "silence" command typed by

the user) does not leave the user host confused.

* The terminal does not need to be able to remember the internal

"semantic" structure of the picture being displayed, but just

the lines and points, or even just bits in a bit matrix.

* The server host need not be able to invoke arbitrary

terminal-dependent software to convert a standard language into

one that a terminal can use. Instead, a standard language is

defined which all programmable terminals can interpret easily.

Major differences between terminals are catered to by

conventions for including enough redundant information in the

output stream that all types of terminals will have the

necessary information available when it is needed, even if they

-1-

NWG/RFC# 746 RMS 17-MAR-78 43976

The SUPDUP Graphics Extension

are not able to remember it in usable form from one command to

another.

Those interested in network graphics should read about the Multics

Graphics System, whose fundamental purpose is the same, but whose

particular assumptions are very different (although it did inspire a few

of the features of this proposal).

-2-

NWG/RFC# 746 ...