Browse Prior Art Database

SUPDUP graphics extension (RFC0746) Disclosure Number: IPCOM000003793D
Original Publication Date: 1978-Mar-01
Included in the Prior Art Database: 2019-Feb-14
Document File: 15 page(s) / 19K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

R. Stallman: AUTHOR

Related Documents

10.17487/RFC0746: DOI

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 12% 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


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).


NWG/RFC# 746 RMS 17-MAR-78 43976 The SUPDUP Graphics Extension

SUPDUP Initial Negotiation:

One new optional variable, the SMARTS variable, is defined. It should follow the other variables sent by the SUPDUP user process to the SUPDUP server process. Bits and fields in the left half-word of this variable are given names starting with "%TQ". Bits and fields in the right half are given names starting with "%TR". Not all of the SMARTS variable has to do with the graphics protoc...