RFC 292 (rfc292) - Page 1 of 10
Graphics Protocol: Level 0 only
Alternative Format: Original Text Document
Network Working Group 12 January 1972
Request for Comment: 292 Jim Michener, MAC
NIC 8302 Ira Cotton, MITRE
References: 282, 285 Karl Kelley, U. of Ill.
Updates: None Dave Liddle, Owens Ill.
Obsoletes: None Ed Meyer, MAC
GRAPHICS PROTOCOL - LEVEL 0 ONLY
INTRODUCTION
This document reflects opinions expressed and decisions reached at
the second meeting of the Network Graphics Group, held at the
Stanford Artificial Intelligence Laboratory in late November 1971.
It describes part of a proposed Network Standard Graphics Protocol
for transmitting graphics data within the ARPA network. The
particular aspects of the protocol covered in this document relate to
the form and content of graphics information sent from a source of
graphical information (an application program, say, in the "Serving
Host") to a display package for output to a graphics console (at the
"Using Host"). This will take the form of a sequence of 8-bit bytes,
and will be called the graphics output byte stream. In particular,
only the simplest forms of graphics data will be covered in this, the
first version of this document. The next version, already in
preparation, will be much more complete. In any case this is not
intended to describe a finished protocol; rather it should serve as a
basis for graphics experimentation on the network.
This document does not include form or content of graphics input
(data sent from the Using Host to the Serving Host) nor does it cover
how the connection is established between the hosts. A proposal for
the former will be generated eventually by this committee; the latter
is the job of the Connection Committee (of the Network Graphics
Group).
This RFC describes the commands which are available in the protocol
in terms of the effect they would have at the receiving (Using Host)
end. Clearly, some subroutine package is desirable at the Serving
Host for use by applications package in transmitting graphics data,
but on this topic this RFC does not intend to comment.
It may be observed by the reader that no facility is specified in
this protocol allowing the Using Host to report logical errors in the
graphics output byte stream to the Serving Host. Such a facility
would have to be intergrated with the graphics _input_ byte stream,
since it involves most of the problems related to synchrony of
independent hosts.
Michener
