RFC 86 (rfc86) - Page 2 of 6
Proposal for a Network Standard Format for a Data Stream to Control Graphics Display
Alternative Format: Original Text Document
The NGDS is accepted into the local Host and interpreted by the NGSI. The
NGSI is a process which modifies the NGDL according to inputs in the NGDS.
The NGDL is the display list for the NGLI; the NGLI executes the NGDL and
controls the beam which writes on the NGS.
The NGS is square, has horizontal and vertical sides, and positions on it
are specified by an ordered pair of unsigned 16 bit fractions. The first
fraction specifies the horizontal distance from the left hand edge, and
the second specifies the vertical distance from the bottom edge. The
resolution of the screen is unspecified.
The lack of specification of the resolution of the NGS is intentional;
programs designers should not interpret this to mean that they may impose
a particular requirement on the using system. Thus the quality of the
displayed picture should degrade gradually with decreasing resolution.
The NGLI has primitives for moving the beam to a particular point, intensify-
ing a point, drawing a vector, or drawing a character. Characters are
assumed to be not more than .015 screen width wide, and not more than .025
screen height high. When the beam is moved to a screen position before
drawing characters, that position should be at the lower left hand corner
of the first character drawn. The beam position after drawing a character
is immediately to the right of the character, properly positioned for another
character. However, after drawing one or more characters, the exact horizontal