Graphics implementation and conceptualization at Augmentation Research Center (RFC0191)
Original Publication Date: 1971-Jul-01
Included in the Prior Art Database: 2019-Feb-10
Internet Society Requests For Comment (RFCs)
RFC 191 Charles Irby NIC 7136 Augmentation Research Center Category D.6, I.1 Stanford Research Institute 13-JUL-71
GRAPHICS IMPLEMENTATION AND CONCEPTUALIZATION AT ARC
This document is a brief description of the way in which graphics terminals are conceptualized and used at the Augmentation Research Center. All things described are implemented and have been operational for several months. Although our attention has initially been centered about the display of textual material, we are now about to turn our attention toward pictorial displays (hopefully much enhanced over our previous 940 line drawing capabilities).
This document will discuss only those facits of display use which have been implemented and are currently operational, namely only those dealing with textual display.
included is a discussion of the use of multiple file viewing display areas in NLS to provide cross file editing capabilities. A description of our display and terminal input equipment will be issued as a separate document.
NOTE: RFC 190 includes a functional description of the implementation of the interface to our displays and is a description of the way this interface was extended to include "Processor-displays" (an IMLAC PDS-1, in this case) to our system, thus enabling one to use Display NLS over any of our teletype lines (including the network).
A "processor dsplay" is a display with Processing power which can be controlled by character strings.
Description of the "conceptual display" implemented at ARC
The allocatable output unit for our display terminals (which include our local terminals and all remote processor-displays) is
a rectangular "display area". A program treats this display area much like it would a file which it has opened with write access.
When requesting the allocation of a display area, a program specifies its attributes, including where it is to be on the screen. The program is returned an identifier which it subsequently uses to manipulate images within the display area and the display area itself. Each string which the program writes into the display area is also given an identifier, which can subsequently be used to move, delete, replace, or change the characteristics of that string.
The currently implemented characteristics are character size, horizontal spacing between characters, and font of the characters (e.g. blinking, italics, intensity, etc.).
The position of items in the display area are given relative to the 0,0, which is the lower left corner of the display area. The horizontal coordinate increases to the right and the vertical coordinate increases toward the top.
In addition to above described manipulation of strings within display areas a program can suppress the display of individual strings within display areas or suppress whole display areas.
Also, a program can switch the terminal’s state from teletype simulation to display mode and vis versa.
When in display mode, the teletype simulation display area is su...