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Raster Graphics for Interactive Programming Environments

IP.com Disclosure Number: IPCOM000128906D
Original Publication Date: 1979-Jun-01
Included in the Prior Art Database: 2005-Sep-20
Document File: 25 page(s) / 83K

Publishing Venue

Software Patent Institute

Related People

Sproull, R.F.: AUTHOR [+3]

Abstract

Computer graphics has yet to have much impact on interactive computing as a whole. Several arguments suggest that the frame-buffer raster-scan display may substantially enrich the average interactive programming environment. First, a frame-buffer display offers virtually limitless opportunities in the range of graphical imagery that can be presented. Second, controlling such a display, even with low-level operations, is straightforward and intuitive for programmers and designers of interactive systems. Initially, the displays will be increasingly economical as prices of memory and computing drop.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 4% of the total text.

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THIS DOCUMENT IS AN APPROXIMATE REPRESENTATION OF THE ORIGINAL.

©; Xerox Palo Alto Research Center, June, 1979

Raster Graphics for Interactive Programming Environments

Robert F. Sproull

CSL 79 6 June 1979; reprinted August 1982
Copyright Association for Computing Machinery 1979. Printed with permission.

Abstract: Raster-scan display terminals can significantly improve the quality of interaction with conventional computer systems. The design of a graphics package to provide a "window" into the extensive programming environment of Interlisp is presented. Two aspects of the package are described: first, the functional view of display output and interactive input facilities as seen by the programmer, and second, the methods used to link the display terminal to the main computer via a packet-switched computer network. Recommendations are presented for designing operating systems and programming languages so as to simplify attaching display terminals. An appendix contains detailed documentation of the graphics package.

A shortened version of this paper appeared in, Computer Graphics, Summer 1979. CR categories: 8.2, 6.35, 4.35.

Key words and phrases: computer graphics, raster scan display, frame buffer, computer networks, network graphics.

XEROX Xerox Corporation

Palo Alto Research Centers 3333 Coyote Hill Road
Palo Alto, California 94304

1. Introduction

Computer graphics has yet to have much impact on interactive computing as a whole. Several arguments suggest that the frame-buffer raster-scan display may substantially enrich the average interactive programming environment. First, a frame-buffer display offers virtually limitless opportunities in the range of graphical imagery that can be presented. Second, controlling such a display, even with low-level operations, is straightforward and intuitive for programmers and designers of interactive systems. Initially, the displays will be increasingly economical as prices of memory and computing drop.

This paper describes a system that extends the interactive facilities of Interlisp [ Teitelman78 ] to make effective USC of a display for communicating with the lisp programmer. The user's view of DLISP, the display-oriented programmer's assistant, is summarized in the first section of this paper, and described in detail in [ Teitelman77a ] or [ Teitelman77b ] .

The remaining two sections of the paper describe the design of ADIS, the graphics package that supports DLisp. The first shows how good interactive response can be provided in a modest rastersean system. 'The pitfall that must be avoided is exhaustive scan-conversion of the picture whenever a portion is altered. The key idea used to address this problem is to provide mechanisms for copying and manipulating entire regions of a frame buffer at high speed.

Xerox Corporation Page 1 Jun 01, 1979

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Raster Graphics for Interactive Programming Environments

The last section shows how a graphics terminal can be connected to an applica...