Report Number: CS-TR-68-114
Institution: Stanford University, Department of Computer Science
Title: Calgen - an interactive picture calculus generation system
Author: George, James E.
Date: December 1968
Abstract: A sub-set of the Picture Calculus was implemented on the IBM 360/75 to experiment with the proposed data structure, to study the capability of PL/1 for implementing the Picture Calculus and to evaluate the usefulness of drawing pictures with this formalized language. The system implemented is referred to as Calgen. Like many other drawing proggrams, Calgen utilizes a graphic display console; however, it differs from previous drawing systems in one major area, namely, Calgen retains structure information. Since the Picture Calculus is highly structured, Calgen retains structure information, and only scope images where convenient; further, these scope images saved may be altered by changing the structure information. The only reason scope images are saved by Calgen is to avoid regeneration of a previously generated picture.
http://i.stanford.edu/pub/cstr/reports/cs/tr/68/114/CS-TR-68-114.pdf