Sketchpad

Sketchpad (a.k.a. Robot Draftsman) is a computer program written by Ivan Sutherland in 1963 in the course of his PhD thesis, for which he received the Turing Award in 1988, and the Kyoto Prize in 2012. It pioneered human–computer interaction (HCI), and is considered the ancestor of modern computer-aided design (CAD) programs as well as a major breakthrough in the development of computer graphics in general. For example, the graphical user interface (GUI) was derived from Sketchpad as well as modern object-oriented programming. Using the program, Ivan Sutherland showed that computer graphics could be used for both artistic and technical purposes in addition to demonstrating a novel method of human–computer interaction. Sutherland was inspired by the Memex from "As We May Think" by Vannevar Bush. Sketchpad inspired Douglas Engelbart to design and develop oN-Line System at the Augmentation Research Center (ARC) at the Stanford Research Institute (SRI) during the 1960s. See History of the graphical user interface for a more detailed discussion of GUI development. Sketchpad was the earliest program ever to utilize a complete graphical user interface. The clever way the program organized its geometric data pioneered the use of "master" ("objects") and "occurrences" ("instances") in computing and pointed forward to object oriented programming. The main idea was to have master drawings which one could instantiate into many duplicates. If the user changed the master drawing, all the instances would change as well. Geometric constraints was another major invention in Sketchpad, letting the user easily constrain geometric properties in the drawing—for instance, the length of a line or the angle between two lines could be fixed. As a trade magazine said, clearly Sutherland "broke new ground in 3D computer modeling and visual simulation, the basis for computer graphics and CAD/CAM". Very few programs can be called precedents for his achievements. Patrick J.