• Source: 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.




History


See History of the graphical user interface for a more detailed discussion of GUI development.




Software



Sketchpad was the earliest program ever to use a complete graphical user interface.
The clever way the program organizes 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 can be instantiated into many duplicates. When a master drawing is changed, then all instances change also.
Geometric constraints was another major invention in Sketchpad, letting a 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. Hanratty is sometimes called the "father of CAD/CAM" and wrote PRONTO, a numerical control language at General Electric in 1957, and wrote CAD software while working for General Motors beginning in 1961. Sutherland wrote in his thesis that Bolt, Beranek and Newman had a "similar program" and T-Square was developed by Peter Samson and one or more fellow MIT students in 1962, both for the PDP-1.
The Computer History Museum holds program listings for Sketchpad.




Hardware


Sketchpad ran on the MIT Lincoln Laboratory TX-2 (1958) computer at the Massachusetts Institute of Technology (MIT), which had 64k of 36-bit words. The user drew on the computer monitor screen with the recently invented light pen, which relayed information on its position by computing at what time the light from the scanning cathode-ray tube screen is detected.
To configure the initial position of the light pen, the word INK was displayed on the screen, which, upon tapping, initialised the program with a white cross to continue keeping track of the pen's movement relative to its prior position. Of the 36 bits available to store each display spot in the display file, 20 gave the coordinates of that spot for the display system and the remaining 16 gave the address of the n-component element responsible for adding that spot to display.
The TX-2 was an experimental machine and the hardware changed often (on Wednesdays, according to Sutherland). By 1975, the light pen and the cathode-ray tube with which it had been used had been removed.




Publications


The Sketchpad program was part and parcel of Sutherland's Ph.D. thesis at MIT and peripherally related to the Computer-Aided Design project at that time.
Sketchpad: A Man-Machine Graphical Communication System.




See also


Comparison of CAD software




References






Bibliography


Coons, Steven (1964). Fitch, John (ed.). "Computer Sketchpad" (episode). Science Reporter., explains the principles of Sketchpad.
Kay, Alan (1987). "Pt 1". Doing with Images Makes Symbols (video presentation). University Video Communications – via Archive.
Müller-Prove, Matthias. "Graphical User Interface of Sketchpad". Germany: MProve.
Sutherland, Ivan Edward (1980). Sketchpad: A Man-Machine Graphical Communication System (PhD thesis). New York: Garland Publishers. ISBN 0-8240-4411-8.
Sutherland, Ivan Edward. Sketchpad: A man-machine graphical communication system (PDF) (PhD thesis). UK: CAM. Technical Report No. 574.
Sutherland, Ivan Edward. "Sketchpad: A Man-Machine Graphical Communication System". AFIPS conference proceedings (PhD thesis). PL: ACI. Archived from the original on 2005-04-22.
Yares, Evan (February 2013). "50 Years of CAD". Design World: 66–71.




External links



——— (30 January 1963), Sketchpad: A Man-Machine Graphical Communication System (PDF), Lincoln Laboratory, Massachusetts Institute of Technology via Defense Technical Information Center, Technical Report No. 296, archived from the original on April 8, 2013, retrieved 2007-11-03{{citation}}: CS1 maint: unfit URL (link).
Archived at Ghostarchive and the Wayback Machine: "Sketchpad", Youtube.
Demo 1, 2
• Source: SketchPad

SketchPad is a coworking space in Chicago for Jewish nonprofits.




History


Founded by Irene Lehrer Sandalow, SketchPad is part of a limited collection of global Jewish-themed co-working spaces, including New York, Encinitas (California), London, and Melbourne. The concept took shape in 2015, a year after Lehrer Sandalow relocated to Chicago with her husband. Engaged in remote work on a project for the Union for Reform Judaism during that period, she conceived the idea of SketchPad. Following collaborative discussions with local Jewish organizations and successful grant acquisitions, she established SketchPad in 2017.
Susan Morrow is a board chair for SketchPad.




References






External links


Official website

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