Sketchpad

Infobox Software
name = Sketchpad



caption = Ivan Sutherland demonstrating Sketchpad (UVC via IA: [http://www.archive.org/details/AlanKeyD1987 video] and [http://www.archive.org/movies/thumbnails.php?identifier=AlanKeyD1987 thumbnails] )
author = Ivan E. Sutherland
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released = 1963
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platform = Lincoln TX-2
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genre = animation, drawing, drafting, CAD
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Sketchpad (aka Robot Draftsman) was a revolutionary computer program written by Ivan Sutherland in 1963 in the course of his PhD thesis, for which he received the Turing Award in 1988. It helped change the way people interact with computers. Sketchpad is considered to be the ancestor of modern computer-aided drafting (CAD) programs as well as a major breakthrough in the development of computer graphics in general. For example the Graphic User Interface was derived from the Sketchpad as well as modern object oriented programming. Ivan Sutherland demonstrated with it that computer graphics could be used for both artistic and technical purposes in addition to showing 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.

Sketchpad was the first program ever to utilize a complete graphical user interface, using an x-y point plotter display and the recently invented light pen. The clever way the program organized its geometric data pioneered the use of "objects" and "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. Another major invention in Sketchpad was that it let 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. Sketchpad ran on the Lincoln TX-2 (1958) computer at MIT, which had 64k of 36 bit-words. 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.

Bolt, Beranek and Newman had a "similar program"cite web | last=Sutherland | first=Ivan Edward | title=Sketchpad: A man-machine graphical communication system (courtesy Computer Laboratory, University of Cambridge UCAM-CL-TR-574 September 2003) | publisher=Massachusetts Institute of Technology | month= January | year= 1963 | url=http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-574.html | accessdate=2006-12-26] and T-Square was developed by Peter Samson and one or more fellow MIT students in 1962, both for the PDP-1. [cite web| author=Computer History Museum | title=The Mouse that Roared: PDP-1 Celebration Event (Running Time: 01:53:46)| date= 15 May, 2006| url=http://video.google.com/videoplay?docid=4995476926708958999&q=computer+history+dec | accessdate=2006-12-28]

In 1963 most computers ran jobs in batch job mode only, using punch cards or magnetic tape reels submitted by professional programmers or engineering students. A considerable amount of work was required to make the TX-2 operate in interactive mode with a large CRT screen. When Sutherland had finished with it, it had to be reconverted to run in batch mode again. This involved some major hardware reconstruction as well as software work.

The Sketchpad program was part and parcel of Sutherland's Ph.D. thesis at MIT. It was reprinted in 1980 under the title "Sketchpad: A Man-Machine Graphical Communication System". It is now out of print but several university libraries have copies and it is also present on the rare book market. For a PhD thesis it is remarkably clear and readable. A new PDFlink| [http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-574.pdf electronic edition] |3.90 MiB was published in 2003.

See also

*Comparison of CAD Software

References

* Kay, Alan "Doing with Images Makes Symbols Pt 1" [http://www.archive.org/details/AlanKeyD1987 Video presentation by Alan Kay] that demonstrates Sketchpad (Sketchpad demo starts at 2:54).
* Müller-Prove, Matthias " [http://www.mprove.de/diplom/text/3.1.2_sketchpad.html Graphical User Interface of Sketchpad] "
* Sutherland, Ivan Edward. "Sketchpad: A Man-Machine Graphical Communication System". New York: Garland Publishers, 1980. ISBN 0-8240-4411-8.
* Sutherland, Ivan PDFlink| [http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-574.pdf Sketchpad: A man-machine graphical communication system] |3.90 MiB , Ivan Sutherland's PhD Thesis.
* Sutherland, Ivan Edward. [http://www.aci.com.pl/mwichary/guidebook/articles/historical/sketchpad Sketchpad: A Man-Machine Graphical Communication System] , a paper from AFIPS conference proceedings.
* Coons, Steven "Computer Sketchpad" [http://www.wgbh.org/article?item_id=3360989 1964 Episode of Science Reporter] hosted by John Fitch, explains the principles of "Sketchpad".

Notes

External links

*cite web|author=Sutherland, Ivan Edward, preface by Alan Blackwell and Kerry Roddenphone|title=Sketchpad: A Man-Machine Graphical Communication System|month=September | year=2003|url=http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-574.pdf|publisher=Technical Report No. 574, University of Cambridge, UCAM-CL-TR-574|format=PDF|ISSN 1476-2986|accessdate=2007-11-03
*cite web|author=Sutherland, I. E.|title=Sketchpad: A Man-Machine Graphical Communication System|date=30 January 1963|url=http://handle.dtic.mil/100.2/AD404549|publisher=Technical Report No. 296, Lincoln Laboratory, Massachusetts Institute of Technology via Defense Technical Information Center (stinet.dtic.mil)|format=PDF|accessdate=2007-11-03