Sketchpad

{{Short description|Computer program written by Ivan Sutherland in 1963}}

{{For-multi|the physical item|Sketchbook|the coworking space in Chicago|SketchPad}}

{{Infobox software

| name = Sketchpad

| screenshot = Sketchpad-Apple.jpg

| caption = Ivan Sutherland demonstrating Sketchpad (UVC via IA: [https://archive.org/details/AlanKeyD1987 video] and [https://archive.org/movies/thumbnails.php?identifier=AlanKeyD1987 thumbnails])

| author = Ivan Sutherland

| developer = MIT Lincoln Laboratory

| released = {{Start date and age|1963}}

| programming language = TX-2 assembly language

| operating system = none

| platform = Lincoln TX-2

| language = English

| genre = animation, drawing, drafting, CAD

| license =

| website =

}}

Sketchpad (a.k.a. Robot Draftsman{{Cite book |last1=Armstrong |first1=Helen |date=7 June 2016 |title=Digital design theory: readings from the field |publisher=Princeton Architectural Press |isbn=978-1-61689-308-8 |location=New York |page=9}}) 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),{{cite book |last1=Sears |first1=Andrew |last2=Jacko |first2=Julie A. |date=19 September 2007 |title=The Human–Computer Interaction Handbook: Fundamentals, Evolving Technologies and Emerging Applications, Second Edition |url=https://books.google.com/books?id=A8TPF_O385AC&pg=PA5 |access-date=1 March 2013 |publisher=CRC Press |page=5 |isbn=978-1-4106-1586-2}} and is considered the ancestor of modern computer-aided design (CAD) programs and as a major breakthrough in the development of computer graphics in general. For example, Sketchpad inspired the graphical user interface (GUI) and object-oriented programming. Using the program, Sutherland showed that computer graphics could be used for both artistic and technical purposes and for 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

File:Sketchpad N-Component Element.png

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".{{cite news |url=http://americanmachinist.com/cadcam-software/cadcam-hall-fame |title=The CAD/CAM Hall of Fame |work=American Machinist |publisher=Penton Media |date=November 1, 1998 |access-date=March 18, 2013}} Very few programs can be called precedents for his achievements. Patrick J. Hanratty is sometimes called the "father of CAD/CAM"{{cite news |title=Patrick Hanratty spotlight |url=http://www.ics.uci.edu/community/news/spotlight/spotlight_hanratty.php |date=October 18, 2012 |publisher=The Regents of the University of California |access-date=March 17, 2013}} 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"{{cite web |last1=Sutherland |first1=Ivan Edward |author1-link=Ivan Sutherland |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 |date=January 1963 |url=http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-574.html |access-date=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 |title=The Mouse that Roared: PDP-1 Celebration Event (running time: 01:53:46) |date=15 May 2006 |url=http://archive.computerhistory.org/resources/moving-image/DEC/PDP-1_Online/dec.the_mouse_that_roared_pdp_1_celebration_event.lecture.2006.102654189.wmv |website=Computer History Museum |access-date=2013-03-14}}

The Computer History Museum holds program listings for Sketchpad.{{cite web |last1=Sutherland |first1=Ivan E. |author1-link=Ivan Sutherland |date=1963 |title=Sketchpad listings |url=https://www.computerhistory.org/collections/catalog/102726903 |access-date=2021-10-30}}

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{{cite journal |last1=Sutherland |first1=Ivan |author1-link=Ivan Sutherland |date=2012 |title=The TX-2 Computer and Sketchpad |journal=Lincoln Laboratory Journal |volume=19 |issue=1 |pages=82–84 |url=https://www.ll.mit.edu/sites/default/files/page/doc/2018-05/LookingBack_19_1.pdf |access-date=6 November 2022}}). By 1975, the light pen and the cathode-ray tube with which it had been used had been removed.{{cite web |last1=Youngman |first1=James |date= |title=Sequence Changes |url=https://tx-2.github.io/commentary/sequence-changes#crt |website=TX-2 Project |access-date=26 November 2024}}

Publications

The Sketchpad program was part and parcel of Sutherland's Ph.D. thesis at MIT and peripherally related to the [http://images.designworldonline.com.s3.amazonaws.com/CADhistory/8436-TM-4.pdf Computer-Aided Design project] at that time.

[http://images.designworldonline.com.s3.amazonaws.com/CADhistory/Sketchpad_A_Man-Machine_Graphical_Communication_System_Jan63.pdf Sketchpad: A Man-Machine Graphical Communication System].

See also

References

{{Reflist}}

Bibliography

  • {{Cite web |last1=Coons |first1=Steven |author1-link=Steven Anson Coons |editor1-last=Fitch |editor1-first=John |year=1964 |title=Computer Sketchpad |url=http://www.wgbh.org/article?item_id=3360989 |type=episode |series=Science Reporter}} Explains basic Sketchpad principles.
  • {{Cite AV media |last1=Kay |first1=Alan |author1-link=Alan Kay |date=16 July 2007 |title=Sketchpad, by Dr. Ivan Sutherland with comments by Alan Kay |url=https://m.youtube.com/watch?v=495nCzxM9PI |type=video |language=en |place=Palo Alto, California |publisher=Xerox PARC |via=David Carroll; YouTube |url-status=live |archive-url=https://web.archive.org/web/20091218123245/http://www.youtube.com/watch?v=495nCzxM9PI |archive-format=Flash |archive-date=18 December 2009 |access-date=25 April 2025}} Archive 2: [https://ghostarchive.org/varchive/youtube/20211211/495nCzxM9PI Ghostarchive]{{Cbignore}}
  • {{Cite AV media |last1=Kay |first1=Alan |author1-link=Alan Kay |date=1987 |title=Doing with Images Makes Symbols |chapter=Pt 1 |url=https://archive.org/details/AlanKeyD1987 |type=video presentation |at=4min5 |publisher=University Video Communications |via=Archive}}
  • {{Cite AV media |last1=Kay |first1=Alan |author1-link=Alan Kay |date=21 February 2024 |title=Alan Kay's talk at UCLA 2024 February 21st |url=https://m.youtube.com/watch?v=dZQ7x0-MZcI |type=video |language=en |publication-place=Los Angeles, California |place=London, England |publisher=Yoshiki Ohshima (大島芳樹) |via=YouTube |time=44:15–51:46 |time-caption=Kay narates Sketchpad operation at |access-date=24 April 2025}}
  • {{Cite web |last1=Müller-Prove |first1=Matthias |date= |url=http://www.mprove.de/diplom/text/3.1.2_sketchpad.html |title=Graphical User Interface of Sketchpad |publisher=MProve |place=Germany}}
  • {{Cite thesis |last1=Sutherland |first1=Ivan Edward |author1-link=Ivan Sutherland |year=1980 |title=Sketchpad: A Man-Machine Graphical Communication System |degree=PhD |place=New York |publisher=Garland Publishers |isbn=0-8240-4411-8}}
  • {{Cite thesis |last1=Sutherland |first1=Ivan Edward |author1-link=Ivan Sutherland |url=http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-574.pdf |title=Sketchpad: A man-machine graphical communication system |degree=PhD |publisher=CAM |place=UK |id=Technical Report No. 574}}
  • {{Cite thesis |last1=Sutherland |first1=Ivan Edward |author1-link=Ivan Sutherland |url=http://www.aci.com.pl/mwichary/guidebook/articles/historical/sketchpad |contribution=Sketchpad: A Man-Machine Graphical Communication System |degree=PhD |title=AFIPS conference proceedings |publisher=ACI |place=PL |url-status=dead |archive-url=https://web.archive.org/web/20050422075646/http://www.aci.com.pl/mwichary/guidebook/articles/historical/sketchpad |archive-date=2005-04-22}}
  • {{Cite journal |last1=Yares |first1=Evan |date=February 2013 |title=50 Years of CAD |url=http://www.designworldonline.com/50-years-of-cad/ |journal=Design World |pages=66–71}}