Template:Short description Template:For-multi {{#invoke:Infobox|infobox}}Template:Template other{{#invoke:Check for unknown parameters | check | showblankpositional=1 | unknown = Template:Main other | preview = Page using Template:Infobox software with unknown parameter "_VALUE_"|ignoreblank=y | AsOf | author | background | bodystyle | caption | collapsetext | collapsible | developer | discontinued | engine | engines | genre | included with | language | language count | language footnote | latest preview date | latest preview version | latest release date | latest release version | latest_preview_date | latest_preview_version | latest_release_date | latest_release_version | licence | license | logo | logo alt | logo caption | logo upright | logo size | logo title | logo_alt | logo_caption | logo_upright | logo_size | logo_title | middleware | module | name | operating system | operating_system | other_names | platform | programming language | programming_language | released | replaced_by | replaces | repo | screenshot | screenshot alt | screenshot upright | screenshot size | screenshot title | screenshot_alt | screenshot_upright | screenshot_size | screenshot_title | service_name | size | standard | title | ver layout | website | qid }}Template:Main other Sketchpad (a.k.a. Robot Draftsman<ref>Template:Cite book</ref>) 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),<ref name="SearsJacko2007">Template:Cite book</ref> 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.
HistoryEdit
See History of the graphical user interface for a more detailed discussion of GUI development.
SoftwareEdit
Sketchpad was the earliest program ever to use a complete graphical user interface.<ref name="SearsJacko2007"/>
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".<ref name=Penton>Template:Cite news</ref> Very few programs can be called precedents for his achievements. Patrick J. Hanratty is sometimes called the "father of CAD/CAM"<ref>Template:Cite news</ref> 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"<ref name=IES-thesis>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> and T-Square was developed by Peter Samson and one or more fellow MIT students in 1962, both for the PDP-1.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
The Computer History Museum holds program listings for Sketchpad.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
HardwareEdit
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.<ref name=IES-thesis></ref> 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<ref name="LookingBack">Template:Cite journal</ref>). By 1975, the light pen and the cathode-ray tube with which it had been used had been removed.<ref name="SequenceChanges">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
PublicationsEdit
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 alsoEdit
ReferencesEdit
BibliographyEdit
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