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The first graphic system was in mid 1950 the US Air Force's SAGE (Semi Automatic Ground Environment) air defense system. The system was developed at Massachusetts Institute of Technology's Lincoln Laboratory. The system involved the use of CTR displays to show computer-processed radar data and other information. In 1960, Ivan Sutherland used TX-2 computer produced at MIT's Lincoln Laboratory to produce a project called SKETCHPAD, which is considered the first step to CAD industry. Parallel projects were developed at ITEK and General Motors. The ITEK project was called The Electronic Drafting Machine and used PDP-1 computer from Digital Equipment Corp., a vector -refresh display and a large disk memory device used to refresh the graphic display. Inputs commands were done with an electronic light pen. In 1960 McDonnell? Douglas Automation Company (McAuto?) founded. It will play a major role on CAD developments. The first Computer-Aided Design programs used simple algorithms to display patterns of lines at first in two dimensions, and then in 3-D. Early work in this direction had been produced by Prof. Charles Eastman at Carnegie-Mellon University, the Building Description System is a library of several hundred thousands architectural elements, which can be assembled and drawn on screen into a complete design concept. In 1962, SLS Environectics in Chicago began development of the Man-Mac machine, intended to draft plans for interior office space. In mid 1960 large computers characterized the period, vector display terminals and software development done in assembly language. The only significant attempt to create a commercially CAD system was Control Data Corporation's Digigraphics division, a successor to the previously mentioned ITEK. The system costs half million dollars and were sold in few units. In March 1965 Donald Welbourn heard a lecture to the Engineering Society by Strachey of the Mathematical Laboratory (now the Department of Computer Science) on the early work at MIT on Computer Aided Design (CAD). He was so fascinated by this that the following morning he caught the Head of the Cambridge University Engineering Department, Prof. J.F.Baker (later the Lord Baker of Trumpington) in the tea-room, told him about it, and said that we must get started in this field. Baker was enthusiastic, and by the end of the year, the Science Research Council had awarded Baker and Welbourn a grant of £65,000 with which to start work on CAD. Initially work was done on the PDP11 graphics computer and a joint team was formed under the leadership of C.A.Lang. The first research student was A.R.Forrest, who tackled the problem of how to define the blended intersection of two cylinders. The conceptual breakthrough of defining objects in terms of 3D reference lines, analogous to the draughtsman's centre line, together with cross-sections normal to them, was produced by S.Matthews, seconded by the Ford Motor Co. In 1968 Donald Welbourn, now the Director in Industrial Co-Operation at Cambridge University, had the vision to see the possibility of using computers to assist pattern makers to solve the problems of modelling difficult 3D shapes. Today we take for granted 3D modelling, in 1968 only crude 2D drawing systems were available using terminals linked to large main frame computers. Initial work was sponsored by Ford but finding money to support the development was a constant problem for Donald Welbourn. Only six years later he managed to obtain sponsorship from Control Data in Germany, and Delta Engineering Group. Control Data offered DUCT initially as a bureau services, especially to two of its largest German customers Volkswagen and Daimler Benz. David Evans and Ivan Sutherland founded in 1968 Evans and Sutherland. In 1969 were founding Computervision and Applicon companies. Computervision was created to produce systems for production drafting and in the same year it sold the first commercial CAD system to Xerox. |
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