Douglas Taylor "Doug"Ross (21 December 1929 – 31 January 2007) was an Americancomputer scientist pioneer, and chairman ofSofTech, Inc.^[1] He is most famous for originating the term CAD forcomputer-aided design, and is considered to be the father of Automatically Programmed Tools (APT), aprogramming language to drivenumerical control in manufacturing. His later work focused on apseudophilosophy he developed and named Plex.

Ross was born in China, where his parents both worked as medical missionaries, and he then grew up in the United States inCanandaigua, New York.^[2] He received aBachelor of Science (B.Sc.)cum laude inmathematics fromOberlin College in 1951, and aMaster of Science (M.Sc.) inelectrical engineering from theMassachusetts Institute of Technology (MIT) in 1954. Afterward, he began but didn't finish his Ph.D., at MIT due to his pressing work as head of MIT's Computer Applications Group.^[3]

In the 1950s, he participated in the MITWhirlwind I computer project. In 1969, Ross foundedSofTech, Inc., which began as an early supplier of customcompilers for theUnited States Department of Defense (DoD) for the languagesAda andPascal. Ross lectured atMIT Electrical Engineering and Computer Science Department and was chairman emeritus. He retired at Softech, having served as the company's president from 1969 to 1975, when he became chairman of the board of directors.

Among his many honors are theJoseph Marie Jacquard Memorial Award from the Numerical Control Society, in 1975, and the Distinguished Contributions Award from theSociety of Manufacturing Engineers in 1980, and Honorary Engineer of the Year Award from the San Fernando Valley Engineer's Council, 1981.^[3] The MIT Department of Electrical Engineering and Computer Science named after him the Douglas T. Ross Career Development Associate Professor of Software Development. The D.T.Ross Medal Award of the Berliner Kreis Scientific Forum for Product Development of the WiGeP Academic Society of Product Development Berliner Kreis & WGMK was named in his honor.

Ross contributed to the MITWhirlwind I computer project, which was the first to displayreal-time text and graphics. Many consider him to be the father ofAutomatically Programmed Tools (APT), the language that drives numerical control in manufacturing. Also he originated the term CAD forcomputer-aided design.

Ross came to MIT in the fall of 1951^[4] as a teaching assistant in the mathematics department. His wife, Pat, was a "computer banging away on aMarchant calculator" atLincoln Laboratory before it officially took over theWhirlwind I computer. Her group used theServomechanisms Labs analog correlation computer, built byNorbert Wiener. It hadball-and-disk integrators and arms used to hand trace strip chart curves of radar noise data. When the machine was in use, variables in equations were represented by rotations in its shafts. These were connected with mechanical pens which plot an accurate curve worked out by the shafts continuous movement. Interpreted correctly, this curve gave a graphic solution to the problem. This initiated Ross's entry to the Servo Lab with a summer job in June 1952 in the field of airbornefire-control system evaluation andpower density spectra analyses.

The first programming language Ross designed was one in which thecomputer was a group of people, six or eight part-time students. It was suggested that Ross could use Whirlwind in his work. Whirlwind at that time had exactly onekilobyte (k, 1024words) of16-bit memory. He taught himself to program it in the summer of 1952. His masters thesis related to Computational Techniques for Fourier Transformation.

He worked on numerous projects around the Whirlwind secret room of the Cape Cod SystemSAGE air defense system and at the Eglin Air Force BaseERA 1103. Around 1954, Ross wrote the first hand-drawn graphics input program to a computer. He stated it was "One of the few programs that I ever wrote that worked the first time"^[5] The Air Force was interested in continuing beyond MIT'sNumerical Control Projects objective of standardizing the numerical control ofmachine tools.

Starting in 1956, MIT had a contract for a new program in numerical control, this time emphasizing automatic programming for three-dimensional parts to be produced by 3- and 5-axis machine tools. Ross stated his work with radar vector handling led naturally to his defining tool paths as space curves rather than points in APT II, and allowed him to conceptualize their realization in a machine tool's rectilinear framework. The Servo Lab received Air Force sponsorship for numerical control hardware, software, and adaptive control, followed by computer-aided design, computer graphics hardware and software, andsoftware engineering and software technology, from 1951. This continued for almost 20 years.^[6][7] In 1957 the last of Ross's original three research assistants, Sam Matsa,^[8][9] left for IBM to develop AUTOPROMT, a three-dimensional APT derivative, and later (1967) co-founded, with Andy Van Dam, the ACMSICGRAPH.

TheAPT project largely finished in February 1959. It had thecopyright status of works by the federal government of the United States, and thus was released into thepublic domain.^[10][11][12] The legacy of this work can be found innext generation NC programs of the 21st century.

At the conclusion of APT I, Ross and John Francis Reintjes were interviewed for MIT science reporter television by Robert S. Woodbury. There was considerable public interest in the increasing sophistication of numerically controlled machine tools. The interview is illustrative of Ross's long stated belief in the graphics potential of the computer. He showed the audience a photograph of a vector sweep image from a display scope in the form of a Disney cartoon character coupled in a coordinate space with a canonicalgnomon.^[13]

The next few years would see the completing of APT's influential Arithmetic Elements and then the broad collaboration pioneered in the APT project was repeated in building the computer-aided design system namedAutomated Engineering Design (AED). Ross sometimes called it informallyThe Art of Engineering Design orALGOL Extended for Design.

Early industry practitioners of computer aided drafting and manufacturing visited MIT in formal exchanges of the developing technologies. Ross organized many standards making conferences for theAmerican National Standards Institute (ANSI) and Business Equipment Manufacturers Association (BEMA, renamedInformation Technology Industry Council), solidifying his place as a touchstone in any future history of CAD.^[14][15] The next decade brought a refining of his philosophy of system design.^[16][17] He was a founding member ofSociety for Industrial and Applied Mathematics (SIAM).

He was involved with developinginternational standards in programming and informatics, as an early active participant in theInternational Federation for Information Processing (IFIP). He was a member ofIFIP Working Group 2.1 on Algorithmic Languages and Calculi,^[18] whichspecified, maintains, and supports theprogramming languagesALGOL 60 andALGOL 68.^[19] In 1968, Ross taught what he suggested was the world's first software engineering course at MIT. He participated in the foundational NATO Software Engineering Conference in Garmisch, Germany, 7–11 October 1968.^[20][21] Many MIT project users built their systems on AED.^[22] Post Assembly revisions ofJay Wright Forrester's famousDynamo feedback-modeling, System Dynamics simulation language were written in AED-0, Ross's extended version of ALGOL 60 and used into the 1980s.

Ross wrote the onlyALGOL X compiler known to have existed, with the AED-0 system.^[23][24]

SofTech's work on airborne and other instrumentation systems involved building software development tools. By the late 70's microprocessors like the 8086 were starting to be used for these embedded systems. The University of California at San Diego Pascal System (UCSD p-System, seeUCSD Pascal) was developed in 1978 to provide students with a commonoperating system to use on various machines like the PDP-11 minicomputer. Versions of p-System were freely exchanged between interested users. The p-System was brought to Ross's attention by a developer at their San Diego branch [who had anApple I computer]. Ross visited UCSD and was smitten by a college operation building a system he recognized as kindred to his AED efforts. SofTech licensed the p-System and established a Microsystems subsidiary in 1979. SofTech's compiling, dynamic loading, and linking tools helped make the p-System a powerful development environment. UCSD p-System was used onIBM Personal Computer,Apple II, and otherZilog Z80,MOS Technology 6502,Motorola 68000 based machines. Ross later bought the PDP-11 basedTerak 8510/a "graphics workhorse" computer ofKen Bowles which now resides in the Computer History Museum collections.^[25][26]

As the inventor ofstructured analysis and design technique (SADT), Ross was an early developer ofstructured analysis methods.^[27] During the 1970s, along with other contributors fromSofTech, Inc., Ross helped develop SADT into theIDEF0 method for the Air Force'sIntegrated Computer-Aided Manufacturing (ICAM) program'sIDEF suite of analysis and design methods.^[28]

He was a member of theInstitute of Electrical and Electronics Engineers (IEEE) IDEF0 Working Group which produced the IEEEIcam DEFinition for Function Modeling (IDEF0) standard^[29] in 1998. The IEEE IDEF0 standard superseded FIPS PUB 183,^[30] which was retired in 2002.

Ross' Structured Analysis grew out of his "philosophy of problem-solving", which he named Plex in the late 1950s.^[31] Later in Ross's life, this became something of an obsession. In the 1980s, he minimized his role at SofTech to concentrate on developing Plex^[31] into a wide-rangingpseudophilosophy touching on epistemology, ontology, and philosophy of science.^[32] Ross wrote a wealth of material on Plex,^[31] delivering lectures at conferences and holding an abortive seminar at MIT in 1984.^[32] However, he was unable to find the audience he believed Plex deserved, and by the late 1980s he considered it an "intolerable burden of responsibility"^[31] to be its sole proponent and prophet.

• Semi-Automatic Ground Environment

Ross wrote dozens of articles and some reports.^[33] A selection:

• Ross, Douglas T. (1961)."Computer-aided design".Communications of the ACM.4 (5): 235.doi:10.1145/366532.366554.S2CID 1266004.
• Ross, Douglas T. (1961). "A generalized technique for symbol manipulation and numerical calculation".Communications of the ACM.4 (3):147–150.doi:10.1145/366199.366256.S2CID 17097487.
• Ross, Douglas Taylor; Ward, John Erwin (1968)."Investigations in computer-aided design for numerically controlled production"(PDF). Electronic Systems Laboratory, Electrical Engineering Department, Massachusetts Institute of Technology.{{cite journal}}:Cite journal requires|journal= (help)
• Ross, Douglas T.; Johnson, Walter L.; Porter, James H.; Ackley, Stephanie I. (1968)."Automatic generation of efficient lexical processors using finite state techniques".Communications of the ACM.11 (12):805–813.doi:10.1145/364175.364185.S2CID 17253809.
• Ross, Douglas T.; Goodenough, John B.; Irvine, C. A. (1975). "Software engineering: process, principles, and goals".IEEE Computer.8 (5):17–27.doi:10.1109/C-M.1975.218952.S2CID 206566975.
• Ross, Douglas T.; Schoman, Kenneth E. Jr. (1976). "Structured Analysis for Requirements Definition".ICSE: 1.
• "Toward Foundations for the Understanding of Type".Conference on Data: Abstraction, Definition and Structure:63–65. 1976.
• Ross, Douglas T.; Schoman, Kenneth E. Jr. (1977). "Structured Analysis for Requirements Definition".IEEE Transactions on Software Engineering.3 (1):6–15.doi:10.1109/TSE.1977.229899.S2CID 2407903.
• Ross, Douglas T. (1977)."Structured Analysis (SA): A Language for Communicating Ideas"(PDF).IEEE Transactions on Software Engineering.3 (1):16–34.doi:10.1109/TSE.1977.229900.S2CID 17126376.
• Ross, Douglas T. (August 1978)."Origins of the APT Language for Automatically Programmed Tools".ACM SIGPLAN Notices.13 (8):61–99.doi:10.1145/960118.808374.S2CID 17069101.
• Ross, Douglas T. (1980). "Removing the limitations of natural language (with the principles behind the RSA language)". In Freeman, H.; Lewis, P.M. (eds.).Software Engineering. Academic Press.
• Ross, Douglas T. (1985). "Applications and Extensions of SADT".IEEE Computer.18 (4):25–34.doi:10.1109/MC.1985.1662862.S2CID 8174103.
• Ross, Douglas T. (1988). "Foreword to David Marca and Clement McGowan, SADT Structured Analysis and Design Technique". McGraw-Hill.{{cite journal}}:Cite journal requires|journal= (help)
• Ross, Douglas T. (1989). "The NATO Conferences from the Perspective of an Active Software Engineer".International Conference on Software Engineering (ICSE):101–102.

Wikiquote has quotations related toDouglas T. Ross.

• Three oral history interviews with Douglas T. Ross,Charles Babbage Institute, University of Minnesota,21 February 1984,1 November 1989 and7 May 2004.
• Oral history SiggraphSam Matsa
• Douglas T. Ross papers, MC 414. Massachusetts Institute of Technology,Institute Archives and Special Collections, Cambridge, Massachusetts.

• 1929 births
• 2007 deaths
• American computer scientists
• MIT School of Engineering faculty
• Oberlin College alumni
• MIT School of Engineering alumni
• American chief executives
• People from Canandaigua, New York
• American expatriates in China
• Scientists from New York (state)

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