Artifact Details


Gear, Bill (C.W.) SIAM oral history

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Numerical analyst Bill Gear discusses his entire career to date. Born in London in 1935, Gear studied mathematics at Peterhouse, Cambridge before winning a fellowship for graduate study in America. He received a PhD in mathematics from the University of Illinois, Urbana-Champaign in 1960, under the direction of Abraham Taub. During this time Gear worked in the Digital Computer Laboratory, collaborating with Don Gillies on the design of ILLIAC II. He discusses in detail the operation of ILLIAC, its applications, and the work of the lab (including his relationships with fellow graduate student Gene Golub and visitor William Kahan). On graduation, Gear returned to England for two years, where he worked at IBM’s laboratory in Hurlsley on computer architecture projects, serving as a representative to the SPREAD committee charged with devising what became the System 360 architecture. Gear then returned to Urbana-Champaign, where he remained until 1990, serving as a professor of computer science and applied mathematics and, from 1985 onward, as head of the computer science department. He supervised twenty two PhD students, including Linda Petzold. Gear is best known for his work on the solution of stiff ordinary differential equations, and he discusses the origins of his interests in this area, the creation of his DIFSUB routine, and the impact of his book “Numerical Initial Value Problems in Ordinary Differential Equations” (1971). He also explores his work in other areas, including seminal contributions to the analysis of differential algebraic equations and in the 1970s, an ambitious system for generalized network simulation. Gear wrote several successful textbooks and was active in ACM’s SIGNUM and SIGRAPH, served as SIAM President and a member of the ACM Council as well as a number of blue ribbon panels and scholarly societies. In 1990 Gear left Illinois, to become one of the founding vice presidents of NEC’s new Research Institute in Princeton, New Jersey. From 1992 until his retirement in 2000 he was president of the institute, and he discusses his work there, the institute’s place within NEC, and its accomplishments and problems.


2005-09-17; 2005-09-18


Gear, Bill (C.W.), subject topic
Haigh, Thomas, subject topic


SIAM and U.S. Department of Energy

Place of Publication

Princeton, NJ, USA


129 p.



Copyright Holder

Computer History Museum




ILLIAC II (Computer); Taub, Abraham Haskel; Digital Computer Lab (DCL); University of Illinois, Urbana-Champaign; Stiff ordinary differential equations; NEC Research Institute; Princeton University; IBM System 360; Mathematical software; DIFSUB; Differential algebraic equations (DAEs)

Collection Title

Society for Industrial and Applied Mathematics (SIAM) oral history collection


Gift of SIAM and the US Department of Energy

Lot Number