History of Numerical Analysis


Oral Histories





Charles Johnson

Oral History (pdf)

Interviewer Thomas Haigh

Charles W. Johnson discusses his career in computing and mathematics with particular attention to his role as cofounder and chairman of IMSL, one of the leading commercial suppliers of mathematical software libraries. Johnson received an undergraduate degree in engineering from the University of Wisconsin, Madison and a masters degree from MIT, graduating in 1955, where he was exposed to the Whirlwind computer. After a two year spell working as a computer center manager for the Army Corps of Engineers, and a brief interregnum with his father’s construction company, he went to work for IBM in Milwaukee as a representative of its Applied Science department. In 1970 he became co-founder of  IMSL (along with his IBM colleague Ed Battiste, and its main investor). Although Johnson’s role with IMSL was that of chairman and financial backer rather than employee, for most of the next thirty five years IMSL was his main preoccupation. He discusses its founding, development and growth, sales strategies, and its key staff members. Johnson also discusses the firm’s change of direction in the 1990s, as it merged with Precision Visuals Incorporated, changed its senior management team and eventually relocated to California. Johnson concludes the interview with a review of his activities as an investor and philanthropist, including involvement with MIT and the Mayo Clinic.

Key words: Whirlwind computer, mathematical software libraries, IMSL (now Visual Numerics), NAG (Numerical Algoriothms Group), MATLAB, SPSS, SAS

Time frame:1950's, 1960's, 1970's

People: Ed Battiste, Walt Gregory, Olin Johnson, W. J. Cody, Jim Pool, Cleve Moler, James Gentle, Margaret Journey

Location: University of  Wisconsin; MIT; Army Corps of Engineers Research and Development Center, Fort Belvoir;  IBM (Milwaukee), IMSL - Houston, TX; Precision Visuals Inc.- Boulder CO.

Citation: Charles Johnson Oral history interview by Thomas Haigh, 25 August, 2004, Racine, Wisconsin. Society for Industrial and Applied Mathematics, Philadelphia, PA

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