The Keith G. Calkins collection on Sigma systems consists of material documenting the Sigma computers developed and released by Scientific Data Systems (SDS), Xerox, Honeywell, Inc., and Telefile Computer Products. The collection holds records from all of these companies as well as the user groups focused on Sigma machines and their operating systems and software. Included in the collection are program descriptions of software designed for Sigma systems, manuals, maintenance and testing reports, conference proceedings, and records relating to Telefile Computer Products and its user group TeleXchange. Sigma machines were released and operated primarily from 1966 through 1993 and the material in this collection spans 1969 through 1987.

Keith G. Calkins was born in Cadillac, Michigan on February 1, 1958. Most of his education was spent at Andrews University in Berrien Springs, Michigan, where he received a BS in mathematics in 1981, an MS in computer information science in 1982, another BS in physics in 1988, a second MS in interdisciplinary studies (math and physics) in 1996, and a Master of Arts in Teaching (MAT) in 2002. Calkins also attended the University of Notre Dame, receiving an MS in physics in 1996 and a PhD in 2005, also in physics. Calkins' work experience includes consulting for Artware, Telefile, and NASA and working in various teaching roles including at Andrews University as an Associate Professor of Math & Science and at Ferris State University as an Adjunct Instructor in the Department of Physical Sciences.

10.75 Linear feet, 8 record cartons and 1 small box

The Computer History Museum (CHM) can only claim physical ownership of the collection. Users are responsible for satisfying any claims of the copyright holder. Requests for copying and permission to publish, quote, or reproduce any portion of the Computer History Museum's collection must be obtained jointly from both the copyright holder (if applicable) and the Computer History Museum.

The collection is open for research.