The origins of modularity in early computer designs

This working paper is a chapter of the forthcoming book, Design Rules: the Power of Modularity. In the twenty years from 1945 until 1965 computer designers in many different companies developed a long line of products that brought computer technology into significant application in business, science, and government. IBM's System/360 was a watershed event in this process. We have already seen how the project made system modularity a reality thereby solving important problems for users and designers. But System/360 also had a profound effect on the nature of future computer designs and developments. In this chapter the authors lay the ground work for their theory of design evolution.