Closed environments dominated the computing world of the 1970s and early '80s. An operating system written for a Hewlett-Packard computer ran only on H.P. computers; I.B.M. controlled its software from chips up to the user interfaces.

Ellen Ullman’s quote describes the closed environments that dominated the computing world during the 1970s and early 1980s. In this period, technology companies often developed systems that were proprietary, meaning that the software or operating systems they created would only function on their own hardware. For example, an operating system designed for a Hewlett-Packard (HP) computer would not be compatible with any other brand, highlighting the lack of interoperability among different companies' products.

The quote also mentions I.B.M., one of the most influential companies of the time, which controlled the entire software ecosystem, from the chips that powered the computers to the user interfaces people interacted with. This centralized control by major corporations like I.B.M. reinforced the closed systems, creating a landscape where consumers and businesses were locked into using specific products that worked only within a given ecosystem.

Ullman’s reflection points to a time before the open systems and interoperability we often take for granted today. Companies like I.B.M. and HP tightly controlled the computing market, which limited innovation and flexibility for users. These closed systems set the stage for later technological revolutions, such as the rise of open-source software and more collaborative computing environments.

This historical context of the 1970s and 1980s shows how the computing world was shaped by dominant players who controlled not just the hardware but also the software, thus dictating the technological landscape. Ullman’s quote highlights the evolution of the industry and the increasing demand for more openness and flexibility in computing environments.