Operating system issues for PDAs

Personal digit assistants (PDAs) are small, mobile computing devices whose functionality ranges somewhere between that of an electronic organizer and that of a full-function portable computer. Since PDAs are too small in size to be used for extended work sessions they must justify their existence mostly by providing services that are tailored to people on the go. However, we observe that PDAs are also starting to acquire the ability to communicate and believe that in the long run much of their value will come from being able to interact with external services and devices. The goal of the paper is to relate a view of the ways in which operating systems for this new breed of small ubiquitous computing device will be different from the operating systems of today. The viewpoint is based partly on thoughts about what a ubiquitous computing world will look like and partly on experience with building and using various parts of a ubiquitous computing testbed. In particular, ParcTab computers and ParcPad notebook computers. Both are stylus-based and have onboard communications facilities.<>