The B-right: a μBTRON-specification OS for PDA with an affordable window system

The emergence of telecommunications infrastructures such as the Internet and cellular phones has heightened demands for so-called personal digital assistants (PDAs), with the same ease of use as pocket calculators, and for mobile computing. Attempting to equip hand-held computers with a fully-fledged windowing system, however, runs into major obstacles in terms of hardware resources, battery capacity and the like. At the hand-held computer level, it is impractical to use Windows 95 or other PC windowing systems. In this respect, the BTRON-specification business-oriented operating system (OS), whose specifications have been designed in the TRON project, has the advantage of running on a low-end CPU and uses limited hardware resources, making it well-suited for PDA and mobile computing uses. In particular, the ability to run at a practical level without needing a high-performance CPU means the CPU clock speed can be kept low to minimize power consumption. This makes possible lightweight batteries and longer battery life. We have developed a μBTRON-specification OS, called B-right, modifying the BTRON specifications for PDA use. Evaluations of the OS have shown that it can be used to implement a practical windowing system on a PDA with its many hardware limitations. The results of our work to date are reported