Poolpo—A Pool of Processors for Process Control Applications

The Poolpo of Brown, Boveri & Company (BBC) Research Center is an experimental multiprocessor that was built to test the validity of the concept of a pool of processors in the process control field. It is a tightly coupled multiprocessor which consists of 9 processors (LSI-1l) sharing a common memory by means of a high-speed bus (an early prototype of the IEEE P896 backplane bus). The processors are interchangeable and can be configured into "dynamic pools," in which tasks can change their processor during their lifetime. The real-time multitasking operating system kernel has been completely written in Modula 2 under RT-11, following the EWICS-TC8 reference model. This paper describes the experiences with this project and draws conclusions about the industrial applications of multiprocessors in general and of the pool structure in particular.