Hardware-software interactions in SYMBOL-2R's operating system

摘要

This paper describes the chief attributes of the Virtual Processor placed at the disposal of each user of the SYMBOL-2R time-shared multiprocessor system, and the mechanisms by which SYMBOL's hardwired operating system manages processing-mode transitions for individual Virtual Processors and allocates hardware resources -- processors and memory space -- among competing Virtual Processors. It describes the provisions by which the unusually high-level capabilities of the hardware are augmented by software, and contrasts the structure of the software component of the operating system with that of the hardware component. Finally, it describes the hardware/software partition of resource-allocation functions, in which allocation policies are controlled by software and executed by hardware.