Virtual single machine with message-like hardware interrupts and processor exceptions

Abstract From the Canadian patent

A multi-processor, multi-tasking virtual machine comprises processes, messages, and contexts. Processes communicate only through messages. Contexts are groups of related processes. The virtual machine makes all hardware devices appear to be processes, in that the occurrence of an event on a device causes a message to be generated and sent to another process for handling. The receiving process performs all operations required to handle the event. Thus a variety of hardware devices can be connected and disconnected from the system without interrupting its operation and without necessitating extensive software revisions.