1. What is claimed is a deterministic real time computing system for use in general or special purpose applications based on a top down hierarchical physical and logical architecture composed of core processing units, with each core processing unit consisting of one communications processing section and one computation control and monitoring processing section that communicate through Dual Port Ram, with the communications processing section consisting of a single processor, with the communications control and monitoring processing section consisting of one or more processors, with all processors running non pre-emptive and non prioritized Round Robin real time operating systems, with all processors using only polling and no interrupts to monitor communication ports or other devices, with all processors using sequential function oriented programming and not object oriented programming, with all processors using single message communication—waiting for a response before sending the next message, with all processors using global variables with limited use of local variables, with all processors using ASCII text for all data and communications, with the two processing sections organized hierarchically with the communications processing section being the master and the computation control and monitoring processing section being the slave, with core processing units also organized in a master slave inverted tree structured hierarchy, with the top level core processing unit communicating with external general purpose computers or serving as the man machine interface, with all intermediate level core processing units performing supervisory control, monitoring and message passage functions, with the computation and control processing sections on an higher intermediate level communicating with one or more communications processors on the next lower level core processing units, with the communications between core processing units being master slave and not peer to peer, and with all core processing units at branch termination points of the tree controlling or monitoring some external device or executing some application