Real time multiprocessor system having a write only data link connected to one of the ports of the memory of each of the processor nodes

A real time data processing system consisting of a plurality of processing nodes and a write only reflective data link for transferring information containing writes only between the plurality or processing nodes. All the nodes include a bus, a processor coupled to the bus, a memory having at least two ports with one port connected to the bus and the other port connected to the data link and a sensor for sensing a write to the memory. At least one node has a VMEbus as the bus and serves as an I/O connected to one port of the memory. Further a local bus included for inputting and outputting from the memory. The local bus is connected to a third port of the memory.