The structure of experimental heavy machine operators assistant system is described. Main part of the system was built using factory made VME modules and programmed in C under OS-9. First version of system was implemented on an excavator while advanced versions are under development. The paper describes the architecture of two versions of the system, starting from the single processing system to multiprocessor (two SBCs) using common VME-bus. For each hardware sketched out the software i.e. description of processes and interprocess communication. Given the outline of the distributed version of the system with fieldbus networking.