The authors offer a synthesis method of state observers with high-order astatism. There are no errors caused by the action of arbitrary external disturbances in reduced variables of such observers. The observers also restore the instantaneous values of disturbances. The authors present a calculation method of ultimate realizable dynamics of observers during their realization in microprocessor control system which calculates in numbers with fixed point without overflowing of variables. The description of experimental installation and software is given.