From the very beginning, the theory of base isolation rested on two pillars: "heavy damping" and "frequency separation". Unfortunately, nobody paid any attention that the heavy damping was a sort of a strong connection between a "substructure" and "superstructure", and that the idea of decoupling them with the help of such connections was of no good. Anyway, to virtually test-drive any design concept of base isolation, some online help is available now.