[en] The SPADE digital computer program has been developed to calculate variable transformations and partial derivatives between property values, which are necessary to solve the mass, momentum and energy conservation laws having pressure and density as the independent property values. The outputs are tables of temperature, sonic velocity and (delta h/delta rho)sub(p) having pressure and density as the independent variables. The results can be stored in the computer files according to user's option. Steam tables having pressure and density as the independent variables are produced as a sample run and are listed in the appendix. (author)