Dear Christophe, To run getdp-0.83 correctly for my acoustic wave equation, it seems I need to turn the scaling off in solver.par. I tried it on Linux. Is it the case for any other operating system and any other problem? Is there an explaination on how to choose the various parameters in solver.par? Thanks. Lin Ji -- Dept. of Math., RPI 518-276,6904 (work) 518-271,4486 (home)