A PARALLEL RUNGE-KUTTA-NYSSTROM CODE FOR Y''=F(T,Y)

A parallel code for the numerical solution of second order ordinary di fferential systems without first derivative is developed, The code is mainly designed for solving large stiff systems with oscillatory solut ions which require only a moderate accuracy, Then it can be specially useful to integrate systems arising from semi-discretization of second order hyperbolic partial derivative equations. The code is designed f or distributed connection, with a ring topology, It is coded in parall el Fortran and uses the communication system EXPRESS. The code is robu st, reliable and efficient, and achieves almost ideal values of speed- up and efficiency; and it is freely available on http://www.unisa.it/b eapat.dir/soft/.