To execute the program on a UNIX system (running either sh or csh), simply type
ddscat >& ddscat.out &
which will redirect the ``standard output'' to the file ddscat.out, and run the calculation in the background. The sample calculation (8x6x4=192 dipole target, 3 orientations, two incident polarizations, with scattering calculated for 14 distinct scattering directions), requires 1.0 cpu seconds on a Sun Ultra-170 workstation.