  In ordinary turbulence research it has been a long standing tradition to
solve the equations in spectral space giving the best possible accuracy. This
is indeed a natural choice for incompressible problems with periodic
boundaries, but it is no longer optimal in many astrophysical circumstances. It
is argued that lower order spatial derivatives schemes are unacceptable in view
of their low overall accuracy, even when mass, momentum, and energy are
conserved to machine accuracy. High order finite difference schemes are
therefore found to be quite efficient and physically appropriate. They are also
easily and efficiently implemented on massively parallel computers. High order
schemes also yield sufficient overall accuracy. Our code uses centered finite
differences which make the adaptation to other problems simple. Since the code
is not written in conservative form, conservation of mass, energy and momentum
can be used to monitor to quality of the solution. A third order Runge-Kutta
scheme with 2N-storage is used for calculating the time advance.
