anchor.diff:     ! Compute time step as a fraction of dynamic time
      !---------------------------------------------
      dt = 1.e-3_xp
  -   print *, dt
  +   print *, '# Simulation parameters'
  +   print *, '# dt', dt
  +   print *, '# npoints', npoints
  +   print *, '# maxiter', maxiter
   
      !---------------------------------------------
      ! Open files for output, add headers
  
positive.code:       iter = iter + 1
  
        if (mod(iter, dump_freq) == 0) then
           print*, 'Dump!'
           call compute_energy(m, r, v, Ec, Ep, E) ! Compute Ec, Ep, E at t+dt
           call write_dump(una, un, iter, Ec, Ep, E, t, r, v)
        end if
  
negative.code:    close(un)
     close(una)
  
  end program n_body
  