  We developed numerical code for calculation of the extragalactic component of
the spectra of leptons, nucleons and $\gamma$-rays resulting from ``top-down''
(non-acceleration) models for the case of uniform and isotropic source
distribution. We explored two different classes of ``top-down'' scenarios: the
wide earlier investigated class of X particles coming from collapse and/or
annihilation of cosmic topological defects (such as cosmic strings, monopoles,
etc.) and the models of super-heavy long-living X particles with lifetime of
the order or much greater than the current Universe age.
