  Two numerical algorithms for the computation of eigenvalues of Dirac
operators in lattice gauge theories are described: one is an accelerated
conjugate gradient method, the other one a standard Lanczos method. Results
obtained by Cullum's and Willoughby's variant of the Lanczos method (whose
convergence behaviour is closely linked with the local spectral density) are
presented for euclidean Wilson fermions in quenched and unquenched SU(2) gauge
fields. Complete spectra are determined on lattices up to $8^3 \cdot 12$, and
we derive numerical values for fermionic determinants and results for spectral
densities.
