  We present results from a fully relativistic Monte Carlo simulation of
diffusive shock acceleration (DSA) in unmodified (i.e., test-particle) shocks.
The computer code uses a single algorithmic sequence to smoothly span the range
from nonrelativistic speeds to fully relativistic shocks of arbitrary
obliquity, providing a powerful consistency check. We show the dependence of
the particle spectrum, which can differ strongly from the canonical f(p)
proportional to p^{-4.23} result, on the obliquity and on the strength and
``fineness'' of scattering for a range of shock Lorentz factors. The Monte
Carlo results are also shown to be consistent with a simple relation for the
spectral index given by Keshet and Waxman (2005) in parallel shocks when the
diffusion is ``fine'' and isotropic.
