  We consider the supergravity solution describing a configuration of
intersecting D-4-branes with non-vanishing worldvolume gauge fields. The
entropy of such a black hole is calculated in terms of the D-branes quantised
charges. The non-extreme solution is also considered and the corresponding
thermodynamical quantities are calculated in terms of a D-brane/anti-D-brane
system. To perform the quantum mechanical D-brane analysis we study
open-strings with their ends on branes with a magnetic condensate. Applying the
results to our D-brane system we managed to have a perfect agreement between
the D-brane entropy counting and the corresponding semi-classical result. The
Landau degeneracy of the open string states describing the excitations of the
D-brane system enters in a crucial way. We also derive the near-extreme results
which agree with the semi-classical calculations.
