  The Oslo rice pile model is a sandpile-like paradigmatic model of
``Self-Organized Criticality'' (SOC). In this paper it is shown that the Oslo
model is in fact exactly a discrete realization of the much studied quenched
Edwards-Wilkinson equation (qEW) [Nattermann et al., J. Phys. II France 2, 1483
(1992)]. This is possible by choosing the correct dynamical variable and
identifying its equation of motion. It establishes for the first time an exact
link between SOC models and the field of interface growth with quenched
disorder. This connection is obviously very encouraging as it suggests that
established theoretical techniques can be brought to bear with full strength on
some of the hitherto elusive problems of SOC.
