  We revisit the Virasoro constraints and explore the relation to the Hirota
bilinear equations. We furthermore investigate and provide the solution to
non-homogeneous Virasoro constraints, namely those coming from matrix models
whose domain of integration has boundaries. In particular, we provide the
example of Hermitean matrices with positive eigenvalues in which case one can
find a solution by induction on the rank of the matrix model.
