  We derive the Schwinger-Dyson/loop equations for the USp(2k) matrix model
which close among the closed and open Wilson loop variables. These loop
equations exhibit a complete set of the joining and splitting interactions
required for the nonorientable Type I superstrings. The open loops realize the
SO(2n_f) Chan-Paton factor and their linearized loop equations derive the mixed
Dirichlet/Neumann boundary conditions.
