  Vortices in a narrow superconducting strip with a square array of pinning
sites are studied. The interactions of vortices with other vortices and with
external sources (applied magnetic field and transport current) are calculated
via a screened Coulomb model. The edge barrier is taken into account and shown
to have an important role on the system dynamics. Numerical simulations in this
approach show that the field dependent magnetic moment presents peaks
corresponding to history dependent configurations of the vortex lattice. Some
effects of the edge barrier on the I-V characteristics are also reported.
