  We introduce a deterministic self-organized critical system that is one
dimensional and bulk driven. We find that there is no universality class
associated with the system. That is, the critical exponents change as the
parameters of the system are changed. This is in contrast with the boundary
driven version of the model [M. de Sousa Vieira, Phys. Rev. E 61 (2000) 6056]
in which the exponents are unique. This model can be seen as a discretized
version of the conservative limit of the Burridge-Knopoff model for
earthquakes.
