A development subsystem is used to develop developer having semiconductive
carrier particles and toner particles. The development subsystem includes
a developer housing, for retaining a quantity of developer having
semiconductive carrier particles and toner particles, a first magnetic
roll having a stationary core with at least one magnet and a sleeve that
rotates about the stationary core of the first magnetic roll, a second
magnetic roll having a stationary core with at least one magnet and a
sleeve that rotates about the stationary core of the second magnetic
roll, and a motor coupled to the first and the second magnetic rolls to
drive the rotating sleeves of the first and the second magnetic rolls in
a direction that is against the direction of a photoreceptor that rotates
in proximity to the first and the second magnetic rolls. The first and
the second magnetic rolls carry semiconductive carrier particles and
toner particles through a development zone formed by the first and the
second magnetic rolls.