In accordance with the invention, there is provided a magnetic brush laydown/pickup apparatus having a shell surrounding a plurality of alternating pole magnets, said shell and magnets being relatively movable to transport developer mix through a development zone. Developer mix, comprised of toner particles and carrier particles, is selectively supplied to the surface of the shell at a location upstream of a development zone. The developer mix is selectively removed from the surface of the shell at a location downstream of the development zone. Toner particles are selectively stripped from the developer mix on the shell. A control is used to (1) activate the supply and removal of developer mix to and from the shell and deactivate the stripping of toner particles to provide a source of toner particles for laydown in the development zone, and (2) deactivate the supply and removal of developer mix to and from the shell and activate the stripping of toner particles to provide a source of developer mix, substantially depleted of toner particles, for toner particle pickup in the development zone.