A storage device structure has two bits of storage per control gate and uses source side injection to provide lower programming current. A developing roller is separatably abutted on the image carder at a developing position to supply toner onto the image carrier to make the latent image visible as a toner image. In one embodiment, the system is comprised of a control member, an air supply member, and bladder members. A plurality of subscribers receives the signal, and measure a signal quality. Lastly, the trade is executed if the bid order is not less than the ask order, and if the buyer is on the list of buyers and the seller is on the list of sellers.