A solid-state storage subsystem, such as a non-volatile memory card or drive, includes a main memory area that is accessible via standard memory access commands, and a restricted memory area that is accessible only via one or more non-standard commands. The device may include an electroacoustic speaker transducer connected to the frontal body portion and arrangeable in a sound transmitting relationship to the user’s ear canal when the device is carried by the human user. Under the OPZ constraint, and for scheduling policies under which the number of zones assigned to each RBM is fixed, the power and scheduling sub-problems are decoupled. As product from upstream is delivered to the inner path of the accumulator conveyor, it eventually travels to the outer path and then accumulates inwardly, such that the earlier delivered product remains substantially at the outer path, where a product guide generally directs product on the outermost paths to the downstream destination.