Abstract: In a scalable data processing apparatus, particularly a data storage apparatus, one or more thin-film devices which form a substantially planar layer comprise a plurality of sublayers of thin film. Two or more thin-film devices are provided as an integrated stack of the substantially planar layers which form the thin-film devices, such that the apparatus thereby forms a stacked configuration. Each thin-film device comprises one or more memory areas which form matrix addressable memories and additionally circuit areas which form electronic thin-film circuitry for controlling, driving and addressing memory cells in one or more memories. Each memory device has an interface to every other thin-film device in the apparatus, said interfaces being realized with communication and signal lines as well as supporting circuitry for processing extending vertically through dedicated interface areas in the thin-film device.