Systems and methods for extending the memory resources of a user device to storage resources andor network resources associated with the user device. A distance and direction between the reference coordinates and the designated coordinates are calculated. An exterior or otherwise-visible surface of the cartridge may be used for display, when the cartridge is in the port, the visible surface being readily observed by the equipment operator. The symbols in the error correction encoded sequence are then rearranged to ensure that the output symbols derived from input pilot symbols are located at regular, predetermined positions.