A method of direct memory access includes receiving a first notification at a DMA engine that a first list of descriptors has been prepared, each of the descriptors in the list including an instruction for execution by the DMA engine and a link to a succeeding one of the descriptors, except for a final descriptor in the list, which has a null link. One of the frame and the bottom plate includes a plurality of elastically deformable buckling structures, and the other of the frame and the bottom plate includes a plurality of protrusions corresponding to the buckling structures. The tubular body defines a plurality of openings extending through the body on opposite sides of the stop. Players also provide procedure calls to enable content code to load data from media, perform network communications, determine playback environment configurations, access secure non-volatile storage, submit data to CODECs for output, andor perform cryptographic operations. The washing medium is a solution containing sugar, magnesium salt and calcium salt, in pyrogen-free, sterile distilled water.