According to one embodiment, an information storage medium includes an organic dye material which records information with a light beam having a wavelength equal to or smaller than 620 nm. The transmitter transmits the data in frames which include at least one block. Both the first processing entity and the second processing entity are configured to receive first and second batches of primitives, and a barrier command in between the first and second batches of primitives. In an alternative embodiment, the silicon oxide layer overlying the portion of the substrate is removed with the metal layer abutting the silicon layer. This process yields a relatively benign liquid solution together with vapors which can be drained and vented, respectively, when convenient to the operator. The barb projects above the outer surface of the other of the insertable portions in the adjacent position of the insertable portions so that with the insertable portions in a slit in the cleaning pad the barb will engage the cleaning pad.