A disk apparatus includes an optical pick-up and a DSP, and irradiates a laser beam onto a recording surface of a disk recording medium by the optical pick-up. Natural language input may be received. The method comprises: acquiring an image of said defect; calculating a probability that said defect corresponds to one of a series of types of defects; if said probability is higher than a threshold value, determining that said defect is a defect of that particular type. 91 mA, providing one or more bitlines configured to consume a maximum average operating current of approximately 0. The reference signal represents a generally exact relation between the wavelength of the light emitted from the source and time. The method includes modifying a magnetic memory cell write current by summing a write current offset to the magnetic memory cell write current, and determining whether writing to a magnetic memory cell with the modified magnetic memory cell write current results in a write error condition.