An electronic apparatus includes a first body, a second body, a keyboard, at least one pair of body linkages and at least one pair of keyboard linkages. A visual axis of the eye is aligned with an instrument axis of an ophthalmic instrument. A desired degree of microetch is provided on an aluminosilicate glass disk substrate, for example, by immersion for 2-4 hours at 360\xb0 C. The discharge mouths of the tubes open into the oven chamber at the suction side of recirculation fans operating within the oven. Adapted leading edge blanking time maybe provided by modifying a conventional leading edge blanking timer in which a fixed voltage reference source is replaced with a variable voltage reference source, the variable voltage reference being dependent upon power requirements on a secondary side of the SMPS. The RRAM includes a lower electrode, a solid solution layer on the lower electrode, a resistive layer on the solid solution layer, and an upper electrode on the resistive layer.