A bio-inspired model for an analog parallel array processor (APAP), based on studies on the vertebrate retina, permits the realization of complex spatio-temporal dynamics in VLSI. This model mimics the way in which images are processed in the natural visual pathway which renders a feasible alternative for the implementation of early vision tasks in standard technologies. A prototype chip has been designed and fabricated in 0.5 /spl mu/m CMOS. Design challenges, trade-offs and the building blocks of such a high-complexity system (0.5/spl times/10/sup 6/ transistors, most of them operating in analog mode) are presented in this paper.