This paper is directed to those engineers who sense a need for custom integrated circuits, but who are not familiar with the options available to them. Custom integrated circuits are invariably unique to a particular customer. In automotive applications they are seen as interface units between microprocessors and controlled systems, also as independent functional elements. They are used for reasons of economy, reliability and security. The CMOS (Complementary Symmetry Metal Oxide Semiconductor) technology has a number of virtues that make it especially suitable to the automotive environment. A technique exists for rapidly converting conventional logic diagrams into computer-designed custom CMOS integrated circuits. The technique is described.