Aimed at novices as well as professional circuit designers this book is a unique combination of a basic guide to general analog circuit simulation and a SPICE OPUS software manual. The book is divided into three parts: mathematical theory of circuit analysis a crash course on SPICE OPUS and a complete SPICE OPUS reference guide. All simulations as well as the free simulator software may be directly downloaded from the SPICE OPUS homepage: www.spiceopus.si.