The part of the book I liked most comes in the section that describes how to connect serial devices. Axelson covers not only RS-232 communications but also RS-485, a serial standard that allows for party-line or multi-drop connections. You would spend a lot of time looking for all the information that the book collects in one place. If you plan to use a serial port in any sort of application, buy this book. It should go on your bookshelf alongside Axelson's earlier book, Parallel Port Complete.