I read all the reviews I could find before buying this book, and they lead me to believe that I could find the help I needed to write a small program to control a bank of DVD players via RS232. Needless to say, this book gave me a lot of VERY useful serial bus information, especially on the "MSComm" Visual Basic serial port control. Chapter 4 gave me all the tips and hints I needed to "hack" together a first-draft application in under a day's work of coding!