Charles Petzold was mentioned yesterday in a New York Times Magazine article, “ Stuff We Like That Maybe You Won’t .” Someone on the staff and contributing to the article said, My friends are (mostly) not interested in the history of electrical engineering, which is the subject of Charles Petzold’s “Code.” I find it gripping! We’re pretty sure many of you find the book gripping, too. Tell us about it. Is it a guilty pleasure? A thriller, as Charles builds his explanations, switch by switch, diagram by diagram? A book you give to friends and never get back?  If you’re unfamiliar with Charles’s classic, here’s a description: What do flashlights, the British invasion, black cats, and seesaws have to do with computers? In CODE: The Hidden Language of Computer Hardware and Software, they show more