My library is currently selling some of their books that thay have no need of I guess or just depriving us of knowledge for the money. And now and then I look and they have computer books for sale. $0.25 a pop! I already picked some up like pc-dos, qbasic etc ,books I know I can still use. They have books like from 80 etc, I even found one from the 70's. But my question is how old is a book about programming, networking etc, to old to learn from?