This was a required text for a university OS course. The book was very through in the number of topics it covered. However, I found the way the book was written to be very long winded and difficult to understand. I found myself searching on-line most of the time to find supplemental information. Even on basic concepts I had already read about in the book just so I could fully understand most of the topics. I still have the book today and have found it to be a useless reference. There is absolutely nothing clear and to the point anywhere in this book.