This book is excellent at what it's for. It is to help you understand the mechanics behind assembly language. No, it doesn't go into machine cycles for all commands, or explain the minute details. What it does do is explain the Intel proccesor and how it reacts to machine code and memory. After reading the book you can write your own program, though it would not be to useful. But as he says in the book, you'll have a clear understanding when you pick up a more advanced book. You won't be thrown off where others left out detail. He uses alot of metaphores, and even asks some obvious questions for you. It is truly a good book. My only criticism of this book is all the mistakes as the book progresses. There is a example where he wants to explain LEA, and he does, but the program that the sample is from uses OFFSET instead! None-the-less the snippet mentions LEA. Also, an embarrasing mistake, the reference for PUSH gives examples of POP. There are a few more as well. If it wasn't for the mistakes I would give this book a 9 on a scale of ten. The last point being withheld because I thought a few areas could have used more clarification. However, most of these things can be figured out by yourself. Please, don't get me wrong, it is an excellent book, and you'll be very happy that you bought it.