I read the first edition of On The Edge when it first came out and enjoyed it although it really could have stood a good spell checking. What I'm curious about is why the second edition warrants a new name. From what I gather, it's the same book with some added information rather than a new book.
On, and here's an interesting thing about the North American version of Digital Retro. The cover is different. I'd have to pull my copy out to tell you what is on the cover but a 64 it ain't.