We use AS/400 at work. We are upgrading from our ancient machines and putting AS/400 on our PC's. Our controller is the only one who REALLY knows how AS/400 works. I mean I can use it daily... but I want to really learn it. He is retiring in December... and I'm graduating college with my business degree in December. If I learn this... I'll be a shoe in for that position. I want to buy a book to kind of teach me the main points of it. Does anyone have any to recommend?