I have read Tanenbaum's book twice. Really great book. Very dense in information but enjoyable as well. That and the Common Lisp Reference Manual were at some point my favorite CS readings. I was reading them in printed form.
Yeah i didn't specify, i think it is the "Modern Operating Systems". I read it in Greek and I don't remember the title, maybe the title was translated a little bit different. It was not the Minix book, i have not read that unfortunately.
Now however, i am sold on the idea of the Lisp Machine. Hopefully some day a lisp OS and hardware will be a viable way to use a computer.