I liked Tanenbaum's book but I think I understand what you mean with theory vs application. Back when I was working on my toy OS I also bought the book describ

I liked Tanenbaum's book but I think I understand what you mean with theory vs application. Back when I was working on my toy OS I also bought the book describing the implementation of an OS called MMURTL, apparently the book and the code are now available for free online: http://www.ipdatacorp.com/mmurtl/mmurtlv1.pdf http://www.ipdatacorp.com/mmurtl/mmurtlv1.pdf http://www.ipdatacorp.com/mmurtl/ http://www.ipdatacorp.com/mmurtl/ I liked it and found it quite useful but I remember the folks at alt.os.development being quite negative about it because of the design. Also, Podanoffsky's 'Dissecting DOS' is a good book though obviously focused on, eh DOS.