I have the second edition (there appears to now be a third out!) but re-reading the preface and "what's changed since the first edition" doesn't seem to say what I remembered re: buses (namely, it says nothing at all). It is possibly my professors were referring to a much earlier course/textbook (or that I dreamed the whole thing!). CS: APP is still a pretty useful book, but...not on this topic, it would seem. (in the second edition, the only reference to buses is on a page where they note that as of its publishing, buses are much more complicated and much less exposed to programmers than they once were) - Sophie On Sun, Nov 19, 2017 at 1:10 PM, Noel Chiappa via cctalk < cctalk at classiccmp.org> wrote: