ABSTRACT
In the previous six chapters we discussed the characteristics common to the vast majority of computer architectures in use today, as well as most histor - ical architectures since the dawn of modern computing in the 1940s. W e could stop at this point, and the typical reader would be prepared to understand, compare, and evaluate most, if not all machines he or she might encounter in at least the first several years (if not mor e) of a car eer in the computing field. It has been said, though, that there is an exception to every rule, and so it is in computer architecture. For all the rules, or at least standard design practices, that we have discussed, there are at least a few exceptions: unique types of computer architectures designed in special ways for special purposes — past, present, and possibly future.
