It has been five years now since Seymour Cray, a mythic figure even while alive, passed away as a result of an automobile accident in the Colorado Rockies. With Cray went the point man for the U.S. high performance computing community, an advocate for building the fastest machine possible at any time, a father figure to aspiring engineers, an Olympian straddling enormous funding requirements and demanding design challenges, in short, the Mozart of MIPS. The machine that established this reputation was the Control Data 6600.
Detailed explication of the design and rationale that went into building the CDC 6/7xxx instruction set, and probably one of the best cohesive books available examining a real computer architecture, especially for it's early date of publication.