Overview

During the entire 70 years of computer development, a huge variety of discrete and embedded processor species have emerged, evolved, and sometimes died out. Many strange and wonderful designs resulted from this evolution. Sometimes these strange and wonderful concepts lived on, some died out almost immediately, and some lived for only a short while only to die off and then reappear as their gene lines re-emerged in later species.

This chapter surveys thirteen failed processor species (a baker s dozen) and explores the major design errors that caused their demise. Each major design mistake is also illuminated with examples. However, given the endless recycling of many old ideas as technology makes them shiny, bright, and new once again, who knows when the intrepid explorer/designer will next meet up with a descendent of one of these species?

To honor the fact that these species may be thought of as dinosaurs, we solicited from our colleagues suggestions for good saurian-style names for each one. However, the analogy with dinosaurs also holds in another sense: many processors based on these concepts were the dominant species of their day, or had sufficiently bright coloring and loud roaring to attract a huge amount of attention. Just because the evolving world caused a corollary evolution and die-out of our processor species does not mean that a processor species was not a reasonable adaptation to the world as it existed during their heyday.