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ming methods for Babbages computer, and the contemporary com- puter language ADA is named in her honor). In almost all respects, Babbages design is remarkable in how well it foretold the methods and organization of modern electronic computers.The storage of in- formation on cards corresponds to what we now call ROM, read- only memory, and punched cards themselves were used as a primary input medium for electronic computing well into the 1970s. What Babbage called his storecorresponds to RAM, random-access memory, and his millto the CPU, central processing unit, of mod- ern computers.

Most remarkably, Babbages machine included a significant step toward the flexibility needed for machine intelligence, the seed of something extremely powerful: His computer could examine its own work and decide on its next action by means of the conditional jump.In the course of calculation, the machine could compare a given intermediate result to another value; for instance, to determine whether a particular outcome is a positive or a negative number.Then, depending on the answer, the machine could choose among different program paths.This capability greatly enhances computational power. A conditional jump can be used to determine when a calculation has reached a desired accuracy and can be terminated; in statistical analy- sis, to find the largest or smallest of a set of numbers; or, to give a modern example, to decide when to sell a stock as well as a multitude of other applications.

The deeper significance of the jump is that it introduces an ele- ment of machine choice. This is not yet free will, because the pro- grammer must foresee every possible outcome and provide an alternative for each (if not, the computer might find itself paralyzed). Natural intelligence can always surprise us by a completely unfore- seen choice, whereas a conditional jump offers only a menu of known options, one of which must be followed. Still, we do not know in advance which path the computer will select, especially for complex problems, and so the machine can surprise us as well. This kind of choice by an artificial being has a special significance because such a being, acting in response to external data, is interacting with its envi-

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