| Since earliest times human beings have
used numbers. Even the most primitive tribes made complex calculations that were needed
for agriculture, trade, and navigation. Devices to help with such calculations began with
the prehistoric use of stone counters and progressed with the abacus. Not until the
seventeenth century did German and French tinkerers invent a better instrument, the first
adding machine that functioned with interlocking cogs and wheels. In the nineteenth
century, English- man Charles Babbage designed a steam- powered machine that could
calculate square roots,cube roots, and other exponential functions. Although Babbage never
developed this "Analytical Engine" beyond the model stage, he applied many of
the same principles used in modern computers.
With the
advent of electricity came electric calculators based on punched cards and relays. The
first modern computer was not the work of any one person but the result of experiments of
the 1930s and 1940s in England, the United States, and Germany. The Electronic Numerical
Integrator and Computer, or ENIAC, built in 1946 with vacuum tubes at the University of
Pennsyl- vania in the United States, is the best-known early computer.
In the
last 50 years, computers have entered daily life in more ways than people ever could have
imagined. This book will examine how these machines work, with a look in this chapter at
the ingenious inventions that led the way to computer. |
