Earliest
computers
The
earliest calculating machine was the abacus, believed to have been invented in
Babylon around 2400 B.C.E.
The abacus was used by many different cultures and civilizations, including the
major advance known as the Chinese abacus from the 2nd Century B.C.E.
The
Chinese developed the South Pointing Chariot in 115 B.C.E. This device featured a
differential gear, later used in modern times to make analog computers in the
mid-20th Century.
The Indian
grammarian Panini wrote the Ashtadhyayi
in the 5th Century B.C.E.
In this work he created 3,959 rules of grammar for India’s Sanskrit language.
This important work is the oldest surviving linguistic book and introduced the
idea of metarules, transformations, and recursions, all of which have important
applications in computer science.
The first
true computers were made with intricate gear systems by the Greeks. These
computers turned out to be too delicate for the technological capabilities of
the time and were abandoned as impractical. The Antikythera mechanism,
discovered in a shipwreck in 1900, is an early mechanical analog computer from
between 150 B.C.E. and 100 B.C.E.. The Antikythera mechanism used a
system of 37 gears to compute the positions of the sun and the moon through the
zodiac on the Egyptian calendar, and possibly also the fixed stars and five
planets known in antiquity (Mercury, Venus, Mars, Jupiter, and Saturn) for any
time in the future or past. The system of gears added and subtracted angular
velocities to compute differentials. The Antikythera mechanism could accurately
predict eclipses and could draw up accurate astrological charts for important
leaders. It is likely that the Antikythera mechanism was based on an
astrological computer created by Archimedes of Syracuse in the 3rd century B.C.E.
The first
digital computers were made by the Inca using ropes and pulleys. Knots in the
ropes served the purpose of binary digits. The Inca had several of these
computers and used them for tax and government records. In addition to keeping
track of taxes, the Inca computers held data bases on all of the resources of
the Inca empire, allowing for efficient allocation of resources in response to
local disasters (storms, drought, earthquakes, etc.). Spanish soldiers acting
on orders of Roman Catholic priests destroyed all but one of the Inca computers
in the mistaken belief that any device that could give accurate information
about distant conditions must be a divination device powered by the Christian
“Devil” (and many modern Luddites continue to view computers as Satanically
possessed devices).
In the
1800s, the first computers were programmable devices for controlling the weaving
machines in the factories of the Industrial Revolution. Created by Charles
Babbage, these early computers used Punch cards as data storage (the cards
contained the control codes for the various patterns). These cards were very
similiar to the famous Hollerinth cards developed later. The first computer
programmer was Lady Ada, for whom the Ada programming language is named.
In 1822
Charles Babbage proposed a difference engine for automated calculating. In 1933
Babbage started work on his Analytical Engine, a mechanical computer with all
of the elements of a modern computer, including control, arithmetic, and
memory, but the technology of the day couldn’t produce gears with enough
precision or reliability to make his computer possible. The Analytical Engine
would have been programmed with Jacquard’s punched cards. Babbage designed the
Difference Engine No.2. Lady Ada Lovelace wrote a program for the Analytical
Engine that would have correctly calculated a sequence of Bernoulli numbers,
but was never able to test her program because the machine wasn’t built.
George
Boole introduced what is now called Boolean algebra in 1854. This branch of
mathematics was essential for creating the complex circuits in modern
electronic digital computers.
In the
1900s, researchers started experimenting with both analog and digital computers
using vacuum tubes. Some of the most successful early computers were analog
computers, capable of performing advanced calculus problems rather quickly. But
the real future of computing was digital rather than analog. Building on the
technology and math used for telephone and telegraph switching networks,
researchers started building the first electronic digital computers.
The first
modern computer was the German Zuse computer (Z3) in 1941. In 1944 Howard Aiken
of Harvard University created the Harvard Mark I and Mark II. The Mark I was
primarily mechanical, while the Mark II was primarily based on reed relays.
Telephone and telegraph companies had been using reed relays for the logic
circuits needed for large scale switching networks.
The first
modern electronic computer was the ENIAC in 1946, using 18,000 vacuum tubes.
See below for information on Von Neumann’s important contributions.
The first
solid-state (or transistor) computer was the TRADIC, built at Bell Laboratories
in 1954. The transistor had previously been invented at Bell Labs in 1948.