History of computer
The abacus was an early ald for mathematical computations.
Its only value is that it aids the memory of the human performing the
calculation. A skilled abacus operator can work on addition and subtraction
problems at the speed of a person equipped with a hand calculator (multiplication
and division are slower). The abacus is often wrongly attributed to China. In
fact, the oldest surviving abacus was used in 300 B.C. by the Babylonians. The
abacus is still in use today, principally in the Far East. A modern abacus
consists of rings that slide over rods, but the older one pictured below dates
from the time when pebbles were used for counting (the word “calculus” comes
from the Latin word for pebble).
In 1642 Blaise Pascal. At age 19, invented the pascaline as
an aid for his father who was a tax collector. Pascal built 50 of this
gear-driven one function calculator (it could only add) but couldn’t sell many
because of their exorbitant cost and because they really weren’t that accurate
(at that time it was not possible to fabricate gears with the required
precision), Up until the present age when car dashboards went digital, the
odometer portion of a car’s speedometer used the very same mechanism as the
Pascaline to increment the next wheel after each full revolution of the prior
wheel.
By 1822 the English mathematician Charles Babbage was
proposing a steam driven calculating machine the size of a room, which he
called the Difference Engine. This machine would be able to compute tables of
numbers, such as logarithm tables. He obtained government funding for this
project due to the importance of numeric tables in ocean promoting their
commercial and military navies, the British government had managed to become
the earth’s greatest empire. But in that time frame the British government was
publishing a a seven volume set of navigation tables which a came with a
companion volume of corrections which showed that the set had over 1000
numerical errors. It was hoped that Babbage’s machine could eliminate errors in
these types of tables. But construction of Babbage’s Difference Engine proved
exceedingly difficult and the project soon became the most expensive government
funded project up to that point in English history.
Hollerith’s invention, known as the Hollerith desk,
consisted of a card reader which sensed the holes in the cards, a gear driven
mechanism which could count (using Pascal’s mechanism which we still see in car
odometers), and a large wall of dial indicators (a car speedometer is a dial
indicator) to display the results of the count.
Hollerith’s technique was successful and the 1890 census was
completed in only 3 years at a savings of 5 million dollars. Hollerith built a
company, the Tabulating Machine Company which, after a few buyouts, eventually
became International Business Machines, known today as IBM. IBM grew rapidly
and punched cards became ubiquitous.
ENIAC
Electronic Numerical Integrator and Calculator (ENIAC) The
title of forefather of today’s all-electronic digital computers is usually
awarded to ENIAC, which stood for Electronic Numerical Integrator and
Calculator. ENIAC
Was built at the University of Pennsylvania between 1943 and
1945 by two professors, John Mauchly and the 24 year old J. Presper Eckert.
ENIAC filled a 20 by 40 foot room, weighed 30
Tons, and used more than 18.000 vacuum tubes. When
operating, the ENIAC was silent but you knew it was on as the 18,000 vacuum
tubes each generated waste heat like a light bulb and all this heat (174,000
watts of heat) meant that the computer could only be operated in a specially
designed room with its own heavy duty air conditioning system.
EDVAC
Eckert and Mauchly’s next teamed up with the mathematician
John von Neumann to design EDVAC, which pioneered the stored program. Because
he was the first to publish a description of this new computer, von Neumann is
often wrongly credited with the realization that the program (that is, the
sequence of computation steps) could be represented electronically just as the
data was. But this major breakthrough can be found in Eckert’s notes long
before he ever started working with von Neumann.
UNIVAC
Universal Automatic Computer (UNIVAC) By the end of the
1950’s computers were no longer one-of-a-kind hand built devices owned only by
universities and government research labs. Eckert and Mauchly left the
University of Pennsylvania over a dispute about who owned the patents for their
invention. They decided to set up their own company. Their first product was
the famous UNIVAC computer, the first commercial (that is, mass produced)
computer. In the 50’s, UNIVAC (a contraction of “Universal Automatic Computer”)
was the household word for “computer” just as “Kleenex” is for “tissue. The
first UNIVAC was sold, appropriately enough, to the Census bureau. UNIVAC was
also the first computer to employ magnetic tape
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