Computer
Hardware Question 1: What is Computer hardware?
Answer: Computer hardware refers to
the computer's machinery, its electronic devices and its circuits. What we call
a computer is actually a system, a combination of components that
work together. The hardware devices are the physical components of that system.
The hardware is designed to work hand-in-hand with computer programs, referred
to as software. Software programs are usually designed
specifically for use with one type of computer hardware.
Answer: Saying exactly when the computer came into
existence is a little tricky because there were a number of devices and
concepts that had to be invented first. The first computers, developed during
World War II, were used for mathematical calculations. Although electronic
computers have been in existence since then, people have always had a need to
manage information and to solve problems. Early thinkers created a number of
devices to evaluate information and to solve problems related to that
information. One of the earliest known devices, the abacus,
was a computational tool that was used to quickly add and subtract numbers. It
has been in use in China for thousands of years and is still used in everyday
transactions throughout the Far East.
Another computational device, known
as Napier's Bones, is similar in design to the abacus. Designed by John
Napier in the early 1600s, it was comprised of multiplication tables
inscribed on ivory rods that looked like bones. It was used for mathematical
calculations including multiplication and division and is similar in principle
to the modern slide rule.
Another notable device on the path
to modern computing was invented in 1642 by Blaise Pascal, a French
philosopher and mathematician (the Pascal programming language is also named
after him). Pascal's adding machine used a hand-powered mechanical
system to add and subtract numbers. The system of dealing with numbers in
Pascal's device is similar to the system used in today's computers and it is
worth noting that, at the time, the device was seen as a threat to the livelihood
of those employed to calculate numbers.
Pascal's device was not improved
upon until 40 years later when a German, Gottfried Wilhelm von Leibniz,
developed a device that was not only able to add and subtract, but was also
capable of carrying out multiplication and divisions (as a series of repeated
additions and subtractions).
Another device, the Jacquard loom,
may not, on first analysis, seem related to the early computational devices.
But the French inventor, Joseph Marie Jacquard, developed a device to
automate rug weaving on a loom in 1804. The device used holes punched in cards
to determine the settings for the loom, a task that normally required constant
attention by the loom operator. By using a set of punched cards, the loom could
be "programmed" to weave an entire rug in a complicated pattern. This
system of encoding information by punching a series of holes in paper was to
provide the basis for the data-handling methods that would eventually be used
in the early computers.
Despite the great success of
Jacquard's loom, many were disturbed by this "high tech" invention
when they learned that it could completely eliminate jobs that had been done by
humans for centuries. As a result, in England, a group that called
themselves Luddities smashed some of the automated looms as
a protest against mechanical innovation and the related threat to their jobs.
A few years later, in England, Charles
Babbage proposed the design for a new calculator that was in many ways the
forerunner of today's computers. In 1822, Babbage built a working model of the
difference engine and received a grant from the British government to develop a
full-scale version. Unfortunately, he soon discovered that the parts that he
needed could not be manufactured to tolerances that he required.
In 1842, Ada Augusta Byron,
the daughter of the poet Lord Byron, became interested in Babbage's project.
She was a trained mathematician and saw the potential of his device (the Ada
programming language that is supported by the U.S. Department of Defense
was named after her). She helped provide funds to continue research for the
project and she collaborated with Babbage on some of his scientific writings.
Today she is credited with coming up with the concept of a programmed loop, a
way to carry out the sequence of steps that are part of a mathematical
calculation. Based on her published descriptions of the process, many consider
her to be the world's first programmer.
Forty years later, Dr. Herman
Hollerith, an employee of the U.S. Census Bureau, put Jacquard's punched-card
concept together with some of the same kind of ideas that had been proposed by
Charles Babbage and Ada Byron to solve a real-world problem. The Census Bureau
realized that it was taking so long to complete census calculations they
wouldn't even be able to complete one census before it was time to undertake
the next one. Hollerith proposed a solution based on what he termed a census
machine that would count data that was fed in on punched cards. He chose cards
that were about the size of dollar bills to be fed into a hand cranked machine.
Using Hollerith's machine, the census was tabulated in less than half the time
it had previously taken.
Based on his Census Bureau success,
Hollerith formed the Tabulating Machine Company in 1896 and began designing
census tabulation machines. The company eventually evolved into the
International Business Machines (IBM) company, the world's largest computer
company.
Although computational machines
continued to evolve, the invention of modern computers could not come about
until the supporting technologies of electrical switching devices were in
place. By 1937, electricity was in general use in most of the world's cities
and the principles of radio were well understood. Using these new tools,
several researchers were working on electrically powered versions of the
earlier computing devices. Among them was Howard Aiken of Harvard University.
Working with the support of the IBM company, in 1944 he completed the basic
development of a machine that was dubbed the Mark 1. The machine, which
was also known as the Automatic Sequence Controlled Calculator, is now seen as
the first full-sized digital computer (smaller-scale electric
calculating devices had been created earlier). The Mark 1 filled an entire room
and weighed 5 tons, included 500 miles of wiring, and was controlled by punched
paper cards and tapes.
Despite the many advances in
computational technology represented by this new machine, it was very limited
by today's standards. It was used only for numeric calculations and took three
seconds to carry out one multiplication. However, with the world-wide expansion
of industrial technologies that accompanied World War II, others were
proceeding along the same path established by the Mark 1. For example, John
Mauchly and J. Presper Eckert were developing a large-scale
computing device known as the Electronic Numerical Integrator and Calculator (
ENIAC) at the University of Pennsylvania with the support of the
U.S. government. Based on mechanical switches and radio vacuum tubes, this
device is now seen as the first electronic computer. The huge machine consumed
so much power that it often caused the lights in nearby Philadelphia to dim.
But it was far more capable than Aiken's Mark 1 computer: it could perform
thousands of calculations per second and was used for a variety of purposes
including scientific research and weather prediction.
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