Computers: History And Development Essay, Research Paper
Overview
Nothing epitomizes modern life better
than the computer. For better or worse, computers have infiltrated every
aspect of our society. Today computers do much more than simply compute:
supermarket scanners calculate our grocery bill while keeping store inventory;
computerized telphone switching centers play traffic cop to millions of
calls and keep lines of communication untangled; and automatic teller machines
(ATM) let us conduct banking transactions from virtually anywhere in the
world. But where did all this technology come from and where is it heading?
To fully understand and appreciate the impact computers have on our lives
and promises they hold for the future, it is important to understand their
evolution.
Early Computing Machines and Inventors
The abacus,
which emerged about 5,000 years ago in Asia Minor and is still in use
today, may be considered the first computer. This device allows users
to make computations using a system of sliding beads arranged on a rack.
Early merchants used the abacus to keep trading transactions. But as the
use of paper and pencil spread, particularly in Europe, the abacus lost
its importance. It took nearly 12 centuries, however, for the next significant
advance in computing devices to emerge. In 1642, Blaise
Pascal (1623-1662), the 18-year-old son of a French tax collector,
invented what he called a numerical wheel calculator to help his father
with his duties. This brass rectangular box, also called a Pascaline,
used eight movable dials to add sums up to eight figures long. Pascal’s
device used a base of ten to accomplish this. For example, as one dial
moved ten notches, or one complete revolution, it moved the next dial
– which represented the ten’s column – one place. When the ten’s dial
moved one revolution, the dial representing the hundred’s place moved
one notch and so on. The drawback to the Pascaline, of course, was its
limitation to addition.
In 1694, a German mathematician and philosopher, Gottfried
Wilhem von Leibniz (1646-1716), improved the Pascaline by creating
a machine that could also multiply. Like its predecessor, Leibniz’s mechanical
multiplier worked by a system of gears and dials. Partly by studying Pascal’s
original notes and drawings, Leibniz was able to refine his machine. The
centerpiece of the machine was its stepped-drum gear design, which offered
an elongated version of the simple flat gear. It wasn’t until 1820, however,
that mechanical calculators gained widespread use. Charles Xavier Thomas
de Colmar, a Frenchman, invented a machine that could perform the four
basic arithmetic functions. Colmar’s mechanical calculator, the arithometer,
presented a more practical approach to computing because it could add,
subtract, multiply and divide. With its enhanced versatility, the arithometer
was widely used up until the First World War. Although later inventors
refined Colmar’s calculator, together with fellow inventors Pascal and
Leibniz, he helped define the age of mechanical computation.
The real beginnings of computers as we know them today, however, lay
with an English mathematics professor, Charles
Babbage (1791-1871). Frustrated at the many errors he found while
examining calculations for the Royal Astronomical Society, Babbage declared,
"I wish to God these calculations had been performed by steam!"
With those words, the automation of computers had begun. By 1812, Babbage
noticed a natural harmony between machines and mathematics: machines were
best at performing tasks repeatedly without mistake; while mathematics,
particularly the production of mathematic tables, often required the simple
repetition of steps. The problem centered on applying the ability of machines
to the needs of mathematics. Babbage’s first attempt at solving this problem
was in 1822 when he proposed a machine to perform differential equations,
called a Difference
Engine. Powered by steam and large as a locomotive, the machine would
have a stored program and could perform calculations and print the results
automatically. After working on the Difference Engine for 10 years, Babbage
was suddenly inspired to begin work on the first general-purpose computer,
which he called the Analytical Engine. Babbage’s assistant, Augusta
Ada King, Countess of Lovelace (1815-1842) and daughter of English
was instrumental in the machine’s design. One of the few people who understood
the Engine’s design as well as Babbage, she helped revise plans, secure
funding from the British government, and communicate the specifics of
the Analytical Engine to the public. Also, Lady Lovelace’s fine understanding
of the machine allowed her to create the instruction routines to be fed
into the computer, making her the first female computer programmer. In
the 1980’s, the U.S. Defense Department
named a programming language ADA
in her honor.
Babbage’s steam-powered Engine, although ultimately never constructed,
may seem primitive by today’s standards. However, it outlined the basic
elements of a modern general purpose computer and was a breakthrough concept.
Consisting of over 50,000 components, the basic design of the Analytical
Engine included input devices in the form of perforated cards containing
operating instructions and a "store" for memory of 1,000 numbers
of up to 50 decimal digits long. It also contained a "mill"
with a control unit that allowed processing instructions in any sequence,
and output devices to produce printed results. Babbage borrowed the idea
of punch cards to encode the machine’s instructions from the Jacquard
loom. The loom, produced in 1820 and named after its inventor, Joseph-Marie
Jacquard, used punched boards that controlled the patterns to be woven.
In 1889, an American inventor,
Herman Hollerith (1860-1929), also applied the Jacquard loom concept
to computing. His first task was to find a faster way to compute the U.S.
census. The previous census in 1880 had taken nearly seven years to
count and with an expanding population, the bureau feared it would take
10 years to count the latest census. Unlike Babbage’s idea of using perforated
cards to instruct the machine, Hollerith’s method used cards to store
data information which he fed into a machine that compiled the results
mechanically. Each punch on a card represented one number, and combinations
of two punches represented one letter. As many as 80 variables could be
stored on a single card. Instead of ten years, census takers compiled
their results in just six weeks with Hollerith’s machine. In addition
to their speed, the punch cards served as a storage method for data and
they helped reduce computational errors. Hollerith brought his punch card
reader into the business world, founding Tabulating Machine Company in
1896, later to become International Business
Machines (IBM) in 1924 after a series of mergers. Other companies
such as Remington
Rand and Burroghs also manufactured punch readers for business use.
Both business and government used punch cards for data processing until
the 1960’s.
In the ensuing years, several engineers made other significant advances.
Vannevar
Bush
(1890-1974) developed a calculator for solving differential equations
in 1931. The machine could solve complex differential equations that had
long left scientists and mathematicians baffled. The machine was cumbersome
because hundreds of gears and shafts were required to represent numbers
and their various relationships to each other. To eliminate this bulkiness,
John V. Atanasoff
(b. 1903), a professor at Iowa State College (now called Iowa
State University) and his graduate student, Clifford Berry,
envisioned an all-electronic computer that applied Boolean algebra to
computer circuitry. This approach was based on the mid-19th century work
of George Boole (1815-1864) who clarified the
binary system of algebra, which stated that any mathematical equations
could be stated simply as either true or false. By extending this concept
to electronic circuits in the form of on or off, Atanasoff and Berry had
developed the first all-electronic computer by 1940. Their project, however,
lost its funding and their work was overshadowed by similar developments
by other scientists.
Five Generations of Modern Computers
First Generation (1945-1956)
With the onset of the Second
World War, governments sought to develop computers to exploit their
potential strategic importance. This increased funding for computer development
projects hastened technical progress. By 1941 German engineer Konrad
Zuse had developed a computer, the Z3, to design airplanes
and missiles. The Allied forces, however, made greater strides in developing
powerful computers. In 1943, the British completed a secret code-breaking
computer called Colossus
to decode German
messages. The Colossus’s impact on the development of the computer
industry was rather limited for two important reasons. First, Colossus
was not a general-purpose computer; it was only designed to decode secret
messages. Second, the existence of the machine was kept secret until decades
after the war.
American efforts produced a broader achievement. Howard H. Aiken (1900-1973),
a Harvard engineer working with IBM, succeeded in producing an all-electronic
calculator by 1944. The purpose of the computer was to create ballistic
charts for the U.S. Navy. It was about
half as long as a football field and contained about 500 miles of wiring.
The Harvard-IBM Automatic Sequence Controlled Calculator, or Mark I for
short, was a electronic relay computer. It used electromagnetic signals
to move mechanical parts. The machine was slow (taking 3-5 seconds per
calculation) and inflexible (in that sequences of calculations could not
change); but it could perform basic arithmetic as well as more complex
equations.
Another computer development spurred by the war was the Electronic Numerical
Integrator and Computer (ENIAC),
produced by a partnership between the U.S. government and the University
of Pennsylvania. Consisting of 18,000 vacuum tubes, 70,000 resistors
and 5 million soldered joints, the computer was such a massive piece of
machinery that it consumed 160 kilowatts of electrical power, enough energy
to dim the lights in an entire section of Philadelphia.
Developed by John
Presper Eckert (1919-1995) and John W. Mauchly (1907-1980),
ENIAC, unlike the Colossus and Mark I, was a general-purpose computer
that computed at speeds 1,000 times faster than Mark I.
In the mid-1940’s John
von Neumann (1903-1957) joined the University of Pennsylvania team,
initiating concepts in computer design that remained central to computer
engineering for the next 40 years. Von Neumann designed the Electronic
Discrete Variable Automatic Computer (EDVAC)
in 1945 with a memory to hold both a stored program as well as data. This
"stored memory" technique as well as the "conditional control
transfer," that allowed the computer to be stopped at any point and
then resumed, allowed for greater versatility in computer programming.
The key element to the von Neumann architecture was the central processing
unit, which allowed all computer functions to be coordinated through a
single source. In 1951, the UNIVAC
I (Universal Automatic Computer), built by Remington Rand, became
one of the first commercially available computers to take advantage of
these advances. Both the U.S. Census
Bureau and General Electric owned
UNIVACs. One of UNIVAC’s impressive early achievements was predicting
the winner of the 1952 presidential election, Dwight
D. Eisenhower.
First
generation computers were characterized by the fact that operating instructions
were made-to-order for the specific task for which the computer was to
be used. Each computer had a different binary-coded program called a machine
language that told it how to operate. This made the computer difficult
to program and limited its versatility and speed. Other distinctive features
of first generation computers were the use of vacuum
tubes (responsible for their breathtaking size) and magnetic drums
for data storage.
Second
Generation Computers (1956-1963)
By
1948, the invention of the transistor greatly
changed the computer’s development. The transistor replaced the large,
cumbersome vacuum tube in televisions, radios and computers. As a result,
the size of electronic machinery has been shrinking ever since. The transistor
was at work in the computer by 1956. Coupled with early advances in magnetic-core
memory, transistors led to second generation computers that were smaller,
faster, more reliable and more energy-efficient than their predecessors.
The first large-scale machines to take advantage of this transistor technology
were early supercomputers, Stretch by IBM and LARC by Sperry-Rand. These
computers, both developed for atomic energy laboratories, could handle
an enormous amount of data, a capability much in demand by atomic scientists.
The machines were costly, however, and tended to be too powerful for the
business sector’s computing needs, thereby limiting their attractiveness.
Only two LARCs were ever installed: one in the Lawrence
Radiation Labs in Livermore, California, for which the computer was
named (Livermore Atomic Research Computer) and the other at the U.S.
Navy Research and Development Center in Washington,
D.C. Second generation computers replaced machine language with assembly
language, allowing abbreviated programming codes to replace long, difficult
binary codes.
Throughout the early 1960’s, there were a number of commercially successful
second generation computers used in business, universities, and government
from companies such as Burroughs, Control
Data, Honeywell, IBM, Sperry-Rand,
and others. These second generation computers were also of solid state
design, and contained transistors in place of vacuum tubes. They also
contained all the components we associate with the modern day computer:
printers, tape storage, disk storage, memory, operating systems, and stored
programs. One important example was the IBM 1401, which was universally
accepted throughout industry, and is considered by many to be the Model
T of the computer industry. By 1965, most large business routinely processed
financial information using second generation computers.
It was the stored program and programming language that gave computers
the flexibility to finally be cost effective and productive for business
use. The stored program concept meant that instructions to run a computer
for a specific function (known as a program) were held inside the computer’s
memory, and could quickly be replaced by a different set of instructions
for a different function. A computer could print customer invoices and
minutes later design products or calculate paychecks. More sophisticated
high-level languages such as COBOL
(Common Business-Oriented Language) and FORTRAN
(Formula Translator) came into common use during this time, and have expanded
to the current day. These languages replaced cryptic binary machine code
with words, sentences, and mathematical formulas, making it much easier
to program a computer. New types of careers (programmer, analyst, and
computer systems expert) and the entire software
industry began with second generation computers.
Third Generation Computers (1964-1971)
Though transistors were clearly an improvement over the vacuum tube,
they still generated a great deal of heat, which damaged the computer’s
sensitive internal parts. The quartz rock eliminated this problem.
Jack Kilby, an engineer with Texas
Instruments, developed the integrated circuit (IC) in 1958. The IC
combined three electronic components onto a small silicon disc, which
was made from quartz. Scientists later managed to fit even more components
on a single chip, called a semiconductor. As a result, computers became
ever smaller as more components were squeezed onto the chip. Another third-generation
development included the use of an operating
system that allowed machines to run many different programs at once
with a central program that monitored and coordinated the computer’s memory.
Fourth Generation (1971-Present)
After the integrated circuits, the only place to go was down – in size,
that is. Large scale integration (LSI) could fit hundreds of components
onto one chip. By the 1980’s, very large scale integration (VLSI) squeezed
hundreds of thousands of components onto a chip. Ultra-large scale integration
(ULSI) increased that number into the millions. The ability to fit so
much onto an area about half the size of a U.S. dime helped diminish the
size and price of computers. It also increased their power, efficiency
and reliability. The Intel 4004 chip,
developed in 1971, took the integrated circuit one step further by locating
all the components of a computer (central processing unit, memory, and
input and output controls) on a minuscule chip. Whereas previously the
integrated circuit had had to be manufactured to fit a special purpose,
now one microprocessor could be manufactured and then programmed to meet
any number of demands. Soon everyday household items such as
microwave ovens, television sets and automobiles
with electronic fuel injection
incorporated microprocessors.
Such condensed power allowed everyday people to harness a computer’s
power. They were no longer developed exclusively for large business or
government contracts. By the mid-1970’s, computer manufacturers sought
to bring computers to general consumers. These minicomputers came complete
with user-friendly software packages that offered even non-technical users
an array of applications, most popularly word processing and spreadsheet
programs. Pioneers in this field were Commodore,
Radio Shack and Apple
Computers. In the early 1980’s, arcade
video games such as Pac Man and
home video game systems such as the
Atari 2600 ignited consumer interest for more sophisticated, programmable
home computers.
In 1981, IBM introduced its personal computer (PC) for use in the home,
office and schools. The 1980’s saw an expansion in computer use in all
three arenas as clones of the IBM PC made the personal computer even more
affordable. The number of personal computers in use more than doubled
from 2 million in 1981 to 5.5 million in 1982. Ten years later, 65 million
PCs were being used. Computers continued their trend toward a smaller
size, working their way down from desktop to laptop computers (which could
fit inside a briefcase) to palmtop (able to fit inside a breast pocket).
In direct competition with IBM’s PC was Apple’s Macintosh line, introduced
in 1984. Notable for its user-friendly design, the Macintosh offered an
operating system that allowed users to move screen icons instead of typing
instructions. Users controlled the screen cursor using a mouse, a device
that mimicked the movement of one’s hand on the computer screen.
As computers became more widespread in the workplace, new ways to harness
their potential developed. As smaller computers became more powerful,
they could be linked together, or networked, to share memory space, software,
information and communicate with each other. As opposed to a mainframe
computer, which was one powerful computer that shared time with many terminals
for many applications, networked computers allowed individual computers
to form electronic co-ops. Using either direct wiring, called a Local
Area Network (LAN), or telephone lines, these networks could reach
enormous proportions. A global web of computer circuitry, the Internet,
for example, links computers worldwide into a single network of information.
During the 1992 U.S. presidential election, vice-presidential candidate
Al Gore
promised to make the development of this so-called "information superhighway"
an administrative priority. Though the possibilities envisioned by Gore
and others for such a large network are often years (if not decades) away
from realization, the most popular use today for computer networks such
as the Internet is electronic mail, or E-mail, which allows users to type
in a computer address and send messages through networked terminals across
the office or across the world.
Fifth Generation (Present and Beyond)
Defining the fifth generation of computers is somewhat difficult because
the field is in its infancy. The most famous example of a fifth generation
computer is the fictional HAL9000
from Arthur
C. Clarke’s novel, 2001: A
Space Odyssey. HAL performed all of the functions currently
envisioned for real-life fifth generation computers. With artificial
intelligence, HAL could reason well enough to hold conversations with
its human operators, use visual input, and learn from its own experiences.
(Unfortunately, HAL was a little too human and had a psychotic breakdown,
commandeering a spaceship and killing most humans on board.)
Though the wayward HAL9000 may be far from the reach of real-life computer
designers, many of its functions are not. Using recent engineering advances,
computers are able to accept spoken
word instructions (voice recognition) and imitate human reasoning.
The ability to translate a foreign language is also moderately possible
with fifth generation computers. This feat seemed a simple objective at
first, but appeared much more difficult when programmers realized that
human understanding relies as much on context and meaning as it does on
the simple translation of words.
Many advances in the science of computer design and technology are coming
together to enable the creation of fifth-generation computers. Two such
engineering advances are parallel processing, which replaces von Neumann’s
single central processing unit design with a system harnessing the power
of many CPUs to work as one. Another advance is superconductor
technology, which allows the flow of electricity with little or no resistance,
greatly improving the speed of information flow. Computers today have
some attributes of fifth generation computers. For example, expert systems
assist doctors in making diagnoses by applying the problem-solving steps
a doctor might use in assessing a patient’s needs. It will take several
more years of development before expert systems are in widespread use.
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