HISTORY
The history of
computer development is often referred to in reference to the different generations of computing
devices.
Each of the five generations of computers is characterized by a major
technological development that fundamentally changed the way computers
operate, resulting in increasingly smaller, cheaper, more powerful and
more efficient and reliable computing devices.
In this Webopedia reference article you'll learn about each of the
five generations of computers and the technology developments that have
led to the current devices that we use today. Our journey starts in 1940
with vacuum tube circuitry and goes to the present day -- and beyond
-- with artificial intelligence.
COMPUTER GENERATION
First Generation (1940-1956) Vacuum Tubes
The first computers used vacuum tubes for circuitry and
magnetic drums for
memory,
and were often enormous, taking up entire rooms. They were very
expensive to operate and in addition to using a great deal of
electricity, generated a lot of heat, which was often the cause of
malfunctions.
First generation computers relied on
machine language,
the lowest-level programming language understood by computers, to
perform operations, and they could only solve one problem at a time.
Input was based on punched cards and paper tape, and output was
displayed on printouts.
The UNIVAC and
ENIAC
computers are examples of first-generation computing devices. The
UNIVAC was the first commercial computer delivered to a business client,
the U.S. Census Bureau in 1951.
A UNIVAC computer at the Census Bureau.
Image Source: United States Census Bureau
Second Generation (1956-1963) Transistors
Transistors
replaced vacuum tubes and ushered in the second generation of
computers. The transistor was invented in 1947 but did not see
widespread use in computers until the late 1950s. The transistor was far
superior to the vacuum tube, allowing computers to become smaller,
faster, cheaper, more energy-efficient and more reliable than their
first-generation predecessors. Though the transistor still generated a
great deal of heat that subjected the computer to damage, it was a vast
improvement over the vacuum tube. Second-generation computers still
relied on punched cards for input and printouts for output.
Second-generation computers moved from cryptic
binary machine language to symbolic, or
assembly, languages, which allowed programmers to specify instructions in words.
High-level programming languages were also being developed at this time, such as early versions of
COBOL and
FORTRAN.
These were also the first computers that stored their instructions in
their memory, which moved from a magnetic drum to magnetic core
technology.
The first computers of this generation were developed for the atomic energy industry.
Third Generation (1964-1971) Integrated Circuits
The development of the
integrated circuit was the hallmark of the third generation of computers. Transistors were miniaturized and placed on
silicon chips, called
semiconductors, which drastically increased the speed and efficiency of computers.
Instead of punched cards and printouts, users interacted with third generation computers through
keyboards and
monitors and
interfaced with an
operating system, which allowed the device to run many different
applications
at one time with a central program that monitored the memory. Computers
for the first time became accessible to a mass audience because they
were smaller and cheaper than their predecessors.
Fourth Generation (1971-Present) Microprocessors
The
microprocessor
brought the fourth generation of computers, as thousands of integrated
circuits were built onto a single silicon chip. What in the first
generation filled an entire room could now fit in the palm of the hand.
The Intel 4004 chip, developed in 1971, located all the components of
the computer—from the
central processing unit and memory to input/output controls—on a single chip.
In 1981
IBM introduced its first computer for the home user, and in 1984
Apple
introduced the Macintosh. Microprocessors also moved out of the realm
of desktop computers and into many areas of life as more and more
everyday products began to use microprocessors.
As these small computers became more powerful, they could be linked
together to form networks, which eventually led to the development of
the Internet. Fourth generation computers also saw the development of
GUIs, the
mouse and
handheld devices.
Fifth Generation (Present and Beyond) Artificial Intelligence
Fifth generation computing devices, based on
artificial intelligence, are still in development, though there are some applications, such as
voice recognition, that are being used today. The use of
parallel processing and superconductors is helping to make artificial intelligence a reality.
Quantum computation and molecular and
nanotechnology
will radically change the face of computers in years to come. The goal
of fifth-generation computing is to develop devices that respond to
natural language input and are capable of learning and self-organization.