Computer history and generations
Each
generation of computer 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 devices.
The history of computer development is often referred to in reference to the
different generations of computing devices. Each of the five generation 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 devices. Learn about
each generation and the developments that led to the current devices that we
use today.
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.
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.
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| Microprocessor |
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.
