Generations of Computer
Before the
digital computers were invented all mechanical and analog computers are
considered to be the constituent of Mechanical
Era (1623 – 1937). The evolution of digital computing is often divided into generations. Each generation 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. Those recognized generations are:
a. First
Generation (1940-1956). Vacuum tubes were the main component of
these generations. Those 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. The UNIVAC
and ENIAC computers are examples of first-generation computing devices.
b. Second Generation (1956-1963). Transistors were the main
component of this generation. 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 and replaced them, 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 relied on punched cards for
input and printouts for output.
c. Third
Generation (1964-1971). The development of the Integrated Circuit (IC) 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. Computers for the first time became accessible to a mass audience
because they were smaller and cheaper than their predecessors.
d. Fourth Generation (1971-Present). 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 were 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.
e. Fifth Generation
(Present and Beyond)
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 nano-technology 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.
