Nothing epitomizes modern life better than the computer. Computers are such an integral part of our everyday life now most people take them and what they have added to life totally for granted. Even more so the generation who have grown from infancy within the global desktop and laptop revolution since the 1980s. The history of computer development is often referred to in reference to the different generations of computing devices. A generation refers to the state of improvement in the product development process. This term is also used in the different advancements of new computer technology. As new technology was emerging, it was being used in the making of computer. With each new generation, the circuitry has gotten smaller and more advanced than the previous generation before it. As a result of the miniaturization, speed, power, and com- puter memory has proportionally increased. New discoveries are constantly being developed that affect the way we live, work and play.

1. Generation of Computers: A Survey
Nithin Prince John
Department of Computer Science and Engineering
Sree Buddha College Of Engineering, Pattoor, Kerala - 690529
nithinpj09@gmail.com
Abstract—Nothing epitomizes modern life better than the
computer. Computers are such an integral part of our everyday
life now most people take them and what they have added to life
totally for granted. Even more so the generation who have grown
from infancy within the global desktop and laptop revolution
since the 1980s. The history of computer development is often
referred to in reference to the different generations of computing
devices. A generation refers to the state of improvement in the
product development process. This term is also used in the
different advancements of new computer technology. As new
technology was emerging, it was being used in the making of
computer. With each new generation, the circuitry has gotten
smaller and more advanced than the previous generation before
it. As a result of the miniaturization, speed, power, and computer memory has proportionally increased. New discoveries are
constantly being developed that affect the way we live, work and
play.
A. First Generation (1945-1954)
First generation of computer started with using vacuum
tubes as the basic components for memory and circuitry for
CPU(Central Processing Unit)and were often enormous, taking
up entire rooms. These tubes like electric bulbs produced a lot
of heat and were prone to frequent fusing of the installations,
therefore, were very expensive and could be afforded only by
very large organisations.
In this generation mainly batch processing operating system
were used. 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.
Index Terms—Vacuum tubes, transistors, IC, VLSI, ULSI.
I. I NTRODUCTION
The first use word "computer" was recorded in 1613, referring to a person who carried out calculations, or computations,
and the word continued to be used in that sense until the
middle of the 20th century. From the end of the 19th century
onwards, though, the word began to take on its more familiar
meaning, describing a machine that carries out computations.
The history of the computer goes back several decades however there are totally five computer generations known till date.
Generation in computer is a step in technology. It provides a
framework for the growth of the computer industry. Initially,
the generation term was used to distinguish between varying
hardware technologies. But nowadays, generation includes
both hardware and software, which together make up an entire
computer system.
Each generation of computers is characterized by major
technological development that fundamentally changed the
way computers operate, resulting in increasingly smaller,
cheaper, more powerful and more efficient and reliable computing devices. Therefore, computers can be divided into five
generations depending upon the technologies used. These are:
• First Generation (1945 - 1954)
• Second Generation (1955 - 1964)
• Third Generation (1965 - 1974)
• Fourth Generation (1975 - 1990)
• Fifth Generation (1991 - present)
We’ve used approximate dates against each generations
which are normally accepted.
Figure 1.
UNIVAC - First Generation
The main features of First Generation are:
• Vacuum tube technology
• Unreliable
• Supported Machine language only
• Very costly
• Generate lot of heat
• Slow Input/Output device
• Huge size
• Need of A.C.
• Non portable
• Consumed lot of electricity
Some computer of this generation were:
• ENIAC
• EDVAC
• UNIVAC
• IBM-701
• IBM-650

2. B. Second Generation (1955-1964)
C. Third Generation (1965-1974)
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. Highlevel 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. There were Batch processing and
Multiprogramming Operating system used.The first computers
of this generation were developed for the atomic energy
industry.
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. In this generation Remote processing,
Time-sharing, Real-time, Multi-programming Operating System were used.High level language (FORTRAN-II TO IV,
COBOL, PASCAL PL/1, BASIC, ALGOL-68 etc.) were used
during this generation.
Figure 3.
Figure 2.
IBM 1620 - Second Generation
The main features of Second Generation are:
• Use of transistors
• Reliable as compared to First generation computers
• Smaller size as compared to First generation computers
• Generate less heat as compared to First generation computers
• Consumed less electricity as compared to First generation
computers
• Faster than first generation computers
• Still very costly
• A.C. needed
• Support machine and assmebly languages
Some computer of this generation were:
• IBM 1620
• IBM 7094
• CDC 1604
• CDC 3600
• UNIVAC 1108
IBM 370/168 - Third Generation
The main features of Third Generation are:
• IC used
• More reliable
• Smaller size
• Generate less heat
• Faster
• Lesser maintenance
• Still costly
• A.C needed
• Consumed lesser electricity
• Support high level language
Some computer of this generation were:
• IBM-360 series
• Honeywell-6000 series
• PDP(Personal Data Processor)
• IBM-370/168
• TDC-316
D. Fourth Generation (1975-1990)
The fourth generation of computers is marked by the use
of Very Large Scale Integrated (VLSI) circuits.VLSI circuits
having about 5000 transistors and other circuit elements and
their associated circuits on a single chip made it possible to
have microcomputers of fourth generation. Fourth Generation
computers became more powerful, compact, reliable, and

3. affordable. As a result, it gave rise to personal computer
(PC) revolution. In this generation Time sharing, Real time,
Networks, Distributed Operating System were used.All the
Higher level languages like C and C++, DBASE etc. were
used in this generation.
The Intel 4004 chip, developed in 1971, located all the
components of the computerfrom the central processing unit
and memory to input/output controlson 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. Fourth generation computers also saw
the development of GUIs, the mouse and handheld devices.
•
•
•
•
Neural networks
Game Playing
Development of expert systems to make decisions in real
life situations
Natural language understanding and generation
All the Higher level languages like C and C++, Java, .Net
etc. are used in this generation.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.
Figure 5.
Figure 4.
CRAY-1 - Fourth Generation
The main features of Fifth Generation are:
•
The main features of Fourth Generation are:
• VLSI technology used
• Very cheap
• Portable and reliable
• Use of PC’s
• Very small size
• Pipeline processing
• No A.C. needed
• Concept of internet was introduced
• Great developments in the fields of networks
• Computers became easily available
•
•
•
•
•
•
E. Fifth Generation (1991-present)
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. AI is an
emerging branch in computer science, which interprets means
and method of making computers think like human beings. AI
includes:
• Robotics
ULSI technology
Development of true artificial intelligence
Development of Natural language processing
Advancement in Parallel Processing
Advancement in Superconductor technology
More user friendly interfaces with multimedia features
Availability of very powerful and compact computers at
cheaper rates
Some computer of this generation were:
•
•
•
Some computer of this generation were:
• DEC 10
• STAR 1000
• PDP 11
• CRAY-1(Super Computer)
• CRAY-X-MP(Super Computer)
Laptop - Fifth Generation
•
•
Desktop
Laptop
NoteBook
UltraBook
ChromeBook
II. C ONCLUSION
Researching, studying and writing on History of the Computer has indeed been a fulfilling, but challenging task and
has brought about greater appreciation of several work done
by scientists of old, great developmental research carried out
by more recent scientists and of course the impact all such
innovations have made on the development of the human race.
It has generated greater awareness of the need to study history
of the computer as a means of knowing how to develop or
improve on existing computer technology. The saying that
there is nothing absolutely new under the sun is indeed real
because the same world resources but fresh ideas have been
used over the years to improve on existing technologies.

4. R EFERENCES
[1] Kai Hwang and Faye A. Briggs, Computer Architecture and Parallel
Processing, McGraw-Hill Book Company, 1984.
[2] Kai Hwang and Naresh Jotwani, Advanced Computer Architecture, 2nd
ed. McGraw-Hill Book Company, 2011.
[3] Carl Hamacher, Zvonko Vranesic and Safwat Zaky, Computer Organization, 5th ed. McGraw-Hill Book Company, 2002.