Computer Generations
Generation in computer terminology is a change in technology a computer is/was being used.
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.
There are totally five computer generations known till date. Each generation has been discussed
in detail along with their time period and characteristics. Here approximate dates against each
generations have been mentioned which are normally accepted.
Following are the main five generations of computers
S.N Generation & Description
.
1 First Generation
The period of first generation: 1946-1959. Vacuum tube based.
2 Second Generation
The period of second generation: 1959-1965. Transistor based.
3 Third Generation
The period of third generation: 1965-1971. Integrated Circuit based.
4 Fourth Generation
The period of fourth generation: 1971-1980. VLSI microprocessor based.
5 Fifth Generation
The period of fifth generation: 1980-onwards. ULSI microprocessor based
Computer - First Generation
The period of first generation was 1946-1959. The computers
of first generation used vacuum tubes as the basic
components for memory and circuitry for CPU (Central
Processing Unit). 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.
Punched cards, paper tape, and magnetic tape were used as
input and output devices. The computers in this generation
used machine code as programming language.
The main features of first generation are:
Vacuum tube technology
Unreliable
Supported machine language only
Very costly
Generated lot of heat
Slow input and output devices
Huge size
Need of A.C.
Non-portable
Consumed lot of electricity
Some computers of this generation were:
ENIAC
EDVAC
UNIVAC
IBM-701
IBM-650
Computer - Second Generation
The period of second generation was 1959-1965. In this generation transistors were used that
were cheaper, consumed less power, more compact in size, more reliable and faster than the first
generation machines made of vacuum tubes. In this generation, magnetic cores were used as
primary memory and magnetic tape and magnetic disks as secondary storage devices. In this
generation assembly language and high-level programming languages like FORTRAN, COBOL
were used. The computers used batch processing and multiprogramming operating system.
The main features of second generation are:
Use of transistors
Reliable in comparison to first generation computers
Smaller size as compared to first generation computers
Generated 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
Supported machine and assembly
languages
Some computers of this generation were:
IBM 1620
IBM 7094
CDC 1604
CDC 3600
UNIVAC 1108
Computer - Third Generation
The period of third generation was 1965-1971. The computers of third generation used integrated
circuits (IC's) in place of transistors. A single IC has many transistors, resistors and capacitors
along with the associated circuitry. The IC was invented by Jack Kilby. This development made
computers smaller in size, reliable and efficient. In this generation remote processing, time-
sharing, multi-programming operating system were used. High-level languages (FORTRAN-II
TO IV, COBOL, PASCAL PL/1, BASIC, ALGOL-68 etc.) were used during this generation.
The main features of third generation are:
IC used
More reliable in comparison to previous two generations
Smaller size
Generated less heat
Faster
Lesser maintenance
Still costly
A.C needed
Consumed lesser electricity
Supported high-level language
Some computers of this generation were:
IBM-360 series
Honeywell-6000 series
PDP(Personal Data Processor)
IBM-370/168
TDC-316
Computer - Fourth Generation
The period of fourth generation was 1971-1980. The computers of fourth generation used 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 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 high-level languages like C, C++, DBASE etc., were used in this generation.
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
Some computers of this generation were:
DEC 10
STAR 1000
PDP 11
CRAY-1(Super Computer)
CRAY-X-MP(Super Computer)
Computer - Fifth Generation
The period of fifth generation is 1980-till date. In the fifth generation, the VLSI technology
became ULSI (Ultra Large Scale Integration) technology, resulting in the production of
microprocessor chips having ten million electronic components. This generation is based on
parallel processing hardware and AI (Artificial Intelligence) software. AI is an emerging branch
in computer science, which interprets means and method of making computers think like human
beings. All the high-level languages like C and C++,
Java, .Net etc., are used in this generation.
AI includes:
Robotics
Neural Networks
Game Playing
Development of expert systems to make decisions
in real life situations.
Natural language understanding and generation.
The main features of fifth generation are:
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 types of this generation are:
Desktop
Laptop
NoteBook
UltraBook
ChromeBook
Computer - Types
Computers can be broadly classified by their speed and computing power.
Sr.No. Type Specifications
1 PC (Personal It is a single user computer system having moderately powerful
Computer) microprocessor
2 WorkStation It is also a single user computer system which is similar to
personal computer but have more powerful microprocessor.
3 Mini Computer It is a multi-user computer system which is capable of supporting
hundreds of users simultaneously.
4 Main Frame It is a multi-user computer system which is capable of supporting
hundreds of users simultaneously. Software technology is
different from minicomputer.
5 Supercomputer It is an extremely fast computer which can execute hundreds of
millions of instructions per second.
PC (Personal Computer)
A PC can be defined as a small, relatively inexpensive computer designed for an individual user.
PCs are based on the microprocessor technology that enables manufacturers to put an entire CPU
on one chip. Businesses use personal computers for word processing, accounting, desktop
publishing, and for running spreadsheet and database management applications. At home, the
most popular use for personal computers is playing games and
surfing Internet.
Although personal computers are designed as single-user
systems, these systems are normally linked together to form a
network. In terms of power, now-a-days High-end models of
the Macintosh and PC offer the same computing power and
graphics capability as low-end workstations by Sun
Microsystems, Hewlett-Packard, and Dell.
Workstation
Workstation is a computer used for engineering applications (CAD/CAM), desktop publishing,
software development, and other such types of applications which require a moderate amount of
computing power and relatively high quality
graphics capabilities.
Workstations generally come with a large, high-
resolution graphics screen, large amount of RAM,
inbuilt network support, and a graphical user
interface. Most workstations also have a mass
storage device such as a disk drive, but a special
type of workstation, called a diskless workstation,
comes without a disk drive.
Common operating systems for workstations are
UNIX and Windows NT. Like PC, Workstations
are also single-user computers like PC but are
typically linked together to form a local-area network, although they can also be used as stand-
alone systems.
Minicomputer
It is a midsize multi-processing system capable of supporting up to 250
users simultaneously.
Mainframe
Mainframe is very large in size and is an expensive computer
capable of supporting hundreds or even thousands of users
simultaneously. Mainframe executes many programs
concurrently and supports many simultaneous execution of
programs
Supercomputer
Supercomputers are one of the fastest computers currently available.
Supercomputers are very expensive and are employed for
specialized applications that require immense amount of
mathematical calculations (number crunching). For example,
weather forecasting, scientific simulations, (animated) graphics,
fluid dynamic calculations, nuclear energy research, electronic design, and analysis of geological
data (e.g. in petrochemical prospecting).
