This document discusses the history and generations of computers. It describes the early abacus and mechanical calculating devices. Important early electronic computers included Charles Babbage's Analytical Engine, the Mark I, the Atanasoff-Berry Computer, ENIAC, EDVAC, and EDSAC. The five generations of computers are then defined based on the technology used - first generation used vacuum tubes, second used transistors, and third used integrated circuits. Key aspects and characteristics of the first two generations are provided.

1. COMPUTERCOMPUTER
GENERATIONSGENERATIONS

2. HISTORY OF COMPUTERSHISTORY OF COMPUTERS
When the human race started doingWhen the human race started doing
some trade , it felt a need for asome trade , it felt a need for a
calculating device . Early mancalculating device . Early man
developed a device known asdeveloped a device known as
ABACUS. This was used mainlyABACUS. This was used mainly
in China and Japan. Blaise Pascalin China and Japan. Blaise Pascal
developed first mechanical devicedeveloped first mechanical device
in 1642. In 1671 a Germanin 1642. In 1671 a German
mathematician developed a devicemathematician developed a device
which took out add, subtract,which took out add, subtract,
multiply, division and even squaremultiply, division and even square
root.root.

3. CHARLES BABBAGECHARLES BABBAGE
Charles Baggage is the Father ofCharles Baggage is the Father of
Modern Digital Computer. InModern Digital Computer. In
1833 he proposed a machine and1833 he proposed a machine and
named it analytical engine. Henamed it analytical engine. He
spent much of his time in buildingspent much of his time in building
this machine but never succeededthis machine but never succeeded
as the precision engineeringas the precision engineering
required to build this was notrequired to build this was not
available at that time. Theavailable at that time. The
principles established by him areprinciples established by him are
used in making of modern digitalused in making of modern digital
computers.computers.

4. MARK I COMPUTERSMARK I COMPUTERS
The Mark I Computer also calledThe Mark I Computer also called
as Automatic Sequenceas Automatic Sequence
Controlled calculator was theControlled calculator was the
first fully automatic calculatingfirst fully automatic calculating
machine. It was not an electronicmachine. It was not an electronic
computer. Rather it was ancomputer. Rather it was an
electromechanical computer. Theelectromechanical computer. The
size was huge and design complexsize was huge and design complex
but it was quite reliable. It hadbut it was quite reliable. It had
the capacity to perform five basicthe capacity to perform five basic
functions.functions.

5. ATANASTOFF COMPUTERATANASTOFF COMPUTER
This computer is named after itsThis computer is named after its
developer , the professor ofdeveloper , the professor of
Physics and Mathematics ,Physics and Mathematics ,
Doctor John VincentDoctor John Vincent
Atanastoff . It was the firstAtanastoff . It was the first
electronic computer. It waselectronic computer. It was
developed to solve certaindeveloped to solve certain
mathematical operations. Itmathematical operations. It
used 45 vacuum tubes forused 45 vacuum tubes for
internal logic and capacitorsinternal logic and capacitors
for storagefor storage

6. ENIACENIAC
The Electronic NumericalThe Electronic Numerical
Integrator And CalculatorIntegrator And Calculator
was the first machine . It waswas the first machine . It was
developed by J Presper Eckertdeveloped by J Presper Eckert
Jr. and John W Mauchly . ItJr. and John W Mauchly . It
used 19000 vacuum tubes . Itused 19000 vacuum tubes . It
covered 800 sq. feet. It couldcovered 800 sq. feet. It could
do 300 calculations per seconddo 300 calculations per second
but it couldn’t be storedbut it couldn’t be stored
internally , these were fedinternally , these were fed
through electrically wiredthrough electrically wired
plug boards.plug boards.

7. EDVACEDVAC
The Electronic Discrete VariableThe Electronic Discrete Variable
Automatic Computer was theAutomatic Computer was the
first effort to develop a storedfirst effort to develop a stored
instruction computer. A teaminstruction computer. A team
led by J. Presper Eckert Jr.led by J. Presper Eckert Jr.
and John W Mauchly made it.and John W Mauchly made it.
Its design concepts were thatIts design concepts were that
both data and instructions canboth data and instructions can
be stored in binary form. Thisbe stored in binary form. This
influenced the development ofinfluenced the development of
modern digital computers.modern digital computers.

8. EDSACEDSAC
Almost simultaneously with EDVACAlmost simultaneously with EDVAC
The britisher’s developed theThe britisher’s developed the
Electronic Delay StorageElectronic Delay Storage
Automatic Calculator. The teamAutomatic Calculator. The team
lead by professor Maurice Wilkeslead by professor Maurice Wilkes
developed it . In this , additiondeveloped it . In this , addition
operations were accomplished inoperations were accomplished in
1500 microseconds and1500 microseconds and
multiplication operations in 4000multiplication operations in 4000
microseconds . It held it’s firstmicroseconds . It held it’s first
program demonstration in Mayprogram demonstration in May
19491949

9. UNIVACUNIVAC
The Universal Automatic ComputerThe Universal Automatic Computer
was the first digital computerwas the first digital computer
which was not of one kind. Manywhich was not of one kind. Many
computers were produced, thecomputers were produced, the
first of which was installed infirst of which was installed in
Census Bureau of 1951 and wasCensus Bureau of 1951 and was
used continuously for 10 years.used continuously for 10 years.
The first business use of aThe first business use of a
computer , a UNIVAC I , was bycomputer , a UNIVAC I , was by
General Electric Corporation inGeneral Electric Corporation in
19541954

10. COMPUTERCOMPUTER
GENERATIONSGENERATIONS
The word generation in computer means a step in technology.The word generation in computer means a step in technology.
It provides a framework for the growth of the computerIt provides a framework for the growth of the computer
industry. The term is used to distinguish between theindustry. The term is used to distinguish between the
hardware and software components, which make the entirehardware and software components, which make the entire
computer systemcomputer system
The custom of referring to the computer era in terms ofThe custom of referring to the computer era in terms of
generations came into wide use only after 1964. there aregenerations came into wide use only after 1964. there are
total five generations known today.total five generations known today.

11. FIRST GENERATIONFIRST GENERATION
The early electronic computers usedThe early electronic computers used
vacuum tubes to control flow ofvacuum tubes to control flow of
electricity. Vacuum tubes are big inelectricity. Vacuum tubes are big in
size and produce a lot of heat.size and produce a lot of heat.
Because of this first generationBecause of this first generation
computers were too bulky in sizecomputers were too bulky in size
and produced a lot of heat.and produced a lot of heat.
Therefore, they needed airTherefore, they needed air
conditioning. The vacuum tubesconditioning. The vacuum tubes
used to burn out frequently . Soused to burn out frequently . So
these can not be used regularly andthese can not be used regularly and
had to be stoppedhad to be stopped

12. CHARACTERISTICSCHARACTERISTICS
1.1. They were fastest calculating device of their time.They were fastest calculating device of their time.
2.2. They were too bulky in size requiring large rooms forThey were too bulky in size requiring large rooms for
installationsinstallations
3.3. Thousands of vacuum tubes emitted heat and burn outThousands of vacuum tubes emitted heat and burn out
frequently. Rooms storing these had to be air conditioned.frequently. Rooms storing these had to be air conditioned.
4.4. As vacuum tubes used filaments they had a limited life.As vacuum tubes used filaments they had a limited life.
5.5. Due to such low time means failure, these computersDue to such low time means failure, these computers
required almost constant maintenance.required almost constant maintenance.
6.6. Since these types of computers were very difficult toSince these types of computers were very difficult to
program and use they had limited commercial use.program and use they had limited commercial use.

13. SECOND GENERATIONSECOND GENERATION
The computers of the secondThe computers of the second
generation were introducedgeneration were introduced
around 1959. These were made ofaround 1959. These were made of
transistors , a smaller and moretransistors , a smaller and more
reliable component invented inreliable component invented in
1947 . A transistor is very small1947 . A transistor is very small
to vacuum tubes and producesto vacuum tubes and produces
very little heat. The use ofvery little heat. The use of
transistors in computers made thetransistors in computers made the
second generation computerssecond generation computers
faster, smaller and reliablefaster, smaller and reliable

14. CHARACTERISTICSCHARACTERISTICS
1.1. They were more rugged and easier to handle than tubesThey were more rugged and easier to handle than tubes
since they were made of germanium semiconductor.since they were made of germanium semiconductor.
2.2. They were highly reliable as compared to tubes since theyThey were highly reliable as compared to tubes since they
had no part like filament making it burn out.had no part like filament making it burn out.
3.3. They could switch 10 times faster than tubes.They could switch 10 times faster than tubes.
4.4. They consume almost one tenth of power consumed byThey consume almost one tenth of power consumed by
tube.tube.
5.5. They were much smaller in size than a tube.They were much smaller in size than a tube.
6.6. They were less expensive to produce.They were less expensive to produce.
7.7. They dissipated much less heat than vacuum tubes.They dissipated much less heat than vacuum tubes.

15. THIRD GENERATIONTHIRD GENERATION
The introduction of the integratedThe introduction of the integrated
chips opened the door for thechips opened the door for the
development of third generationdevelopment of third generation
computers. A very large no. ofcomputers. A very large no. of
circuit elements could be integratedcircuit elements could be integrated
into a very small surface of silicon.into a very small surface of silicon.
These computers were based on IC .These computers were based on IC .
These were faster, smaller, andThese were faster, smaller, and
more reliable than secondmore reliable than second
generation. The System/360 wasgeneration. The System/360 was
the first third generation computerthe first third generation computer
introduced by IBMintroduced by IBM

16. CHARACTERISTICSCHARACTERISTICS
1.1. They were 10 times faster than second generationThey were 10 times faster than second generation
computers. They were able to reduce timecomputers. They were able to reduce time
2.2. They were much smaller in size requiring smaller space forThey were much smaller in size requiring smaller space for
installationsinstallations
3.3. Although they dissipated less heat the rooms had to be airAlthough they dissipated less heat the rooms had to be air
conditioned.conditioned.
4.4. They were more reliable and less prone to hardwareThey were more reliable and less prone to hardware
failures.failures.
5.5. They had faster and larger primary and secondary storageThey had faster and larger primary and secondary storage
devices.devices.

17. FOURTH GENERATIONFOURTH GENERATION
There were about 10 to 20There were about 10 to 20
components contained in IC. Withcomponents contained in IC. With
advancement of technology itadvancement of technology it
contained over 30000 componentscontained over 30000 components
and became to be known as Largeand became to be known as Large
Scale Integration. FourthScale Integration. Fourth
generation computers were based ongeneration computers were based on
LSI chips. Because of the veryLSI chips. Because of the very
small size of the IC’s used in fourthsmall size of the IC’s used in fourth
generation computers, that’s whygeneration computers, that’s why
these are small, powerful, cheapthese are small, powerful, cheap

18. CHARACTERISTICSCHARACTERISTICS
1.1. The pc’s were much smaller and cheaper than theThe pc’s were much smaller and cheaper than the
mainframe of third generations computers.mainframe of third generations computers.
2.2. No air conditioning was required for PC’sNo air conditioning was required for PC’s
3.3. They consumed less powerThey consumed less power
4.4. They were much more reliable and less prone to hardwareThey were much more reliable and less prone to hardware
faults hence the maintenance cost was negligible.faults hence the maintenance cost was negligible.
5.5. They were totally general purpose machines.They were totally general purpose machines.
6.6. GUI enabled users how to learn to use it.GUI enabled users how to learn to use it.
7.7. They had faster and larger primary memory and secondaryThey had faster and larger primary memory and secondary
storage devicesstorage devices

19. FIFTH GENERATIONFIFTH GENERATION
Scientists are working onScientists are working on
the development of thethe development of the
fifth generationfifth generation
computers that willcomputers that will
have intelligence ,have intelligence ,
ability to reason andability to reason and
learn , knowledge of thelearn , knowledge of the
real world , and whichreal world , and which
can understand and talkcan understand and talk
in natural language.in natural language.

20. A POWERPOINTA POWERPOINT
PRESENTATIONPRESENTATION
BYBY
AVASYU GUPTAAVASYU GUPTA
IX DIX D
ROLL NO. 8ROLL NO. 8