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Generations of computers.

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Objective:

On completion of this period, you would be On completion of this period, you would be able to know:able to know:

The generations of computers.The generations of computers.

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Generations of computers

The first generation computers

The second generation computers

The third generation computers

The fourth generation computers

The fifth generation computers

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The First Generation Computers.

The digital computer using electronic device (vacuum tubes) is known as the first generation computer.

The first generation computer used vacuum tube as a CPU component.

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The first generation computers (contd):

Vacuum Tube is the main technology Acoustic delay lines were used for memory These are costly but slower devices Larger in size Produced more heat Maintenance was needed Highly unreliable.

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The first generation computers (contd):

They used fixed-point arithmetic

Examples : IBM 700 series – IBM 701, IBM 704, IBM 709, EDVAC and UNIVAC.

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The second generation computers

The second generation computers used transistors as CPU components

Ferrite cores for main memory and magnetic disks and tapes for secondary memory.

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The third generation computers

The third generation computers used ICs (SSI and MSI) as CPU components.

These used magnetic core memory, but later on semiconductor memories.

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The third generation computers (contd)

Semiconductor memories were LSI chips.

Concept of Cache memory was introduced.

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The third generation computers (contd)

Micro programming, parallel processing, multi processing, multi user system and time sharing system etc were introduced.

Examples:IBM/370 series (1970),CDC 7600 (1969), CDC’s CYBER-175 and STAR-100,etc

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The fourth generation computers

Fourth generation computers use VLSI chips for CPU, memory and supporting chips.

They use microprocessor as CPU (32 bit or 64 bit).

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The fourth generation computers (contd)

They also contain many other essential components such as FPU (Floating Point Unit), MMU (Memory Management Unit), first level and second level cache memory etc.

Examples of latest microprocessors :Pentium II and Pentium III, Power PC ,DEC’s Alpha, SUN’s ULTRASPARC ,AMD’s K-6,K-7,etc

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The fifth generation computers (contd) :

The fifth generation computers are under development stage.

These computers will use ULSI (ultra large scale integration) chips.

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The fifth generation computers (contd) :

ULSI chips contain millions of components into a single IC.

The input and output information for these computers will be in the form of speech and graphic images

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The fifth generation computers (contd) :

The computer will understand natural languages like English , Japanese , etc.

The programmers will not have to learn programming languages.

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The fifth generation computers (contd) :

They will be able to speak commands or key information in their mother tongue

Vision system will also be incorporated.

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GENERATIONS OF COMPUTERSGenerations Components

usedAdvantages Disadvantages Examples

First (1946-1954)

Vacuum tubes Machine Language Costlier, more space, excess power

IBM700,ENIAC,EDVAC

Second(1955-1964)

Transistors Less expensive, less power,

Cheaper & small in size

Used Assembly Language

IBM7090, IBM7094 I,

IBM9094 II

Third(1965-1974)

Integrated circuits, Semi conductor memory

Smaller, Faster, Cheaper -

IBM/370 series, Cyber175

Fourth(1975-1984)

VLSI chips Faster, Less power consumption

Uses one or more microprocessors

CRAY Y_MPC,

WIPRO LANDMARK 860

Fifth(1985-present)

ULSI Very high performance, Easy access, Multiprocessing

- Windows 2000, Xp, Linux

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Summary

In this class, we have learnt about

Generations of computers

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Frequently Asked Questions

Explain different generations of computers?

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Quiz

1. The third generation computers used

a. vacuum tubes

b. transistors

c. ICs

d. LSI

Answer: c

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Quiz

2. The second generation computers used

a. vacuum tubes

b. transistors

c. ICs

d. LSI

Answer: b

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Quiz

3. The first generation computers used

a. vacuum tubes

b. transistors

c. ICs

d. LSI

Answer: a