The document discusses the six generations of computers from 1946 to the present. Each generation saw improvements in the technology used in computer circuits and components that made computers smaller, more powerful, reliable and affordable. The first generation used vacuum tubes, the second used transistors, the third used integrated circuits, the fourth used VLSI circuits, the fifth used ULSI, and the sixth now uses quantum computing techniques. Each new generation brought advantages like increased speed and memory capacity while reducing size, heat, and energy usage compared to the prior generation.

1. Topic: Generations of Computers
By: Dr. Mirza Waseem Hussain
Lecturer Computer Science
Dr. Mirza Waseem Hussain 1

2. Generation of computers refers to the specific improvements in
computer technology with time.
In 1946, electronic pathways called circuits were developed to perform
the counting thus replacing gears and other mechanical parts used in
earlier machines.
In each new generation, the circuits became smaller and more
advanced than the previous generation circuits.
The miniaturization helped in increase of speed, memory and power of
computers.
Dr. Mirza Waseem Hussain 2

3. 1. First Generation Computers(1946-1959)
Use of vacuum tubes as basic component of CPU and
memory.
Paper tape and Magnetic tape were used
as Input and output devices.
Machine language that uses 0s and 1s for coding of the
instructions.
These computers were mainly depended on batch
operating system and punch cards.
Some of the popular first generation computers are:
• ENIAC ( Electronic Numerical Integrator and Computer)
• EDVAC ( Electronic Discrete Variable Automatic Computer)
• UNIVACI( Universal Automatic Computer)
• IBM-701
• IBM-650
Fig.1: Vacuum Tube
Fig.2: First Generation computer (ENIAC)
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4. I. Advantages of First Generation of Computer:
a) These computers fast and could calculate data in millisecond.
II. Disadvantages of First Generation of Computer:
a) The computers were very large in size.
b) They consumed a large amount of energy.
c) They heated very soon due to thousands of vacuum tubes.
d) They were not very reliable.
e) Air conditioning was required.
f) Constant maintenance was required.
g) Used machine language only.
Dr. Mirza Waseem Hussain 4

5. 2. Second Generation Computers(1959-1965)
Use of transistor.
Transistors were highly reliable and easier to handle and maintain than the
vacuum tubes.
Magnetic cores were used as the primary memory and magnetic disc and
tapes were used as the secondary storage.
 Assembly language and programming languages like COBOL and FORTRAN.
 Batch processing and multiprogramming operating systems were used.
 Some of the popular second generation computers are;
• IBM 1620
• IBM 7094
• CDC 1604
• CDC 3600
• UNIVAC 110
Fig.3: Transistor
Fig.4: Second Generation ComputerDr. Mirza Waseem Hussain 5

6. I. Advantage:
a) Smaller in size compared to the first generation of computer.
b) The second generations computers were more reliable.
c) Used less energy and were not heated as much as the first one.
d) Better speed and could calculate data in microseconds.
e) Used assembly language as well.
II. Disadvantages of First Generation of Computer:
a) Cooling system was required.
b) Still very costly.
c) Only used for specific purposes.
d) Constant maintenance was required.
Dr. Mirza Waseem Hussain 6

7. 3. Third Generation of Computer (1965 - 1974)
Integrated circuits (ICs) instead of transistors.
Integrated circuits were developed by interconnecting
transistors, resistors and capacitors grown on a single chip of silicon.
Silicon transistors replaced germanium transistors.
The computers also became more reliable, efficient and smaller in size.
These generation computers used remote processing, time-sharing, multi
programming as operating system.
Use of high-level programming languages like
FORTRON-II TO IV, COBOL, PASCAL PL/1, ALGOL-68.
Fig.5: IC
Fig.6: Third Generation ComputerDr. Mirza Waseem Hussain 7

8. Some of the popular third generation computers are;
• IBM-360 series
• Honeywell-6000 series
• PDP(Personal Data Processor)
• IBM-370/168
• TDC-316
I. Advantage:
a) Smaller in size as compared to previous generations.
b) More reliable as compared to previous generations.
c) Used less energy as compared to previous generations.
d) Produced less heat as compared to the previous two generations of
computers.
e) Maintenance cost was low because hardware failure is rear.
f) Better speed and could calculate data in nanoseconds.
g) Good storage.
h) Could be used for high-level languages.
i) Used mouse and keyboard for input. Dr. Mirza Waseem Hussain
8

9. II. Disadvantages
a) Air conditioning was required.
b) Highly sophisticated technology required for the manufacturing of IC chips.
4. Fourth Generation Computers (1971-1980)
Use of very large scale integrated (VLSI) circuits; a chip
containing millions of transistors and other circuit elements.
Computers were now more compact, powerful, fast and affordable.
 Magnetic core memories were replaced by semiconductor memories.
Used real time, time sharing and distributed operating system.
Graphic User Interface (GUI) technology was exploited to
offer more comfort to users.
The programming languages like C, C++, DBASE,ADA were
also used in this generation.
Personal computer operating systems were developed during this period.
Fig.8: Fourth Generation Computer
Fig.7: VLSI
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10. Some of the popular fourth generation computers are;
• DEC 10
• STAR 1000
• PDP 11
• CRAY-1(Super Computer)
• CRAY-X-MP(Super Computer)
I. Advantage:
a) More powerful and reliable than previous generations.
b) Small in size.
c) Fan for heat discharging and thus to keep cold.
d) Fast processing power with less power consumption
e) No air conditioning required.
f) Less need of repair.
g) All types of High level languages can be used in this type of
computers.
h) Cheapest among all generations.Dr. Mirza Waseem Hussain 10

11. II. Disadvantages
a) The latest technology is required for manufacturing of Microprocessors.
5. Fifth Generation Computers(1980-beginning of twentieth century)
VLSI technology was replaced with
ULSI (Ultra Large Scale Integration).
Possible production of microprocessor chips with
ten million electronic components.
Parallel processing hardware and AI
(Artificial Intelligence) software.
The programming languages used in this generation
were C, C++, Java, .Net,Lisp etc.
Some of the popular fifth generation computers are;
• Desktop
• Laptop
• NoteBook
• UltraBook
• ChromeBook Fig.10: Fifth Generation Computer
Fig.9: ULSI
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12. I. Advantage:
a) These computers are much faster than other generation computers.
b) It is easier to repair these computers.
c) These computers are much smaller in size than other generation
computers.
d) They are portable and easy to handle.
e) Development of true artificial intelligence.
f) Advancement in Parallel Processing.
g) Advancement in Superconductor technology.
II. Disadvantages:
a) They tend to be sophisticated and complex tools.
b) Give more power to companies to watch what you are doing and
even allow them to infect your computer.Dr. Mirza Waseem Hussain 12

13. 6. Sixth Generation of Computers(Starting of 20th century till date)
The sixth generation also introduced voice recognition.
Improved technology allows the computer to take dictation and recognize
words.
The use of nanotechnology is a characteristic of sixth generation
computers.
Use of qubits or quantum bits process calculations.
This new advancement will allow students and the disabled to speak
commands into the computer without touching the physical device.
I. Advantage:
a) These computers are much faster than
other generation computers.
b) These computers are much smaller in size than
other generation computers
c) Use of Quantum mechanics.Dr. Mirza Waseem Hussain 13

14. II. Disadvantages:
a) Requires very sophisticated and complex technology to manufacture and
repair.
Dr. Mirza Waseem Hussain 14

15. Source:
• http://vishnumustapure.blogspot.com/2017/12/generation-of-
computer.html
• https://www.tutorialspoint.com/computer_fundamentals/computer_gener
ations.htm
• http://www.generalnote.com/Basic-computer/Images/second-generaton-
computer.jpg
• https://en.wikipedia.org/wiki/ENIAC
• https://www.computertechmate.com/2018/09/third-generation-of-
computer.html
• https://www.javatpoint.com/history-of-computer
• http://historyofcomputerandetc.blogspot.com/2016/09/fifth-generation-
present-and-beyond.html
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16. Dr. Mirza Waseem Hussain 16