The document summarizes the evolution of computers from early counting devices like the abacus to the five generations of modern computers. It describes the key technological developments that defined each generation, including the transition from vacuum tubes to transistors to integrated circuits and microprocessors. It also categorizes types of computers based on their configuration and capabilities as super computers, mainframe computers, mini computers, or micro computers.

1. W. W. M. S. Karunasena
TG/2017/233
Computer Architecture - ICT1252
Evolution of Computers
- Assignment 01 -

2. Evolution of Computers
• • •
1
Contents
The Early Years ...................................................................................................................................... 2
➢ Abacus..................................................................................................................... 2
➢ Napier’s Bone .......................................................................................................... 2
Generations of Computers ............................................................................................................. 3
➢ First Generation (1942-1954) - Vacuum Tube ....................................................... 3
✓ The main features of First Generation................................................................................ 3
✓ Some computers of first generation were: ....................................................................... 4
➢ Second Generation Computers (1954 -1964) - Transistor.................................... 4
✓ The main features of Second Generation ........................................................................ 4
✓ Some computers of second generation were: ............................................................... 4
➢ Third Generation Computers (1964 -1972) - Integrated Circuit........................... 5
✓ The main features of Third Generation.............................................................................. 5
✓ Some computers of third generation were: ..................................................................... 5
➢ Fourth Generation (1972- Present) - VLSI Microprocessor ................................... 5
✓ The main features of Fourth Generation........................................................................... 6
✓ Some computers of fourth generation were: .................................................................. 6
➢ Fifth Generation (Present and Beyond) - ULSI Microprocessor............................ 6
✓ The main features of Fifth Generation............................................................................... 7
✓ Some computers of fifth generation were: ...................................................................... 7
Types of Computers - Based on Configuration.................................................................... 7
➢ Super Computers .................................................................................................... 8
✓ Use of Super Computers:...................................................................................................... 8
✓ Example:.................................................................................................................................. 8
➢ Mainframe Computers............................................................................................ 8
✓ Use of Mainframe Computers:............................................................................................ 8
✓ Example:.................................................................................................................................. 9
➢ Mini Computers ....................................................................................................... 9
✓ Use of Mini Computers:......................................................................................................... 9
✓ Example:.................................................................................................................................. 9
➢ Micro Computers .................................................................................................... 9
✓ Use of Micro Computers:...................................................................................................... 9
✓ Example:.................................................................................................................................. 9

3. Evolution of Computers
• • •
2
Since man is born with intelligence, he thought of ways that would make things easy
for him. One of the problems encountered by man was counting the things he had. Because of
this, he invented something that could help him count fast and easy.
The Early Years
In the early years, before the computer was invented, there were several inventions of
counting machine
• 200BC - Chinese Abacus
• 500BC - Egyptian Abacus
• 1620 - Napier’s Bone (John Napier)
• 1653 - Pascaline (Blaise Pascal)
• 1673 - Leibniz’s (Gottfried Wilhelm Von Leibniz)
• 1801 - Weaving loom (Joseph Marie Jacquard)
• 1823 - Mechanical Calculator Machine (Charles Babbage)
Abacus
 Used in Asia for a Long time (2000-3000 BCE)
 Also known as “SOROBAN” perform addition
and subtraction
 Wooden rack holding two horizontal wires with
beads strung on them
 Rules memorized by the user
 Regular arithmetic problems can be done
Napier’s Bone
 Set of eleven animal bones later it was replaced
by rod
 Number marked on them, they placed side by
side
 Products and quotients of large numbers could
be obtained

4. Evolution of Computers
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3
It is described in two parts.
 Generations of Computers
 Types of Computer - based on Configuration
Generations of Computers
The history of computer development is often referred to in reference to the different
generations of computer devices. Each generation of computer is characterized by a major
technological development that fundamentally changed the way computers operate, resulting
in increasingly smaller, cheaper, and more powerful and more efficient and reliable devices.
First Generation (1942-1954) - Vacuum Tube
First generation of computer started with using 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 organizations. In this generation
mainly, batch processing operating system were used. In this generation Punched cards,
Paper tape, Magnetic tape Input & Output device were used. There were Machine code and
electric wired board languages used.
The main features of First Generation
 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

5. Evolution of Computers
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4
Some computers of first generation were:
 ENIAC  EDVAC  UNIVAC
 IBM-701  IBM-650
Second Generation Computers (1954 -1964) - Transistor
This generation using the transistor 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 language like FORTRAN, COBOL were used. There were Batch
processing and Multiprogramming Operating system used.
The main features of Second Generation
 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 assembly languages
Some computers of second generation were:
 IBM 1620  IBM 7094  CDC 1604
 CDC 3600  UNIVAC 1108

6. Evolution of Computers
• • •
5
Third Generation Computers (1964 -1972) - Integrated
Circuit
The third generation of computer is marked by the use of Integrated Circuits (IC's) in
place of transistors. A single I.C has many transistors, resistors and capacitors along with the
associated circuitry. The I.C was invented by Jack Kilby. This development made computers
smaller in size, reliable and efficient. 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.
The main features of Third Generation
 More reliable
 Smaller size
 Generate less heat
 Faster
 Lesser maintenance
 Still costly
 A.C needed
 Consumed lesser electricity
 Support high level language
Some computers of third generation were:
 IBM-360 series  Honeywell-6000 series  TDC-316
 IBM-370/168  PDP (Personal Data Processor)
Fourth Generation (1972- Present) - VLSI Microprocessor
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 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.

7. Evolution of Computers
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6
The main features of Fourth Generation
 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 fourth generation were:
 DEC 10  STAR 1000  PDP 11
 CRAY-1(Super Computer)  CRAY-X-MP (Super Computer)
Fifth Generation (Present and Beyond) - ULSI
Microprocessor
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 Higher-
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.

8. Evolution of Computers
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7
The main features of Fifth Generation
 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 computers of fifth generation were:
 Desktop  Laptop  Notebook  Ultrabook
Types of Computers - Based on Configuration
On the basis of configuration that is architecture, processing, power, size of main
memory and other capabilities, computer can be divided in the following classes.
 Super Computers
 Mainframe Computers
 Mini Computers
 Micro Computers
Super Computer
Mainframe Computer
Mini Computer
Micro Computer
 Power  Cost
 Size  Speed

9. Evolution of Computers
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Super Computers
The most powerful computers in terms of performance and data processing are the
Supercomputers. These are specialized and task specific computers used by large
organizations. The supercomputers are very expensive and very large in size. It can be
accommodated in large air-conditioned rooms; some super computers can span an entire
building.
Use of Super Computer:
Super computers are used for research and exploration purposes, like NASA uses
supercomputers for launching space shuttles, controlling them and for space exploration
purpose. solving complex application such as Global Weather Forecasting. Creating graphic
images, engineering design and testing, space exploration and other problems where it is
necessary to process huge quantities of data quickly.
Example:
 IBM’s Sequoia, in United States  Fujitsu’s K Computer in Japan
 IBM’s Mira in United States  IBM’s SuperMUC in Germany
 NUDT Tianhe-1A in China
Mainframe Computers
Although Mainframes are not as powerful as supercomputers, but certainly they are
quite expensive nonetheless, and many large firms & government organizations uses
Mainframes to run their business operations. The Mainframe computers can be accommodated
in large air-conditioned rooms because of its size. Super-computers are the fastest computers
with large data storage capacity, Mainframes can also process & store large amount of data.
Use of Mainframe Computers:
Mainframe Computer are useful for dealing with large over changing collection of data
that are accessed by many users simultaneously such as banks, airlines, railways. Educational
institutions & insurance companies use mainframe computers to store data about their
customers, students & insurance policy holders.

10. Evolution of Computers
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Example:
 Fujitsu’s ICL VME  Hitachi’s Z800
Mini Computers
Minicomputers are used by small businesses & firms. Minicomputers are also called as
“Midrange Computers”. These are small machines and can be accommodated on a disk with
not as processing and data storage capabilities as super-computers & Mainframes. These
computers are not designed for a single user. Individual departments of a large company or
organizations use Mini-computers for specific purposes.
Use of Mini Computers:
Mini Computer are useful for tele communications. A production department can use
Mini-computers for monitoring certain production process.
Example:
 K-202  Texas Instrument TI-990
 SDS-92  IBM Midrange computers
Micro Computers
The micro-computers are widely used & the fastest growing computers. These
computers are the cheapest among the other three types of computers. Well known
manufacturers of Micro-computer are Dell, Apple, Samsung, Sony & Toshiba.
Use of Micro Computers:
The Micro-computers are specially designed for general usage like entertainment,
education and work purposes.
Example:
 Desktop computers  Gaming consoles  Smartphones
 Sound & Navigation system of a car  Netbooks  PDA’s
 Notebooks  Tablet PC’s  Laptop PC’s
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