1.2 Evolution of Computers - Programming in C

 

     Programming in C    

📖 Reference

The content for this subject is prepared by referring to the standard textbook “Computer Fundamentals and Programming in C” by Pradip Dey and Manas Ghosh, Second Edition, Oxford University Press (2018). The explanations are simplified and exam-focused while strictly aligning with the syllabus and concepts presented in the reference book.

1.2 Evolution of Computers – A Brief History

Introduction: 

The evolution of computers is a gradual process that spans several centuries. It can be broadly divided into mechanical era, electrical era, and electronic era, followed by rapid developments in microprocessors, programming languages, and operating systems.

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Computing in the Mechanical Era

The concept of calculating machines existed long before the invention of electrical and electronic devices.

• The first mechanical calculating device was the Abacus, invented around 500 BC in Babylon. It was used for basic arithmetic calculations and remained in use for many centuries without major improvements.

• In 1642, Blaise Pascal designed a mechanical calculator using gears and wheels, known as Pascal’s Calculator. It could perform addition and subtraction.

• In the early 1800s, practical geared mechanical calculators were developed, but these machines could only compute fixed calculations and could not be programmed.

A major breakthrough occurred in 1823 when Charles Babbage, with assistance from Augusta Ada Byron (Ada Lovelace), proposed the Analytical Engine for the Royal Navy of Great Britain.

• Input was given through punched cards.

• It could store 1,000 numbers of 20 digits each.

• It supported a modifiable program, making it the first concept of a programmable computer.

However, due to lack of precision in mechanical parts, the machine with over 50,000 components could not operate reliably.

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Computing in the Electrical Era

With the availability of electric motors in the 1800s, electrically driven machines replaced purely mechanical devices.

• In 1889, Herman Hollerith developed an electrically powered tabulating machine to process data stored on punched cards.

• He later formed the Tabulating Machine Company (1896), which eventually became IBM (International Business Machines).

These developments marked the transition toward large-scale data processing systems.

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Computing in the Electronic Era

The electronic era marked the beginning of modern computers.

• In 1941, Konrad Zuse developed the Z3, the first electronic calculating computer, used during World War II.

• In 1943, Alan Turing developed the Colossus, the first electronic computer, though it was not programmable.

• In 1946, J.W. Mauchly and J.P. Eckert developed ENIAC (Electronic Numerical Integrator and Calculator):

  • Used 17,000 vacuum tubes

  • Weighed 30 tons

  • Performed 100,000 operations per second

The IAS computer, developed by John von Neumann (1952), introduced the stored-program concept, which became the foundation for future computers.

During the 1950s, vacuum tube–based systems such as UNIVAC I, UNIVAC II, IBM Mark I, and IBM 701 were introduced.

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Transistor and Integrated Circuit Era

• In 1948, the transistor was invented at Bell Labs, replacing bulky vacuum tubes.

• By 1958, computers using transistors were developed by IBM, ICL, and DEC, which were:

  • Smaller in size

  • Faster

  • More reliable

  • Consumed less power

In 1958, Jack Kilby invented the Integrated Circuit (IC) at Texas Instruments.

• This led to SSI and MSI based computers such as IBM 360/370, PDP-8/1, and HP 9810 in the 1960s.

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Microprocessor and Personal Computer Era

• In 1971, Intel introduced the 4004, the first single-chip microprocessor.

• Subsequent developments included:

  • 8008 (1972)

  • 8080 and MC 6800 (1973)

  • 8085 (1974) – widely used general-purpose processor

• In 1981, IBM PC using 8088 microprocessor revolutionized personal computing.

• Further advancements:

  • 80286 (1983) – 16-bit

  • 80386 (1986) – 32-bit

  • 80486 (1989)

  • Pentium (1993) – affordable high-performance PCs

This era also saw the rise of laptops, palmtops, and portable computers, along with networking.

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Evolution of Programming Languages and Operating Systems

• Assembly language (1950s) for UNIVAC

• FORTRAN developed by IBM in 1957

• Later languages included ALGOL, COBOL, BASIC, PASCAL, C, C++, ADA, and JAVA

Operating systems further enhanced computer capabilities:

• UNIX for large and mini computers

• MS-DOS and Windows for personal computers

• Linux gained popularity due to open-source nature

Conclusion

The evolution of computers has progressed from simple mechanical devices to highly advanced electronic systems. Continuous improvements in hardware technology, programming languages, and operating systems have drastically enhanced performance, reliability, and usability of computers.

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