Chapter 2
Computer Generations
COM1013 – INFORMATION TECHNOLOGIES
Lecture Objectives
Understand the five generations of computers
◦ Identify key technologies in each generation
◦ Compare advantages and limitations
◦ Analyze societal impact of each generation
Machine Language
Machine language is the lowest-level programming
language that a computer understands directly. It consists
entirely of binary digits (0s and 1s), which represent
electrical signals (ON and OFF states) inside the computer’s
processor.
Key Features:
◦ Written in binary code (e.g., 10101010).
◦ Executed directly by the CPU without translation.
◦ Extremely fast because no compiler or interpreter is needed.
◦ Machine-dependent (different processors use different
machine codes).
What Are Computer Generations?
Computer generations refer to stages in the evolution of
computers.
◦ Each generation is defined by major technological
developments.
◦ They are classified based on hardware technology.
◦ Other factors include size, speed, cost, reliability, and
programming languages used.
◦ Understanding generations helps us see how computers
evolved into modern systems.
First Generation (1940–1956) –
Vacuum Tubes
Main Technology: Vacuum Tubes
◦ Computers were extremely large (room-sized machines).
◦ Consumed huge amounts of electricity and generated
excessive heat.
◦ Used Machine Language (binary 0s and 1s).
◦ Very expensive and unreliable (frequent breakdowns).
◦ Examples: ENIAC, UNIVAC I.
How Vacuum Tubes Worked
Vacuum tubes controlled the flow of electricity.
◦ They acted as switches to turn signals on and off.
◦ Thousands of tubes were required to perform
calculations.
◦ Major Problem: Tubes burned out quickly and required
constant maintenance.
Vacuum Tubes
First Generation Computer
Second Generation (1956–
1963) – Transistors
Main Technology: Transistors replaced vacuum tubes.
◦ Much smaller, faster, and more reliable.
◦ Consumed less electricity and produced less heat.
◦ Assembly language introduced.
◦ Magnetic core memory used for primary memory
storage.
◦ Example: IBM 1401.
Impact of Transistors
Reduced computer size significantly.
◦ Transistors are semiconductor devices that act as
electronic switches
◦ Increased processing speed.
◦ Reduced cost of production.
◦ Computers began to be used in businesses and
government offices.
Transistors
Second Generation Computer
Third Generation (1964–1971)
– Integrated Circuits
Main Technology: Integrated Circuits (ICs).
◦ Multiple transistors placed on a single silicon chip.
◦ Much smaller and more powerful than second
generation.
◦ Operating Systems were introduced.
◦ High-level programming languages such as COBOL and
FORTRAN became popular.
◦ Example: IBM System/360.
Major Advancements in Third
Generation
Introduction of keyboards and monitors.
◦ Multiprogramming (running multiple programs at once).
◦ Improved storage devices.
◦ Greater reliability and efficiency.
Integrated Circuits (IC)
Third Generation Computer
Fourth Generation (1971–
Present) – Microprocessors
Main Technology: Microprocessor (CPU on a single chip).
◦ Thousands to billions of transistors integrated into one
chip.
◦ Led to development of Personal Computers (PCs).
◦ Very high processing speeds.
◦ Affordable and widely accessible.
◦ Examples: Apple II, IBM PC.
Impact of Microprocessors
Computers became available for home use.
◦ Development of laptops and smartphones.
◦ Graphical User Interface (GUI) introduced.
◦ Growth of the Internet and global communication.
Microprocessors
Fourth Generation Computer
Fifth Generation (Present &
Beyond) – Artificial Intelligence
Main Focus: Artificial Intelligence (AI).
◦ Systems capable of learning and decision-making.
◦ Uses Machine Learning and Deep Learning techniques.
◦ Natural Language Processing (voice recognition).
◦ Parallel processing and advanced computing technologies.
◦ Goal: Develop intelligent systems that mimic human thinking.
Examples of Fifth Generation
Applications
Virtual Assistants (Siri, Alexa).
◦ Self-driving cars.
◦ Robotics and automation systems.
◦ AI-based medical diagnosis systems.
◦ Smart recommendation systems.
Fifth Generation Computer
Comparison of Computer
Generations
◦ 1st: Vacuum Tubes – Very Large, Slow, Machine Language.
◦ 2nd: Transistors – Smaller, Faster, Assembly Language.
◦ 3rd: Integrated Circuits – Smaller, OS Introduced, HighLevel Languages.
◦ 4th: Microprocessors – Personal Computers, GUI, Internet
Growth.
◦ 5th: Artificial Intelligence – Intelligent and Self-Learning
Systems.
Summary
Computers evolved from large vacuum tube machines to
intelligent AI systems.
◦ Each generation introduced major technological
improvements.
◦ Size decreased while speed and efficiency increased.
◦ Modern computers are the result of decades of
innovation and development.