CSC-101 Introduction to Computing: Lecture 02 - History and Evolution of Computers

History of Computers

The journey of computing technology began with simple devices like the abacus, which dates back to approximately 3000 BC. It served as an early counting tool. Subsequent innovations laid the foundation for modern computing:

Charles Babbage (1833): Developed the first mechanical computer and is credited with designing the Analytical Engine, a precursor to the general-purpose computer.
Abacus (3000 BC)
Napier’s Bone (1617): A calculating tool using rods, facilitating multiplication and division.
Pascaline (1642): Introduced by Blaise Pascal, it was one of the first mechanical calculators.
Leibniz Wheel (1685): Developed by Gottfried Wilhelm Leibniz for various arithmetic operations.
Difference Engine (1822): Created by Babbage for automatic polynomial calculations.
Analytical Engine (1822): Also devised by Babbage, it was designed to perform any arithmetic operation.
Tabulating Machine (1858): Invented by Herman Hollerith to process data efficiently.
Differential Analyzer (1931): A mechanical analog computer designed for solving differential equations.
Mark I (1944): An early electromechanical computer, developed by Howard Aiken.

Generations of Computers

The evolution of computers can be categorized into different generations, characterized by advancements in technology:

Vacuum Tubes: The first generation used vacuum tubes for switching and amplification.
Transistors: Replaced vacuum tubes in the second generation, being smaller, more reliable, and energy-efficient.
Integrated Circuits (IC): The third generation introduced ICs, combining multiple components on a single chip, greatly increasing computing power and efficiency.
Very-Large-Scale Integration (VLSI): In the fourth generation, thousands of transistors were integrated onto a single chip.
Ultra-Large-Scale Integration (ULSI): Current technology integrates millions of components on a single chip.

Evolution of Notable Computers

The timeline of computer development has seen significant milestones:

1936: Konrad Zuse created the first motor-driven computer, the Z1, capable of addition and subtraction.
1940: ENIAC (Electronic Numerical Integrator and Calculator) was developed by John Mauchly during World War II to assist in ballistic calculations. It was a massive machine weighing 30 tons and required a room of 1500 square feet, consisting of over 6000 switches and 18,000 vacuum tubes.
1954: JOHNNIAC, a smaller computer completed with over 5000 vacuum tubes, weighed 2 tons and was used for scientific and engineering research.
1960s: The Programmer 101 became the first desktop computer available to consumers, weighing 65 pounds and featuring 37 keys with a built-in printer.
1970s: The Xerox Alto introduced email and printing capabilities to personal computers and was one of the first to use a mouse, keyboard, and screen.
1984: Apple Macintosh was launched, combined with a keyboard, mouse, and a 9-inch screen, priced at $2495.
1998: The iMac G3 further revolutionized computers with its design and USB ports.
2008: The introduction of the MacBook Air marked a significant advancement in laptop technology, with a thickness of only 0.76 inches, retailing at $1799.
2018: A notable shift in consumer technology was observed with the sale of 33 billion tablets.

Components of Computers

The internal components of computers can be categorized into various sections:

Microprocessor: The microprocessor acts as the brain of the computer and operates through three key stages:

Fetch: In this stage, an instruction or piece of data is loaded from memory into the CPU's register. It is essential for all instructions to be fetched before execution.
Decode: Decoding converts the fetched code into a format suitable for upcoming processes.
Execute: Execution refers to the process by which the computer performs the instructions from a program.

Memory: Memory is categorized into primary and secondary:

Cache Memory: This chip-based component enhances the efficiency of data retrieval from the computer's memory.
Primary Memory: The main memory of the computer where data is stored temporarily, allowing direct access by the CPU.
Secondary Memory: This external storage saves data permanently but cannot be directly accessed by the CPU.