Computer Science Overview and Number Systems

Computer Science Overview

• Computer Science focuses on the study of computers and computational systems, emphasizing software systems and their theory, design, development, and application.

Evolution of Positional Number Systems

• Egyptian Number System: Emerged around 3000 BC with a base of 10; symbols represented units, tens, hundreds, and thousands, written from right to left.
• Sumerian/Babylonian System: Utilized a base of 60 and employed blank space instead of a zero.
• Chinese Number System: Developed around 2500 BC; utilized digits 1 to 9, similar to the modern decimal system.
• Greek Ionian Number System: Evolved around 500 BC as a decimal system.
• Roman Numerals: Utilized seven letters (I, V, X, L, C, D) for numerical representation.
• Mayan Number System: Based on 20.
• Hindu-Arabic Numeral System: Originated in India approximately 1500 years ago, is a positional decimal system incorporating the concept of zero, widely adopted globally.

Evolution of Computing Machines

• Abacus: The first computing device created by Mesopotamians around 3000 BC for performing calculations based on a place value system.
• Napier’s Bones: Developed by John Napier in 1617 AD, it simplified multiplication into addition, applicable for digits 2-9.
• Pascaline: Created by Blaise Pascal in 1642, capable of directly adding and subtracting numbers using a series of dialed wheels.
• Leibniz’s Calculator: Developed by Gottfried Wilhelm Leibniz, known as the Step Reckoner, capable of multiplication and division, expanding on Pascal’s design.
• Jacquard’s Loom: Invented by Joseph Jacquard in 1801; utilized punch cards to denote instructions, marking the first use of programmable automation.
• Difference Engine: Mechanical calculator modeled by Charles Babbage in 1822 for computing sets of numbers and producing hard copies.
• Analytical Engine: Developed by Charles Babbage in 1833; featured modern computer elements like a 'Store' (memory) and 'Mill' (processor) and was programmable via punched cards.
• Hollerith’s Machine: Created by Herman Hollerith in 1887, the first electromechanical tabulating device using punched cards, whose designs influenced IBM's future developments.
• Mark I: Designed by Howard Aiken for IBM, it was a large-scale computer capable of performing all arithmetic operations and trigonometric functions.

Generations of Computers

• First Generation (1940-56): Utilized vacuum tubes; included ENIAC and UNIVAC; introduced stored program concepts; primarily bulk and used punched cards for I/O.
• Second Generation (1956-64): Transistor-based; smaller, faster, and less expensive; initiation of programming languages.
• Third Generation (1964-71): Featured Integrated Circuit chips; enhanced speed and efficiency; introduction of keyboards and monitors; emergence of high-level languages like BASIC.
• Fourth Generation (1971-Present): Dominated by microprocessors, further reducing size while enhancing capability and simplicity.