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The Evolution of Computers Developed initially by the University of Manchester, early Definition: transistor computers emerged around 1953. A computer is a p...

The Evolution of Computers Developed initially by the University of Manchester, early Definition: transistor computers emerged around 1953. A computer is a programmable device for processing, storing, and 3. Third Generation (Integrated Circuits) : retrieving data, enabling global connectivity and transforming the Jack Kilby at Texas Instruments invented the integrated circuit world. (IC) in 1958, enabling multiple components on a single chip. History: ICs allowed smaller, cheaper computers to be accessible to the The term “computer” originally referred to a person performing public, with users interacting through keyboards, monitors, manual calculations. and operating systems for multi-application processing. 1940s-1950s: Early digital computers were massive machines filled 4. Fourth Generation (Microprocessors): with thousands of vacuum tubes, with very limited computational The Intel P4004 microprocessor (1969) condensed computer abilities compared to modern personal computers. functions onto a single chip, integrating the CPU, memory, Types of Computers: and I/O controls. Digital Computers: These operate data sequentially in binary (0 and Microprocessors reduced computer sizes to fit in the palm of 1). Each binary digit is represented by a transistor. a hand, contrasting the room-sized first-generation computers. Analog Computers: Data representation mirrors the properties of the Components of Computers data, using physical quantities like voltage for calculations. Analog Input Unit: Takes user commands in data format (e.g., keyboards, mice) and data is often corrupted by noise, making digital data more reliable. converts them into digital language for processing. Pioneers in Analog Computers: Central Processing Unit (CPU): James Thomson: Created early analog computing devices, including Memory Unit: Stores incoming data and outputs data, using bits and a wheel and disc integrator for mechanical analog calculations. bytes to measure data size. Lord Kelvin: Worked with Thomson on a device for integrating Control Unit: Directs the system’s functions, converting data into functions and designed a tide-predicting machine used until the 1960s. machine language and managing data flow to the ALU. Vannevar Bush: Developed the Differential Analyzer, a general- Arithmetic-Logical Unit (ALU): Handles all mathematical purpose analog computer that occupied a large table and weighed 100 operations and data comparison, performing calculations only when tons. It contained wheels, discs, shafts, and gears for calculations but required and sending results to the output unit. was eventually phased out post-WWII. Output Unit: Displays processed data (e.g., monitors, printers), Generations of Digital Computers completing the user-system interaction. 1. First Generation (Vacuum Tubes) : Operating Systems Early computers used thousands of vacuum tubes, bulky 1. Definition: An operating system (OS) is software that makes three-terminal devices with cathode, grid, and plate. computer hardware usable, managing system performance and Examples include the Atanasoff-Berry Computer (ABC), resources for users. Colossus, ENIAC, UNIVAC I, and IBM 701. 2. Examples of Operating Systems: 2. Second Generation (Transistors): Microsoft Windows: Dominates the PC market with over Transistors replaced vacuum tubes, significantly reducing 90% share but has minimal impact on mobile markets. size, cost, and power consumption. Mac OS: Created by Apple for Macintosh computers, offering multitasking and memory security.  Mobile OS: Includes Google’s Android for touch devices and Domain Name System (DNS): Created by Paul Mockapetris, Apple’s iOS, derived from Mac OS, widely used in iPhones. Jon Postel, and Craig Partridge; symbolics.com became the 3. Advantages of Operating Systems: first registered domain in 1984. Abstraction: Hides complex hardware details. 3. 1990s: Executable Programs: Provides a stable environment for Decommissioning of ARPANET: The internet expanded to running applications. the public sector. User-Friendly Interface: Simplifies user interaction with the World Wide Web: Tim Berners-Lee’s development of system. HTML and URLs enabled the creation of the first website. 4. Disadvantages of Operating Systems: Commercial Internet: Windows 95 popularized the internet; Volatility: Risk of data loss if issues arise. companies like Amazon and Yahoo emerged, and Java Cost: Can be expensive for small organizations. enabled interactive content. Security: Threats can compromise data at any time. 4. 2000s: The Power of the Web and the Internet Dot-Com Bubble: Heavy investment in internet startups led to 1. Web vs. Internet: a crash in 2001. Web (World Wide Web): A system of interconnected web Search Engine and Wi-Fi Expansion: Google emerged as the pages linked via hypertext and hypermedia. top search engine; Wi-Fi and mobile internet access surged Internet: A network infrastructure connecting millions of with smartphones. computers globally, facilitating data communication. How the Web and the Internet Changed the World 2. History of the Web: 1. Communication: Tim Berners-Lee: Developed the WWW in 1989 at CERN, Revolutionized global communication via email and social media, using hypertext to create a global information system. allowing instant interaction but increasing risks of impulsive First Website: Launched August 6, 1991, introducing messaging. hypertext and web servers. 2. Information Access: Expansion: By 1993, NCSA released browsers compatible Search engines and e-books made knowledge widely accessible, with PCs and Macs, leading to widespread adoption. although misinformation, or “fake news,” has become a significant Brief History of the Internet issue. 1. 1960s: 3. Entertainment: Social media, online gaming, streaming services (e.g., Netflix, J.C.R. Licklider: Conceptualized a global network. Spotify) transformed entertainment, though overuse can harm social Packet-Switching: Developed by Leonard Kleinrock, connections. Thomas Merrill, and Lawrence G. Roberts, leading to 4. Education: ARPANET, the first wide-area network. During COVID-19, the internet enabled online learning through video 2. 1980s: conferencing and platforms like NEO eLMS, although students risk PhoneNet and Telenet: PhoneNet linked ARPANET and becoming overly reliant on digital learning environments. Telenet, broadening email access globally.