Understanding Computer Basics

• A computer is an electronic device that processes, stores, and retrieves data.
• Core functions of a computer include accepting and storing data, processing it, generating output, performing calculations, and interacting with users.

Advantages of Computers

• High Speed: Processes millions of instructions per second.
• Accuracy: Provides a high degree of accuracy, with errors mainly due to human factors.
• Storage Capability: Can store and retrieve large volumes of data.
• Diligence: Operates continuously without tiring.
• Versatility: Performs a wide range of tasks efficiently.
• Multitasking: Executes multiple tasks simultaneously.
• Automation: Performs tasks autonomously using AI.
• Reduction in Paper Work: Contributes to paperless operations.

Disadvantages of Computers

• No I.Q.: Lacks independent intelligence.
• Dependency: Requires user commands.
• No Feelings/Emotions: Is devoid of emotions.

Applications of Computers

• Applications include Education, Business & Marketing, Health care, Military, Design, Space, and Communications & Media.

Brief History of Computing

• Abacus: Used nearly 5000 years ago in Babylon.

Mechanical Computers

• Pascaline (1640s): Early mechanical calculator.
• Stepped Reckoner (1670s): Another early mechanical calculator.

Electronic Computers: Evolution Through Generations

• First Generation (1940s): Used vacuum tubes.
  • Predominant features include use of machine code, vacuum tube tech, being unreliable, costly, bulky, and electricity-intensive.
• Second Generation (1959-1965): Used transistors.
  • Characterized by use of transistors, being more reliable and smaller, less heat and electricity usage, and programming languages like FORTRAN and COBOL.
• Third Generation (1965-1971): Used integrated circuits.
  • Integrated circuits were used
  • Higher-level languages were supported such as FORTRAN, COBOL, PASCAL, BASIC, ALGOL-68
• Fourth Generation (1971-1980): Used VLSI microprocessors.
  • VLSI circuits contained 1000s of transistors
  • This gave rise to the personal computer (PC) revolution
• Fifth Generation (1980-onwards): Used ULSI microprocessors and AI.
  • Includes advancements like ULSI technology, AI development, natural language processing, and parallel processing.

Computer Classification Based on Data Handling type

• Computers are classified into three types based on the type of data they can handle: Analog, Digital, and Hybrid.

Analog Computer

• Works on the principle of measuring, translating measurements into data, these measure continuous physical magnitudes.
• Modern versions use electrical parameters like voltages, resistances
• The Polish analog computer AKAT-1 could solve relatively complex differential equations in real time.

Digital Computers

• High-speed electronic devices use binary code
• Consists of 0s and 1s, to process data and execute instructions.
• Are used in a wide range of fields and applications and have the ability to complex high precision calculations

Hybrid Computers

• Are a mix of analog and digital computers.
• Perform quick, efficient high-level calculations, converting analog input to digital for processing.
• Petrol pump - Measurement convert fuel flow into currency rate; is an example

Digital Computer Classification Based on Size and Capacity

• Classifications include: Supercomputer, Mainframe, Mini, and Micro Computer (Personal computer)

Supercomputers

• High-performance computers Process 100 trillion instructions in a second.
• Tasks are split and worked on simultaneously by thousands of processors, and are expensive.
• Applications: Scientific researches and weather broadcasting are key applications
• Tasks (instructions) are split into parts and worked on simultaneously by thousands of processors.

Supercomputers

• The fastest are able to process 100 trillion instructions in a single second.
• Applications: Scientific researches and weather broadcasting
• Tianhe-2 or Milky Way 2 is such an example

Top Supercomputers in the World

• As of a recent listing, notable supercomputers include Fugaku, Summit, Sierra, Sunway TaihuLight, Selene, Tianhe-2A, and Juwels Booster Module.
• TeraFLOPS: Unit of computing speed equal to one trillion floating-point operations per second.

Mainframe (big Iron)

• Powerful standalone systems store huge amounts of data and handle thousands of clients, and comparatively huge as well as take huge space for the entire setup.
• Used by large organizations for critical apps like bulk data processing
• Slower then supercomputers

Minicomputers

• Digital computers used in multi-user systems
• Higher processing speeds
• Support 4-200 simultaneous users via PCs or terminals.
• Used for scientific/engineering, business, file handling and database management
• Evolved in late 1950s, peaked in the 60s/70s
• Reached peak of use in the 60s and 70s

Microcomputers

• Low cost, small, for a single users and are digital computers. Microcomputers includes desktops, laptops, tablets, smartphones, etc.

Computer Types Based on Purpose

• General purpose: Designed to perform a multitude of different tasks (desktops, laptops, etc)
• Specific purpose: Solve specific problems or perform a specific task (weather forecasting, traffic control systems, etc)

Introduction to Computer System

• Computer is an electronic device that accepts data as input, processes it, and gives the desired output.
• Computers consist of software and hardware.
• The users can be: programmers, operators, system analysts and engineers.

Hardware

• Input unit: Allows data and instructions. Ie Keyboard, mouse, scanner, optical, touchpad, screen, joystick, gamepad, webcam, microphone.
• Output unit: Provides output in understandable form.
• CPU: Controls all the functions an operations. Consists of ALU, memory unit and Control Unit (CU)