History of Computers

• Abacus stores values with bead positions on rods and it is known as the earliest counting tool
• Leibniz's Machine used gears for arithmetic and represented data by gear positioning
• Babbage's Analytical Engine was designed to read instructions and perform calculations using paper cards
• Ada Lovelace was the first programmer and developed the first algorithm for Babbage's machine

First Electronic Computers

• ENIAC (1946) was the first programmable computer
• ENIAC used vacuum tubes making it big, slow, and power-hungry

Desktop Computers (1970s-1980s)

• Apple (1976) was created when Steve Jobs & Steve Wozniak developed early personal computers
• IBM PC (1981) helped popularize computers for business and home use
• Microsoft developed software for computers

Generations

• First Generation (1946-1959) used vacuum tubes and magnetic drums for memory, relying on machine language with punch cards for input/output
• Second Generation (1959-1965) replaced vacuum tubes with transistors, which were more reliable and economical
  • This generation introduced tapes and disks for storage
  • High-level programming languages like FORTRAN and COBOL began use in this generation
• Third Generation (1965-1971) used integrated circuits (silicon chips) and introduced the floppy disk for storage
  • Users could interact with computers using keyboards and monitors from this generation onwards
  • Operating systems were introduced allowing multiple applications to run simultaneously
• Fourth Generation (1971-Present) introduced microprocessors, graphical user interfaces (GUIs), and handheld devices
  • High-level languages and application software became widely used
  • Operating systems like Microsoft Windows were developed
• Fifth Generation (Emerging Technology) focuses on AI, quantum computing, ultra-large-scale integration (ULSI), and nanotechnology
  • Quantum computing reduces power consumption
  • Natural language processing (AI) allows for more human-like computer interactions

Computer Components

• Central Processing Unit (CPU) processes information and executes commands
  • CPU speed is measured in GHz
• Random Access Memory (RAM) provides temporary storage that is lost when the computer is powered off (volatile memory)
• Read-Only Memory (ROM) provides permanent storage that contains essential system instructions (non-volatile memory)
• Hard Drive stores data permanently, with HDD (spinning disk) and SSD (faster, no moving parts) options
• Graphics Processing Unit (GPU) renders images, graphics, and videos used in gaming and video editing
• Expansion Cards provides extra abilities like graphics cards or sound cards

Input, Output, and Storage Devices

• Input devices give data to the computer such as keyboards, mice, and scanners
• Output devices get results from the computer such as monitors, speakers, and printers
• Storage devices save data such as SSDs, HDDs, and flash drives

CPU Breakdown

• Arithmetic Logic Unit (ALU) performs math and logic operations
• Control Unit tells all parts of the CPU what to do
• Processor Register provides tiny storage for quick access to data

Buses (Data Highways)

• Address Bus identifies where data should go
• Data Bus transmits the actual data
• Control Bus sends commands to control data flow
  • Address Bus is like GPS directions
  • Data Bus is like cars carrying data
  • Control Bus is like traffic signals controlling flow

Registers

• Memory Address Register (MAR) holds the memory location of data to be accessed
• Memory Data Register (MDR) holds data being transferred
• Accumulator (AC) stores results from the ALU
• Program Counter (PC) stores the address of the next program instruction
• Current Instruction Register (CIR) holds the instruction currently being executed

Motherboard and System Clock

• Motherboard is the main circuit board connecting all parts
• System Clock sends electric pulses to keep everything running on time

Storage and Expansion

• Secondary Storage stores data permanently using HDDs, SSDs, CDs, and DVDs
• Expansion Slots & Ports are used to add new parts using USB, HDMI, and Ethernet

Connectivity

• Modem allows communication over phone lines
• Network cables provide direct connections between devices
• Satellite enables wireless signal from space
• Wi-Fi provides wireless internet connection
• Bluetooth allows short-range wireless communication (like AirPods)

Computer Types

• Supercomputers are used for scientific simulations, weather forecasting, and nuclear energy research
• Mainframe Computers handle large amounts of data for big organizations, like banks and airlines
• Workstations are built for technical and scientific applications, such as graphic design, music production, and engineering
• Microcomputers are for personal use, including desktops and laptops

Computing Advancements

• Quantum Computing uses non-classical computing to increase processing power while reducing energy consumption
• Nanotechnology involves molecular-level tools to improve hardware
• AI & Natural Language Processing allows computers to understand and respond to human language