Chapter 1: Introduction of Computer

Chapter 1: Introduction of Computer

1.1 Introduction of Computer

1.1.1 Definition, Characteristics, and Applications of Computers

Definition:
A computer is an electronic device that processes data, performing calculations and executing instructions to produce meaningful information. It can store, retrieve, and manipulate data efficiently.

Characteristics:

1. Speed: Computers can perform millions of calculations per second.
2. Accuracy: They provide accurate results, minimizing human errors.
3. Automation: Once programmed, computers can perform tasks automatically without human intervention.
4. Storage Capacity: Computers can store vast amounts of data.
5. Versatility: They can perform various tasks, from simple calculations to complex simulations.
6. Diligence: Computers can work continuously without fatigue or loss of concentration.
7. Connectivity: They can connect to networks and the internet, facilitating data sharing and communication.

Applications:

• Business: Managing finances, inventory, and customer relations.
• Education: E-learning platforms, research, and digital classrooms.
• Healthcare: Patient record management, diagnostics, and telemedicine.
• Entertainment: Gaming, multimedia, and streaming services.
• Science and Engineering: Data analysis, simulations, and modeling.

1.1.2 Evolution of Computer Technology

The evolution of computer technology can be traced through several generations, each marked by significant advancements:

1. First Generation (1940-1956): Used vacuum tubes for circuitry and magnetic drums for memory. Examples: ENIAC, UNIVAC.
2. Second Generation (1956-1963): Transistors replaced vacuum tubes, making computers smaller and more efficient. Examples: IBM 7094, CDC 1604.
3. Third Generation (1964-1971): Integrated circuits (ICs) emerged, allowing more components to fit on a single chip. Examples: IBM System/360.
4. Fourth Generation (1971-Present): Microprocessors were developed, leading to the personal computer (PC) revolution. Examples: Intel 4004, Apple Macintosh.
5. Fifth Generation (Present and Beyond): Focuses on artificial intelligence, machine learning, and quantum computing. Current technologies include neural networks and advanced algorithms.

1.1.3 Measurement Unit of Processing Speed and Storage Unit

Processing Speed:

• Measured in Hertz (Hz), representing the number of cycles per second.
  • Kilohertz (kHz): 1,000 Hz
  • Megahertz (MHz): 1,000,000 Hz
  • Gigahertz (GHz): 1,000,000,000 Hz

Storage Unit:

• Bit: Smallest unit of data (0 or 1).
• Byte: 8 bits.
• Larger units include:
  • Kilobyte (KB): 1,024 Bytes
  • Megabyte (MB): 1,024 KB
  • Gigabyte (GB): 1,024 MB
  • Terabyte (TB): 1,024 GB

1.1.4 Supercomputers, Mainframe, Mini, and Microcomputers

1. Supercomputers:

   • High-performance systems used for complex computations (e.g., weather forecasting, scientific simulations).
   • Example: Summit, Fugaku.

2. Mainframe Computers:

   • Large and powerful systems capable of processing and storing vast amounts of data.
   • Typically used in large organizations for bulk data processing (e.g., banking).
   • Example: IBM zSeries.

3. Minicomputers:

   • Mid-range computers, smaller than mainframes but larger than microcomputers.
   • Used for small to medium-sized businesses.
   • Example: PDP-11.

4. Microcomputers:

   • Personal computers designed for individual use.
   • Include desktops, laptops, tablets, and smartphones.
   • Example: Dell Inspiron, Apple MacBook.

1.1.5 Mobile Computing and its Applications

Mobile Computing:

• Refers to the ability to use computing devices while on the move, utilizing wireless networks.
• Involves portable devices like smartphones, tablets, and laptops.

Applications:

• Communication: Instant messaging, video calls, and emails.
• Navigation: GPS services for real-time location tracking.
• Mobile Banking: Financial transactions via banking apps.
• Social Media: Accessing platforms like Facebook, Instagram, and Twitter.
• E-commerce: Online shopping through mobile applications.

1.2 Computer System and I/O Devices

1.2.1 Concept of Computer Architecture and Organization

• Computer Architecture: Refers to the design and structure of a computer system, including its hardware components and their interactions.
• Computer Organization: Describes the operational units and their interconnections in the architecture.

1.2.2 Components of Computer System

1. Input Unit: Accepts data and instructions from the outside world (e.g., keyboard, mouse).
2. Output Unit: Sends processed data to the outside world (e.g., monitor, printer).
3. Processing Unit: Performs calculations and logical operations (e.g., CPU).
4. Memory Unit: Temporarily holds data and instructions (e.g., RAM).
5. Storage Unit: Stores data permanently or semi-permanently (e.g., hard drives, SSDs).

1.2.3 Microprocessor: Basic Concepts, Clock Speed, Word Length, Components, and Functions

• Microprocessor: The brain of a computer that performs computations and processes instructions.
• Clock Speed: Measured in GHz, it indicates how many cycles per second the processor can execute.
• Word Length: The number of bits the processor can process in a single operation (e.g., 32-bit, 64-bit).
• Components: Includes ALU (Arithmetic Logic Unit), Control Unit, and registers.
• Functions: Executes instructions, performs calculations, and controls data flow within the computer.

1.2.4 Bus System: Data Bus, Address Bus, and Control Bus

• Bus System: A communication system that transfers data between components.
  • Data Bus: Transfers actual data between components (e.g., CPU, memory).
  • Address Bus: Carries memory addresses from the CPU to other components, specifying where data should be sent or retrieved.
  • Control Bus: Transmits control signals from the CPU to manage the operations of other components.

1.2.5 Primary Memory

• Definition: Temporary storage that provides fast access to data.
• Types:
  • RAM (Random Access Memory): Volatile memory used for temporary data storage.
  • ROM (Read-Only Memory): Non-volatile memory used for permanent storage of firmware.
  • Cache: A smaller, faster type of volatile memory that stores frequently accessed data.
  • Buffer: Temporary storage used to hold data while it is being transferred between two devices.

1.2.6 Secondary Memory

• Definition: Non-volatile storage used for permanent data storage.
• Types:
  • Magnetic Disk: Hard drives and floppy disks that use magnetic storage.
  • Flash Memory: USB drives and SSDs that use flash memory technology.
  • Optical Disk: CDs, DVDs, and Blu-rays that use laser technology for reading and writing data.
  • External Storage Devices: Devices like external hard drives and memory cards.
  • Memo Stick: A form of removable flash memory.

1.2.7 Input Devices

• Devices that allow users to enter data into a computer system.
  • Keyboard: Standard input device for text and commands.
  • Mouse: Pointing device for graphical interfaces.
  • Scanner: Converts physical documents into digital format.
  • Light Pen: A pointing device used for selecting objects on a screen.
  • OMR (Optical Mark Recognition): Reads marked answers on documents (e.g., answer sheets).
  • OCR (Optical Character Recognition): Converts printed text into digital text.
  • BCR (Barcode Reader): Scans barcodes for data input.
  • MICR (Magnetic Ink Character Recognition): Reads special characters printed with magnetic ink.
  • Touch Screen: Allows direct interaction with the display.
  • Microphone: Captures audio input.
  • Digital Camera: Captures images and videos for input.

1.2.8 Output Devices

• Devices that convey information from a computer to the user.
  • Monitor: Displays visual output; types include LCD and LED.
  • Printer: Produces hard copies; types include Dot Matrix, Inkjet, and Laser.
  • Speaker: Outputs audio signals.

1.2.9 Hardware Interfaces

• Connections that allow different hardware components to communicate with each other.
  • Parallel Port: Used to connect printers and other peripherals.
  • Serial Port: Transfers data one bit at a time, often used for older devices.
  • USB Ports: Universal interface for connecting various devices like flash drives and keyboards.
  • HDMI: High-Definition Multimedia Interface for transmitting audio and video.
  • Expansion Slots: Allow additional hardware components (e.g., graphics cards, sound cards) to be added to the motherboard.