Computer Basics and Components

Introduction to Computer

  • A computer is an electronic device that processes data under stored instructions, accepting input, processing it, producing information, and storing data for future use.

  • It operates using a sequence of program instructions to generate results.

Functionalities of a Computer

  • Input: Accepts data.

  • Storage: Stores data/instructions for later use.

  • Processing: Converts data into useful information.

  • Output: Generates results.

  • Control: Manages the previous steps.

Computer Components

Hardware

  • Refers to physical components like monitors, keyboards, and internal parts (e.g., CPU, RAM).

Software

  • A collection of programs that instruct hardware to perform tasks.

  • Includes applications and operating systems.

Firmware

  • Permanent software programmed into a hardware device for basic functions.

Data and Information

  • Data: Raw facts suitable for processing.

  • Information: Organized, meaningful data, characterized by timeliness, accuracy, and completeness.

Users

  • Individuals who utilize computer systems; often lack deep technical expertise.

Procedures & Communication

  • Procedures are coded instructions for computer operations.

  • Communication media facilitate data transmission (e.g., internet, networking).

Characteristics of Computers

  • Speed: High-performance capability (millions of instructions per second).

  • Accuracy: Low error rates (usually human errors).

  • Diligence: Consistent performance without fatigue.

  • Versatility: Capable of performing a wide range of tasks.

  • Storage Capacity: Ability to store vast amounts of data permanently.

Applications of Computers

  • Used in various fields, including business, education, banking, healthcare, and military.

Classification of Computers

  1. By Application:

  • Analog (continuous data)

  • Digital (discrete data)

  • Hybrid (combination of analog and digital)

  1. By Size:

  • Supercomputers

  • Mainframe

  • Mini

  • Microcomputers

  1. By Brand:

  • IBM, Apple/Macintosh, IBM-Compatible Systems

  1. By Model:

  • XT, AT, PS/2 models.

Mobile Computing

  • Enables data transmission via wireless networks across devices.

  • Comprises mobile communication, hardware, and software.

Input/Output Components

  • Input Devices: Keyboard, mouse, scanner, etc.

  • Output Devices: Monitor, printer, speakers, etc.

Printers

  • Impact Printers: Strikes against ribbons to print (e.g. dot matrix).

  • Non-Impact Printers: Print without striking (e.g., inkjet, laser).

Computer Architecture

  • Composed of I/O unit, CPU (Arithmetic Logic Unit + Control Unit), and memory unit (primary and secondary storage).

  • Data flow between these components maximizes efficiency.

Generations of Computers

  1. First Generation: Vacuum tubes (1946-1959).

  2. Second Generation: Transistors (1959-1965).

  3. Third Generation: Integrated circuits (1965-1971).

  4. Fourth Generation: VLSI (1971-1980).

  5. Fifth Generation: ULSI and AI (1980-present).

Memory

  • Main Memory: Fast but volatile (RAM, ROM).

  • Secondary Memory: Non-volatile storage (hard disks).

Types of Memory Access

  • Sequential Access: In order (e.g. tape).

  • Random Access: Any order (e.g. RAM).

User Interfaces

  • Include hardware (keyboard, mouse) and software interfaces (application language communication).