Computer & Main Parts of Computer – Input, CPU & Output Devices

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A Computer is a General purpose machine, commonly consisting of digital circuitry, that accepts (inputs) , stores, manipulates, and generates (outputs) data as numbers, text, graphics, voice, video files, or electrical signals, in accordance with instructions called a program.

  • Father of the computer - Charles Babbage
  • Father of the modern computer - Alan Turing
  • Basic Architecture of Computer: John Von Neumann (1947 - 49)
  • First Programmer: Lady Ada Lovelae (1880)
  • First Electronic Computer: ENIAC (1946) - J. P. Eckert & J. W. Mauchly
  • First computer for the home user introduced - IBM in 1981

Main Parts of Computer

Hardware - Computer hardware is what you can physically touch includes the computer case, monitor, keyboard, and mouse. It also includes all the parts inside the computer case, such as the hard disk drive, motherboard, video card, and many others.

Input Devices

  • Input Devices - In computing, an input device is a peripheral (piece of computer hardware equipment) used to provide data and control signals to an information processing system such as a computer or information appliance. Examples: keyboards, mice, scanners, digital cameras and joysticks.
  • Keyboard – A Keyboard is the most fundamental input device for any computer system. It helps to enter data in computer.
  • Mouse - A mouse is used to input data by sending a signal to the computer, based on hovering the cursor and selecting with the left mouse button. The left mouse acts as a ‘enter’ button. The right mouse button can be selected and will often pop up a window of choices. The scrolling wheel is used to move the view of the screen up or down. By moving your mouse to a location in a document, on a digital photo or over a choice of music, you can click the left mouse button to place the cursor.
  • Trackballs - A trackball is an input device used to enter motion data into computers or other electronic devices. It serves the same purpose as a mouse, but is designed with a moveable ball on the top, which can be rolled in any direction. Instead of moving the whole device, you simply roll the moveable ball on top of the trackball unit with your hand to generate motion input.
  • Barcode reader - A barcode reader (or barcode scanner) is an electronic device that can read and output printed barcodes to a computer. Like a flatbed scanner, it consists of a light source, a lens and a light sensor translating optical impulses into electrical ones.
  • Digital camera - a camera which produces digital images that can be stored in a computer and displayed on screen.
  • Gamepad - a handheld controller for video games.
  • Joystick - a lever that can be moved in several directions to control the movement of an image on a computer or similar display screen. It mainly used in playing games.
  • Microphone - an instrument for converting sound waves into electrical energy variations which may then be amplified, transmitted, or recorded.
  • Scanner - a device that scans documents and converts them into digital data.
  • Webcam - a video camera connected to a computer, allowing its images to be seen by Internet users.
  • Optical character recognition (OCR) - is the mechanical or electronic conversion of images of typed, handwritten or printed text into machine-encoded text.
  • Digitizer: It converts analog information into digital form.
  • Optical Mark reading (OMR) : Optical Mark Readers reads pencil or pen marks made in pre-defined positions on paper forms as responses to questions or tick list prompts.

CPU (Central Processing Unit)

  • A central processing unit (CPU) is the electronic circuitry within a computer that carries out the instructions of a computer program by performing the basic arithmetic, logical, control and input/output (I/O) operations specified by the instructions.
  • CPU – Heart of the Computer

CPU Process:

  • Fetch the Instruction
  • Interpret the Instruction
  • Fetch the Data
  • Process the Data
  • Write the data

Basic Structure of CPU

Basic Structure of CPU

Output Devices

  • An output device is any device used to send data from a computer to another device or user. Most computer data output that is meant for humans is in the form of audio or video. Examples include monitors, projectors, speakers, headphones and printers.
  • Monitors - A Monitor is a TV-like display attached to the computer on which the output can be displayed and viewed. It can either be a monochrome display or a colour display.

Monitor & Its Types

  • CRT (Cathode ray tube) - The cathode ray tube (CRT) is a vacuum tube containing one or more electron guns, and a phosphorescent screen used to view images.
  • Thin-Film-Transistor Liquid-Crystal Display (TFT LCD) - A thin-film-transistor liquid-crystal display (TFT LCD) is a variant of a liquid-crystal display (LCD) that uses thin-film transistor technology to improve image qualities such as addressability and contrast.

Printer - Printer is an output device for printing text or pictures.

  • Impact printer - An impact printer is a printer that strikes a print head against an ink ribbon to mark the paper. Common examples include dot matrix and daisy-wheel printers.
  • Non-Impact printer - Non-impact printers print the characters without using ribbon. Two common types of non-impact printers include inkjet printers, which spray small drops of ink onto each page, and laser printers, which roll ink onto the paper using a cylindrical.