Monday, August 10, 2020

Computer Basics: Input Output Devices

Computer Input-Output devices: Dear Readers, today Testexam.in is going to write an article about Computer Input-Output devices in this post. We will tell you all the list of Computer Input-Output devices & system. Computer Input-Output Devices, we have already explained the computer introduction and Computer Abbreviations in computer basics course.

Computer Input-Output Devices

Input-Output devices:

  • An Input-Output system in a computer is required to put instructions as data into the system and to get
    information to the system.
  • An input system in a computer has two basic programs:

CPU<——System Bus——-> Main Memory <—–System Bus—–> Input-output Module/devices

Input Devices

The devices which are used to put instructions or data into the system are known as input devices.
eg: Keyboard, Mouse, Trackball, Joy Stick, Light Pen, Mic, WebCam, Scanner, OMR, DBR/BCR, OCR, MICR etc.

Keyboard:

It is a standard input device which is based on QWERTY typewriter. A normal keyboard has 104 keys.

Mouse:

  • It is an input device which is a pointing device used to move a pointer on to the screen.
  • A normal mouse has two buttons i-e, left button and right button. Behind this trackball is available to move the pointer of the mouse on the screen.
  • Nowadays optical Mouse is available which has three buttons including a scroll button to move the screen up and down. Behind these lessors is available to move the mouse pointer to screen.
  • Founder of Mouse: Douglas C. Engelbart in 1964

Track Ball:

It is an input device which is pointing device used to move a pointer on to the screen. Nowadays it is outdated.

Joy Stick:

It is an input device which is a pointing device. Mostly use to play games to move the pointer UP & Down and Left & Right.

Light Pen:

  • It is an input device which is a painting device looks like an ordinary pen which as an optical tip from where the laser is emitted.
  • Full form of a LASER: Light Amplification by Stimulated Emission of Radiation

Mic:

It is an input device which is used to put voice & Audio instructions into the system.

WebCam:

It is an input device which is used to put graphics & Audio instructions into the system.

Scanner:

It is an input device which is referred to an eye of the computer system. It scans images, put into the system.

OMR: Optical Mark Reader/Recognition:

It is an input device which is used to read to computer-readable papers i-e OMR Sheets.

OBR: Optical Bar Reader/ Optical Bar Code Reader

It is an input device which is used to read a set of vertical bars of different widths for specific data entry.

OCR: Optical Character Recognition:

It is an input device which is used to recognize the shape & size of characters or symbols.

MICR: Magnetic Ink Character Recognition:

It is an input device which is used by banking industries to read cheque numbers directly and necessary processing.

Output Device

The device which is used to get information from the system is known as output devices.
eg: Monitor, Printer, Plotter, Speaker etc.

Monitor:

It is a primary output device which is also known as VDU (Visual Display Unit).

According to display technology, there are mainly three types of Monitor:
CRT: cathode ray tube
LCD: LED, TFT, HD
PD: Projection Display

CRT and LCD

LCD has the quality of low energy consumptions. The display quality of LCD was relatively poor then CRT but nowadays its quality has been enhanced. CRT & LCD are commonly referred to as the probable device. LCD is more costly than CRT.

PD: Projection Display

PD are popularly used as overhead monitors which are mainly used for the seminar, Marketing, representation classroom study etc.

According to adaptor’s i-e, graphics card implementation, the types of monitor are:
MGA: Monochrome Graphics Adaptor
CGA: Color Graphics Adaptor
HGA: Hercules Graphics Adaptor
SVGA: Super Video Graphics Adaptor

Printer:

It is an output device. we will explain in the next topics about the printer & its type.

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