Introduction

Computers are there in our everyday life. So is in work place. No Banking in todays time can happen without Computer Programs. It is highly essential for a bank employee to have a thorough knowledge about Computers and its various applicaitons. The Government and Bank PO jobs entrance exam has Compuuter Knowledge as a compusory criteria to pass and get the job. Laqshya brings you free of cost Text Notes so that you can prepare in a best possible manner and understand the Computers Subject in depth. Moreover, we had also published a full fledged Computers Glossary on this website.

Team - Laqshya ..

What you will learn

Our Main goal is to make Computers easy for every student to understand. In this section you will learn :

• Computers indepth Knowledge
• Improve your skills in definitions
• Glossary to understand every word and its meaning
• Became an exeprt in limited time

1.      Input Devices

Input devices are all those hardware equipment that are used to enter data into the computer. Various type of input devices are listed below with explanations to understand clearly.-

Keyboard - This is the most common and widely used input device. There are different types of keyboards but the QWERTY keyboard is the most widely used. Apart from the normal alphabetical keys, the keyboard has:

-          A Numeric Keypad

-          Navigation Keys

-          Function Keys

Mouse or Trackball - The second most commonly used input device is the mouse.   The mouse helps the user to point and access items on the computer.   Its main function is to control the cursor or pointer on the computer�s screen. The mouse can have 2 or 3 buttons, used according to the software application being used.   Today, most mice also have a scroll wheel which is used mainly to scroll through documents.

The trackball has the same basic functions of the mouse. The only difference is that the trackball is stationary and one doesn�t need to move it on a mouse pad. In order to navigate with the pointer, the user must move a ball situated at the top of the device. Similar to the mouse, the trackball has 2 or 3 buttons used to select items from the screen.

Touchpad - This is a small sensitive pad used on portable computers (laptops). The touch pad is used as a pointing device. The pointer is moved on screen by touching the touch pad with the finger. Tapping on the touch pad will give the same results as when using the mouse buttons. The touchpad is particularly useful for persons with disability whom can have limitations in moving their hand.

Scanner -The scanner is a device that transfers printed text and images to a computer. Today, most home users have a scanner connected to their computers. These are generally called flatbed (others less common such as barcode readers are called handhelds). The scanner alone is not enough to capture the data and transform it to a format that can be understood by the computer.

Joystick - This device is well known with young people as it is mainly used for playing computer games. As the name implies, it is like a stick connected to a platform, which can be moved in all directions. These movements in turn will move something on screen depending on the game.   Usually joysticks have buttons also called triggers.

Barcode Reader - When we buy products from shops we usually see small labels containing white and black stripes called barcodes. These labels contain information on the product.   In order to read this information, one must pass the barcode in front of a special reader.   This reader can be in a form of a pen or installed on the shop�s counter.   The barcode reading consists of a light emitting diode that will emit light on the code. The reflected light from the barcode is translated to the computer by a light sensitive diode.

Optical Mark Reader - This device reads marks in predetermined places on specially prepared cards.   These are usually used in multiple-choice questions. The student will have to fill a space with a pencil, usually HB. The filled examination paper is then inserted into the OMR so as to enable it to read the answers marked.

Magnetic Ink Character Reader (MICR) - This system uses special ink to write numbers with coded magnetic ink. This special ink contains the written numbers magnetically. This system is widely used on cheques issued by banks.   The MICR is much faster than OCR or other methods when reading codes and thus identifying cheques.

Graphics Table - Professionals, such as draftsmen and engineers, usually use this input device.   It is used to speed up their drawing work. The device consists of a hand held operated device (similar to a pen) used to trace diagrams placed on a digitized table. The drawing will then be transferred to the computer.

Pen - Pens are used on hand held computers such as PDA�s (Personal Data Assistant).   These hand held computers have a special sensitive screen. When the user touches the screen it will interact with the computer

Summary of Input Devices -

Input Device	Advantages	Disadvantages
Keyboard	Typists can use with ease	Relatively slow
Mouse	No typing skills are required	At times can be tricky to use
Light Pen	No typing skills are required	Needs much software to make it versatile
Bar Code Reader	Quick and easy entry of data	Needs specialized software under non-ideal conditions
OCR	Can be programmed to read	Elaborate hardware and text and neat handwriting software required, needs training
Mark Reader	Fast input	Elaborate hardware and software required
MICR	High volume, very reliable	Only 14 characters are represented
Joystick	Easier than keyboard	Special interface needed
Digital camera	Easy image capture	Still relatively costly
Graphics Tablet	Enables operator to enter pictures	Slow
Speech Reader	No hands needed	Limited vocabulary
Touch Screen	Easy operation	Needs specialised hardware Intuitive and software
Hand Held Terminals	Can have add-ons for sophisticated operations	Relatively slow
Scanner	No artistic performance required	High quality graphics require large amounts of disk space

 

 

 

 

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