Input Device

Online input devices

Online input devices are used in real time processing. In real time processing the input data are processed immediately.

Dumb terminal: these types of devices include one key board and one display unit. They cannot store any kind of information and cannot process any data.

Intelligent terminal: as the name implies these type of input devices store the system data and can process them.

Voice recognition device: recognize the voice.

Touch tone terminal: by this device user can interact with system through touch of the monitor of the system. There are many options available on the screen. User can choose then only by single touch. These types of devices are used in ATM machine, railway stations, mobile etc.

Mouse: Mouse is most popular pointing device. It is very famous cursor control device. It is a small palm size box with a round ball at its base which senses the movement of mouse and sends corresponding signals to CPU on pressing the buttons. Generally it, has two buttons called left and right button and scroll bar is present at the mid. Mouse can be used to control the position of cursor on screen but it cannot be used to enter text into the computer.

    Advantages

• Easy to use.
• Not very expensive.
• Moves the cursor faster than the arrow keys of keyboard.

Keyboard: It is standard input device keyboard allow. A computer user to input letters, numbers and other symbols into a computer and are what allows you to write email.

• Function keys: The function keys or F1 through F12 keys are used in program as shortcut keys to performed tasks.
• Control keys: The control keys are what give you additional control of a document.
• Keypad: Although not available on all computer keyboards especially in laptops the keypad gives the user a quick access to number, and multi functions such as plus divide, times and subtract.
• Arrow keys: finally the arrows keys are four directional arrow keys that allow user to move their cursor and position on a page.

Source data input device

Scanner: Scanner is an input device, which works more likes a photocopy machine. It is used when some information available on a paper and it is to be transfer to the hard disc of the computer for further manipulation. Scanner captures image from the digital from that can be stored on the disc. These images can be edited before they are printed.

OMR (Optical mark reader): OMR is a special type of optical scanner used to recognize the type of mark made by pen or pencil. It is used where one out of a few alternatives is to be selected and marked. It is specially used for checking the answer sheets of examinations having multiple choice questions.

OCR (Optical character reader): OCR is an input device used to read a printed text. OCR scans optically character by a machine readable code and stores the text on the system memory.

MICR (Magnetic character reader): MICR input device is generally used in banks because of a large number of cheques to be processed every day. The banks code number is printed on the cheque’s with a special type of ink that contains particles of magnetic material that are machine readable. This reading process is called magnetic ink character recognition (MICR). The main advantage of MICR is that it is fast and less error prone.

Joystick: joystick is also a pointing device which is used to move cursor position on a monitor screen. It is a stick having a spherical ball at its both lower and upper ends. The lower spherical ball moves in a socket. The joystick can be moved in all four directions. The function of joystick is similar to that of a mouse. It is mainly used in computer aided designing (CAD) and playing computer games.

Tracker ball: Tracker ball is an input device that is mostly used in notebook or laptop computer, instead of a mouse. This is a ball, which is half instead and by moving fingers on ball, pointer can be moved.

Light pen: Light pen is a pointing device which is similar to pen. It is used to select a displayed menu item or draw pictures on the monitor screen. It consists of a photo cell and an optical system placed in a small tube.

Digitizer tablet or graphic tablet: it digitizer is an input device, which converts analog information into a digital form. Digitizer can converts a signal from the television camera into a series of number that could be stored in a computer.

OBR (Optical bar reader): Bar code reader is a device used for reading bar coded data ( Data in from light and dark lines). Bar coded data is generally used in labeling goods, numbering the books etc.

Offline input devices

Keys to card: This is the most former device for data entry. It is store the data inform of punch card. Buffer is used for temporary storage.

Key to tape: This is also known as magnetic tape encoder. In this device we can store data directly by pressing the key. Data are stored temporary before store in the magnetic tape.

Key to disk: this device is used as data are recorded from various points and processed at one point. In this 8 to 64 keyboard stations are connected to a small general purpose computer for storing the data.