1.

2 Input devices and media

To gather information from the card, it is swiped e computer system turns each set of marks into

through a machine which quickly and accurately reads numbers and enters them into the draw. is method

the magnetic pattern. If the magnetic area on the card of entering data is called optical mark recognition

is scratched or gets soiled, then the information stored (OMR) and relies on precisely positioned marks on a

on the card can be corrupted. Such a card is used by form being read by a special scanner. is data is then

businesses to reward loyal customers. processed by the system.

A card that does not rely on a magnetic strip is also If you have multiple-choice tests as part of your

now appearing. It has a built-in electronic circuit and examinations, you will probably have to answer them

a set of gold-coloured contacts. Putting the card in on an OMR form. ese answer sheets will be passed

a special reader inputs the information held in the through a scanning system to mark your answers. is

circuit. Such cards are called smar t cards. ey are way of inputting data is fast and accurate. OMR is

more sophisticated than magnetic swipe cards. therefore used to read the data that has been added

and then all the data can be transmitted to the

Although smart cards are often called input devices,

computer automatically. e nal information can then

they are actually simple storage devices. W hen the card

be produced without any need for human inter vention.

is put into a machine, data can be read from the card

or written onto it. A smart card can store much more

data than a magnetic strip.

Smart cards, unlike magnetic-strip-based cards, can

carr y all necessar y functions and information on the

card. erefore, they do not require access to remote

databases at the time of the transaction.

Fig 1.8 Data can be entered into a computer in dierent ways. Lottery slips are

an example of optical mark recognition (OMR)

Optical character recognition (OCR)

Another way of entering handwritten or printed text into

a computer system is to scan the text using an optical

character recognition (OCR) program. e scanned text

is turned into a le that can be edited, reformatted and

Fig 1.7 Smar t cards have a built-in electronic circuit and a set of gold- coloured
reprinted by a word processor.e accuracy of OCR is

contacts

variable and can be poor,particularly if the original pages

to be scanned are of poor quality.

Optical mark recognition (OMR)

ere are various ways of inputting letters, words and OMR and OCR are often used together in a

numbers automatically into a system. For example, when turnaround document . A turnaround document is

you buy a lotter y ticket, you ll in the slip by putting one which has some unique information printed on

lines through sets of numbers on a grid (Fig1.8). is it by a computer with other information which needs

slip is then fed into a machine that reads the marks. to be added to it by a human. It is then fed back

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