33 lines
1.7 KiB
Plaintext
33 lines
1.7 KiB
Plaintext
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Interesting article about the danish phonecard system, typed and
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translated from a year round-up issue of Computerworld.
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CARD CHEATERS ARE STOPPED HERE
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You probably don't know but you and your phonecard are being watched
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closely when you're making a call from a cardphone. The phone holds
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on to your card when you insert it into the slot and while you're
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speaking, the computer in the phone is checking and registrering the
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invisible data on the magnetic strip of the card. Everything is
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registrated: The number of the card, the amount you're talking for,
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the time of the call, how long it is and the first digits of the
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called number.
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The computer makes sure that the card isn't used up and the phone
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will immediately eject the card and disconnect the call, if the files
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of valid or black-listed cards show that your card is stolen, a
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forgery or in some other way unusable.
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The computer is pretty velinformed. At least once a day it's updated
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by it's big brother, PMS 200, a central computer. PMS 200 stores the
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numbers of all cards, even before they are put in circulation. At
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this moment PMS 200 is keeping track of approx. five million cards,
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and it follows them through their entire lifetime. All data about
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calls is kept for 30 days, so the technicians of the phonecompany can
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track suspicious cards.
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However, cardphones aren't infallible. Should something go wrong,
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for instance a phone looses it's speaker or chokes on a card, it will
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immediately tell it's other big brother PMS 100, which is constantly
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keeping track of the health of the phones.
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