| 摘要 |
<p>1283747 Data processing; credit verification DIGITAL DATA SYSTEMS CORP 15 Oct 1969 [21 Oct 1968] 50758/69 Headings G4A and G4T A system which verifies customers' credit status in response to entry of a charge account number at any one of a plurality of remote stations comprises a central processor 10 having storage means suitable for storing charge account numbers and a plurality of terminal units 13 to 18 at said remote locations each having means for encoding the charge account number to be verified, wherein the terminal units are connected to the central processor by way of distributers 19, each terminal unit being connected to its distributer by way of only two information lines. As there are only two lines the system is asynchronous, though a third clockpulse wire may be added to make the system synchronous. A magnetic drum in unit 10 stores electrical signals representing the numbers to be honoured or not to be honoured, or all numbers with their respective credit ratings. By means of a drum interface 11 and a teletype print station 12 the records can be updated and transactions recorded respectively. Up to 100 terminal units 13 to 18, situated for example in department stores, are provided each of which has a keyboard or a credit card reader (e.g. a card reader matrix, Fig. 4a, not shown, photoresistive cells, or buffered photo voltaic or photodiode or photo transistor cells) by which a card number can be entered, and circuitry for encoding the number serially by bit. The numbers are sent to a distributer including a time division multiplexer, for example 19, servicing a number of terminal units by a two-wire line, for example a telephone line, and thence by way of further distributers 20, 22 to the processor 10. Here the coded number is compared with the memory numbers and, if the credit rating is satisfactory, a signal is sent to the terminal unit which causes the credit card to be embossed. If not, the card is rejected or failure otherwise indicated. Keyboard entry authorizer units with visual display gives account number and reasons for blacklisting can be used to enter or delete numbers from the memory and to enquire whether a number is in the memory and the reason therefore and this is claimed in Specification 1,283,748 which has the same disclosure. The number is coded in split phase, or Manchester code and erroneous signals may be resent.</p> |
