FR2582123A1 - METHOD FOR RECORDING DATA IN A MEMORY CARD - Google Patents

Abstract

THE INVENTION RELATES TO A MEMORY CARD RECORDING PROCESS. IT RELATES TO A PROCESS ACCORDING TO WHICH THE HIGHER NUMBERS OF A NUMBER TO BE REGISTERED ARE PRESERVED IN A FIRST ZONE OF MEMORY AAJ WHICH CANNOT BE MODIFIED AFTER WRITING, WHILE LOWER DIGITS ARE REGISTERED IN A MEMORY ZONE M WHICH IS MODIFIABLE. IN THIS WAY, THE CARD HAS A GOOD SECURITY FACTOR BECAUSE THE MOST SIGNIFICANT NUMBERS CANNOT BE MODIFIED, WHILE GIVING GREAT FREEDOM AS LOWER NUMBERS CAN BE ADDED AND SUBTRACTED. APPLICATION TO MEMORY CARDS USED FOR PURCHASES.

Description

The present invention relates to a method of

  recording data in a memory card and more specifically a method for storing a consumed amount of a predetermined value in a card-like storage device. The memory card is widely used for recording phone charges, bus trips, copy numbers in a copier, and so on. The use of these types of memory cards is very convenient for buyers instead of coins. When a customer makes a payment with a memory card,

  the quantity consumed of the value corresponding to the

  is saved in the card. Thus, when the total sum corresponding to the quantities consumed reaches a predetermined maximum value, the memory card is considered to be exhausted. In the case of a telephone card, for example, a certain number of calls are recorded in the card each time the customer makes a telephone call. When the recorded number reaches a predetermined maximum number, the calling card becomes depleted. There are two types of memory applicable to a recording area

  a memory card. The first is the modified memory

  a reliable memory, for example a memory formed of a magnetic material, and the other is a non-modifiable permanent memory, for example a fused semiconductor memory, a memory fixed by fusion by a

  laser or a hologram memory that is destroyed.

  When a modifiable memory is used in a memory card, the freedom factor increases so that the recording of any values in

  the memory card and the modification of the stored values.

  can be made freely. However, the safety factor decreases so that it is possible

  recorded data are accidentally lost

  and fraudsters falsify the value recorded

  Tree. As a result, it is dangerous to record

  an expensive value in the card having a modified memory

  reliable. On the other hand, when the memory card has a non-modifiable memory, the security factor is increased because permanent records are formed on the face of the card. However, the freedom factor decreases because the value that can be recorded is

  limited. For example, in a phone card available

  for ten calls, 10 bits of record a to j are arranged on the map as shown in the figure

  1 and are marked one by one each time a tele-

  phonic is performed. When three telephone calls

  the bits a, b and c are marked with crosses, in any way as shown in FIG. 1. The described data recording method is suitable for recording a number of phone calls, train journeys over a particular distance, copies, etc. However, the

  previously described method is not suitable for recording

  the value of various goods purchased,

  having different prices or in the case of the cost of trans-

  port at various distances. For example, in the map

  telephone shown in FIG. 1, a bit

  This is equivalent to a phone call or 1 franc, but the same data logging process can not be used in an acquisition card that can handle fractions of a franc. In such a card, a record bit can represent 1 cent. However, in this case, it takes 10,000 recording bits when the maximum value that can be purchased with the card

  is equal to 100 francs. This number of bits is not reasonable.

sonable.

  As previously described, the recording method

  data of known type does not allow an improvement

  simultaneous ration of both safety factors and freedom factors, so that the process does not

  not suitable for a card that requires both factors.

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  The invention relates to a recording method

  data in a memory card, simultaneously improving

  the two factors of security and freedom.

  More specifically, the method according to the invention first comprises the production of a first recording area comprising non-modifiable memories and a second recording area comprising modifiable memories in a memory card. then saving the upper digits of the value to be stored in the first recording area so

  that the safety factor be increased, and record it

  lower digits of the value in the second recording area so that the factor of freedom

be increased.

  Other features and benefits of

  invention will be better understood by reading the

  following description of embodiments and with reference to the accompanying drawing in which: Figure 1 shows a recording area of a memory card, recorded by implementation of a known method; and FIG. 2 represents a recording area of a memory card recorded by implementation.

of the process according to the invention.

  In FIG. 2, the first recording area

  is formed of 10 record bits a to j which are not modifiable when they have been marked, and the second recording area is constituted by a modifiable memory M. It is assumed that the memory card having these two zones is used as a purchasing card with which a customer can buy goods reaching a total price of 100 francs,

  each record bit corresponding to 10 francs.

  When the customer has purchased goods for 25.7 francs, the quotient 2 and the remainder 27 are obtained by division of 25.7 / 10, 25.7 corresponding to a commodity price and 10 to the quantity assigned to each bit of merchandise. 'recording. Two recording bits a and b are marked with crosses in Figure 2, in a manner

  which corresponds to the quotient 2, these bits not being modified

  reliable, and the number 57 corresponding to the rest 57 is stored in memory M. Then, when the customer purchases goods for 56.5 francs, the quotient and the rest 65 are obtained by division of 56.5 / 10. The five recording bits c, d, e, f and g are marked with a cross as indicated by the reference Y for example, in a manner corresponding to the quotient 5. The remainder 65 is added to the recorded value 57

  in the memory M and the sum obtained is equal to 122.

  Since this exceeds 100, another bit h of record

  is marked with a cross as indicated by the reference

  example, and the remainder 22 obtained by subtracting

  122 is stored in the memory M. Thus, the contents of the memory M are modified and transformed from 57 to 22. Thus, the figures of the tens of francs are recorded in a non-modifiable manner in the first zone of registration so that security is assured, and the figures corresponding to small fractions, corresponding to francs and tens of centimes, are recorded in a modifiable way in the second

  registration area, so that the freedom of registration

  is assured, and the figures corresponding to the

  small fractions are kept accurately.

  In this embodiment, the last record bit is a special bit intended to indicate that the memory card has been exhausted. As a result, the ordinary recording bits for keeping the quotients of the consumed amount correspond to the nine bits of a to i. As described above, after the purchase of the goods of 25.7 francs and the goods of 56.5 francs (corresponding to the total of 82.2 francs), the recording bits a to h have been marked and the fraction 22 has been recorded in memory M. In these circumstances, when the customer wants to buy

  goods for 25 francs, the overflow is detected

  because there is only one ordinary bit of record

  the bit i which is not marked. Whenever the last ordinary bit i is to be marked, the contents of the memory M are always checked so that the recognition of an overflow is determined in a precise manner. So, in the condition described above,

  when the customer tries to spend 19 francs extra

  with the memory card, the following check is performed. The quotient 1 and the remainder 90 are obtained by division of 19/10, and the last ordinary bit i must be marked in a manner corresponding to the quotient 1. The remainder 90 is then added to the value 22 stored in the memory M and the fact that this sum exceeds 100 or not is checked. Since the sum is 112,

  that is, beyond 100 in this example, an overflowing

  is recognized. On the contrary, when the customer wants to spend 17.8 francs in the previous condition, the rest 78 is added to the value 22 recorded in the

  As the sum is just equal to 100, the exhaustion

  memory card is recognized and the special bit

J is marked.

  Although, in the aforesaid method of registering

  the rest of the division is stored in the memory M, another value corresponding to the remainder can also be stored in the memory M. For example, the difference between 100 and the remainder can be recorded

  instead of the rest himself. In this recording process

  when the customer bought goods

  for 25.7 francs, the difference 43 is obtained by sub-

  traction of 57 of 100 and is stored in memory M. Then when the customer bought goods for 56.5 francs for example, the rest obtained by the

  division of 56.5 / 10 was subtracted from the value 43

  in the memory M. The verification of the sign of the difference obtained by the subtraction indicated

  in this example the recognition of the negative sign.

  The recording bit h is therefore marked, and the negative difference is added to 100 so that the value 78 (43 - 65 + 100 = 78) is stored in the memory M. Whenever the last ordinary bit i

  must be marked, the contents of the memory M is checked.

  When the remainder is greater than the value stored in the memory M, the overflow of the card is recognized and, when the rest is equal to the value recorded, the exact depletion of the card is recognized, and the bit

  special j recording is marked.

  The special record bit j is not always necessary according to the invention. It is possible

  to recognize whether or not the card has been used by

  setting the status of the 9 ordinary record bits a to i and the value stored in the memory M. When the payment exceeds the maximum value assigned to the card, the buyer can execute the remainder of the payment in cash, or using another

  purchase card. An issuing body may predetermine

  undermine the maximum value of the card, for example 50 francs, francs, 1,000 francs, etc. The maximum value can be saved safely in the card by printing the value on the card or by forming holes through the card. In the previous embodiment, there is shown a previously loaded card, that is to say that the customer must first advance the sum

  corresponding. It can be considered that the invention applies

  also to a credit card with which the customer subsequently pays, to a memory card in which manufactured goods are stored, or bonuses corresponding to the purchases of the customers, and a scorecard in which scores of games

are saved.

  Although a record bit corresponds to 10 francs in the embodiment considered, it should of course be noted that a recording bit can

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  correspond to any natural number N. N being a divider

  of the division described above.

  The following materials can be used for the formation of the modifiable area of memory according to the invention: magnetic materials, opto-magnetic materials, thermally reversible materials or modifiable semiconductor memories, etc. On the other hand, the following materials can be used in the non-modifiable area of the memory according to the invention: the memories fixed by fusion, the memories to destruction

  of semiconductor devices, program memories

  electrically (including a protective cover

  against ultraviolet light), program memories

  electrically erasable (with electric lock preventing erasure). Physical recording methods can also be used for the non-modifiable area of memory, for example a method

  marking a hole in a card, a printing process

  of a material mark on a map, a process of irrational

  by a laser beam forming indentations on the surface of a thin metal layer having

  a low melting temperature, and a recording process

  recording of data on a hologram. Both recording areas can be in the same part

  a map (the assignment is suitable for a semi-

  driver) or can be separated (this assignment

  suitable for magnetic memory). The areas of registration

  are preferably positioned according to

  the convenience of writing and reading data.

  As previously described, the higher figures

  In the first recording area of a memory card, consisting of non-modifiable memories, the values of a value to be memorized are recorded according to the invention, and the lower digits of the value are recorded in the second recording zone constituted modifiable memories, so that the factors of safety and

  freedom be increased simultaneously.

  Of course, various modifications can be made by those skilled in the art to the processes which have just been described solely as examples.

  non-limiting without departing from the scope of the invention.

Claims (4)

  A method of recording data in a memory card in which a consumed amount of predetermined value is recorded, characterized in that the method comprises producing a first recording area on the memory card, said area having several recording bits (a to j) which are not modifiable when they have been marked, the realization of a second recording area on   the memory card, this zone having a modified device   reliable storage (M), dividing the quantity consumed by a predetermined natural number N to give a quotient and a remainder, recording the quotient in the first recording area in a non-modifiable way by marking the a number of bits   equal to the number of the quotient, and record it   the remainder in the second recording area in an editable manner, using the modifiable device memorisation.   2. Method according to claim 1, characterized in that a predetermined maximum value of the quantity   purchased is also stored in the memory card.   3. Method according to claim 1, characterized in that it further comprises the addition of the remainder to a value recorded in the second recording area so that a sum S is formed, the recording of the area S in the second recording area as a new value when the sum S is less than N, and the recording of the difference S - N in the second recording area as a new value and the marking of an additional bit of recording in the first recording area when S is greater than or equal to N. 4. Method according to claim 1, characterized in that it further comprises the subtraction of the remainder   of a value recorded in the second zone of record-   so that a difference T is obtained, the record   difference in the second zone of recording.   as a new value when T has a positive value and the recording of the sum T + N in the second recording area as a new value and the marking of an additional bit of recording in the first recording area when T has a negative value or zero.