NO122245B - - Google Patents

Description

Calculator for subscription television systems.

This invention relates generally to a calculator for use in a subscription television service; and more particularly it relates to a calculator for determining the necessary setting of the decoding mechanism in the subscriber receivers where this setting for any subscriber is different from the setting for the others,

and where the setting for one and the same subscriber is also different for each programme.

Subscription television systems have been proposed (where the program signal is coded at the transmitter according to a selected coding scheme, and where a key or coding signal indicating the coding scheme or coding scheme is transmitted to the subscribers' receivers as a modulation component of the television signal itself or over which preferably another channel.

For maximum secrecy, it is desirable that the transmitted code signal, which can be intercepted by anyone, should be derived from, but not a direct expression of, the coding method or coding scheme. Where this is the case, one can say that the transmitted code signal itself has been coded and therefore must

is read or interpreted before it can be used for decoding. The reading or interpretation of the code signal can be achieved with a switching mechanism which has a number of set-

only elements whose relative setting establishes a particular pattern of electrical connections and determines the decoder's response to the received code signal. It is

a distinctive switching mechanism for each subscriber's receiver, and therefore the switching position that allows a receiver to de-

code a given programme, be specifically different from the setting any other subscriber receiver might have for the same programme. One can therefore say that without knowing the exact setting for a subscriber's distinctive switching mechanism

ism, a correct decoding will be next to impossible. The necessary information about the connection setting can be transmitted to the subscribers in several different ways from a central station, e.g. orally over a telephone connection, or per mail, and its dispatch provides a specific target for the sender

tax to be determined for subscribers who have used the service.

Since the coupling setting is peculiar

for each subscriber, extensive calculations are included in the system's operation. The present invention solves this problem and provides a calculator for determining the individual information about the clutch setting quickly, accurately and easily.

Each subscriber's decoder is assigned a multi-digit identification number representing the distinguishing characteristics of its tunable switching mechanism. The-

t number is registered in the calculator and thereby circuits are established which absolutely and completely identify the distinguishing characteristics of the switching mechanism in this decoder. Another number that repre-

centers a selected subscriber program, is then registered in the calculator and correlation circuits react to the registered numbers and determine the exact setting necessary for this decoder to decode the selected program.

Accordingly, it is an object of the present invention to provide an improved calculator for subscriber's iron vision systems for determining the setting of the subscriber's decoding equipment to form a given decoding pattern.

Another object of the present invention is to provide a calculator which determines the setting of a decoding mechanism which has several working positions each of which establishes a predetermined code state.

A further object of the invention is to provide a calculator for determining the setting for a decoding mechanism which has a number of working positions which are set in correlation to a corresponding number of code states, in accordance with one selected pattern from a relatively large number of possible correlation patterns.

Yet another object is to provide a computing apparatus for determining the setting of a decoding mechanism assigned to a selected one of a relatively large number of subscribers, having a number of working positions each establishing a predetermined code state, and having a number of distinguishing characteristics that determine the correlation between the working positions and the code states.

It is also an object of the present invention to provide a calculator for determining the setting for each of a relatively large number of decoding mechanisms for each of several different subscription television programs, where each decoding mechanism is assigned to different subscribers and has a set of distinguishing characteristics which are particular to the subscriber to which it is assigned, so that the setting necessary for any given subscriber to be able to establish a predetermined code state in its assigned decoding mechanism is different from that necessary for the others subscribers must be able to establish the same code state, and where the setting is different for one and the same subscriber to establish different code states assigned to different programs.

A calculator according to the present invention is mainly characterized by the fact that it comprises program selection devices for delivering information that represents a specially selected code state for a predetermined one of the decoding mechanisms, decoder identification devices that deliver information that represents the correlation between working positions and code states in the decoding mechanism, and a decoder setting means which responds to the information from both of the aforementioned devices for determining the working position necessary for the decoding mechanism in question to establish the selected code state.

Otherwise, the new and characteristic features of the invention are specified in more detail in the patent claims. The invention and its further objects and advantages are explained in detail in the following description in connection with the accompanying drawings, where: Figure 1 is an explanatory schematic diagram of a coupling mechanism that can be used in the decoder on any of the receivers' in the aforementioned applications, and for which the calculator of the invention can determine the necessary setting information;

fig. IA and IB are function diagrams

for parts of the coupling mechanism in fig. 1;

fig. 2 is a simplified block diagram for a calculator made according to the invention;

Figures 3-24 together provide a detailed

production of the calculator in fig. 2; and

fig. 25 illustrates the way in which the drawings in figures 3-24 are to be arranged.

Before considering the detailed structure and operation of the calculator shown, it is desirable to discuss the special switching or decoding mechanism in fig. 1, which must be set by a subscriber in accordance with the information provided by the calculator.

In the switching mechanism, a combination of code signal wave trains or pulses, each of which has a predetermined identifying frequency, is transmitted to the subscribers' receivers together with the composite video signal in the field sampling interval. These pulses, which have a random sequence and appear randomly within each combination, are passed over a conductor 21f from the receiver's video amplifier and applied to a series of filter-rectifier units 21a-2le. Each such unit is highly selective for one of the tones or frequencies of which the code signal pulses are composed, and in this way the pulses are separated and rectified to be applied to the vertical rails of a transposition block 22f over a series of similar input circuits 22a— 22nd. This block is essentially an arrangement of intersecting rails and is provided with a pattern of electrical connections, shown as dots in the drawing, to input conductors 22a-22e which are interconnected in various ways, through a series of horizontal rails to a series of conductors 23a — 23rd. Electrical connections between vertical and horizontal rails can be conveniently achieved with conductive plugs. Block 22f provides a transposition at this location in the network and increases the system's secrecy.

All subscribers in the geographical area covered by the subscription service are arranged in 120 different groups, which corresponds to the largest number of different patterns of connections possible between a set of five conductors and another set of five conductors. Each subscriber's switching mechanism is provided with a transposition block 22f with a connection pattern in accordance with the particular group to which each subscriber belongs.

In the illustrative example of fig. 1, conductor 22a is connected to conductor 23a and then to the input of a movable code determining device or switch 13; conductor 22b is connected to conductor 23b and then to a code determining device 11; conductor 22c to conductor 23c and to the device 15; conductor 22d to conductor 23d and to device 14; while circuit 22e is connected to conductor 23e and to a code determining device 12. The devices 11-15 selectively establish, in a manner that will be described later, connections from conductors 23a-23e, and consequently from the input circuits 22a-22e, to a number of output circuits 1 "—7", which leads to different input terminals on a multi-stable impact device such as a bi-stable multivibrator.

With this arrangement, the code signal pulses are separated from each other on a frequency basis in the units 21-21e and applied to the mutistable influence device so that this device works between several stable operating states in a prescribed order determined by the position of the devices 11-15. The relative time difference between the video and synchronization components in the received subscription television signal is, in order to provide decoding, varied in accordance with variations in the operating state of the influencing device so that the operating state of the system changes synchronously with, but complementary to, the corresponding changes in the transmitter.

The details of the coupling mechanism.

The code-determining devices or switches 11—15 each have thirteen working positions and the construction of the switches is arranged so that in each position they make a connection from the input conductor to a selected one of the seven output conductors 1"—7". The extent to which the switch's movable part is displaced in relation to its many working positions is determined by a crossing point mechanism consisting of a pair of pivotably mounted arms which cooperate with a pair of cam wheels with 7 positions which determine the crossing point of the arms. This can be easily understood by looking at the functional diagram fig. IA.

The intersecting arms LI and L2 have a common axis of revolution P and each has a part Fl and F2 which follow the cams for engagement in an associated index cam disc 01 and 02. Each of the discs has seven sectors, depths or index faces, numbered from 1 to 7 , at different radial distances from the cam disks' axes of rotation Sl and S2. Sector 1 has the largest radial distance while sector 7 has the smallest. The others 2-6 have a constantly decreasing radial distance shown in subsequent steps in fig. IA, but can be arranged in irregular order to increase the secrecy of the system.

When the angular positions of the cam discs Cl and C2 are changed, the arms LI and L2 will rotate about the point P under the influence of the springs and the magnitude of the movement depends on the radial dimension of the active cam disc sectors in which the follower parts (hereafter the followers) Fl and F2 engage. For example with the sectors 1—1 gripped by the followers Fl and F2, the weight arms are in their most upright position and crossing or intersection point Å is at the greatest distance from the axis P. On the other hand, when the cam sectors 7—7 are active, the arms in their least upright position and the point of intersection X is as close to the axis P as possible. These two states or working positions define the range of movement of the intersection point X and the displacement range of the switch's movable element, because this element is held at the intersection point.

Seen from another point of view, the described mechanism can be compared to an integrator where the controlled element, the movable part of the switch, is in a position which depends on the sum of the radial distances for the active cam sectors Cl and C2. Where the cams are identical and have seven sections with progressively varying radial distances, the displacement range is from 2 to 14 times the displacement resulting from shifting from one section to the next section on any given cam. It is a range of thirteen steps, but this can be converted to an effective range of 7 steps with the connection shown in fig. IB.

The fixed contacts STI and ST2 on the switch are conductively connected to the input conductor IN. The movable contact is shown here as a bridge-like brush holder B which has brushes at each end and is mechanically connected to the crossing arms L1 and L2 in fig. IA as indicated by X. The length of the brush holder, the dimensions of the fixed contacts in the direction perpendicular to the conductors 1"—7", and the distance between these conductors and between the conductors and the fixed contacts are chosen in such a way that the brush holder B is the position shown, when the cam disc sectors 7—7 are gripped by the cam followers Fl and F2. For convenience, the output conductor that contacts the top brush is called 7", and for this position of the switch's movable element, input conductor IN is connected to output conductor 7". If one of the cams is moved so that its next sector is brought into active position, the brush holder B is raised or displaced one unit and makes contact with the next output conductor called conductor 6"; the next step of displacement brings the top brush into contact with output conductor 5" and so on. When the upper brush, during the gradual displacement of the holder. „■ through its area, moving away from

upper conductor 1", and makes contact with it: fixed contact STI, lower brush leaves the fixed' contact ST2 and makes contact with conductor 7". At the extreme end of the displacement range, when the cam sectors 1—1 are both active, the lower brush makes contact with conductor 2".

It is thus obvious that all the output conductors, with the exception of conductor 1", can be touched by either the upper or the lower brush on the holder B", while conductor 1" is only touched by the upper brush. This is called a "modulo 7" system where the position of the selector's movable element can be ascertained in the following way. The numbers indicating the active sections on both cams Cl and C2 are added, and if their sum is in the range a from 2 to 7 inclusive, the position of the switch's movable element is such that the input conductor is connected to the output conductor that has the same taliban designation. If their sum is greater than 8, the brush position corresponds to the difference between their sum and the number 7. When the sum equals 8, the movable element connects the input conductor to the output conductor 1".

In other words, Eir can say that the movable switching element has a displacement range or positions from and including 2 up to and including 14. These represent the only positions that the movable element can occupy and the correlation between these positions and the effective output conductor is shown in following table:

One now refers more specifically to fig. 1, each of the switches 11 to 15 has a mechanism of the type just described, but to simplify the drawing these mechanisms are indicated schematically. The cam discs that determine the position of the moving element in each switch have the same numerical designation as the switch itself, but with indices a and b, while the crossing arms that form the intersection mechanism are shown symbolically with dashed lines and again with the same numerical designation as the switch, but with an index c.

To facilitate selective setting of the many switches, these multi-section fcam discs are mounted on shafts. Shaft 16a holds discs 11b and 12a; shaft 17a holds discs 12b and 13a; shaft 18a holds the disks 13b Dg 14a; shaft 19a holds discs 14b and 15a, while shaft 20a carries a single disc 15b. Each of these shafts ends in a positioning knob, which for identification is provided with a corresponding reference number, and 5r rotatable in a clockwise direction, so that the shaft and the discs attached to it 3gso rotate, it has seven settings Named 1' -7'. Skive lia is mounted on an iorted axle and is not available to the subscriber. It is set at installation and can be adjusted from time to time by a service person to maintain and increase system secrecy.

The arrangement that has been described has the particular advantage that a particular pattern of conductive connections from the filter rectifier units 21a-21e to the output conductors 1" to 7" can be achieved with a number of different positions of the operating buttons 17<:>-20. This allows one to individualize the information that is necessary for each subscriber to be able to form a special pattern of connections. As an example, the following table shows the connections that are created through the switches to the output conductors under the influence of the crossing arms and cam disc pairs for the one in fig. 1 showed the position of the buttons:

The way the positions of the buttons. 16—20 are determined to establish a special pattern of connections from the filter rectifier units 21a—21e to the output conductors 1"—7" will in what follows be explained by describing how the calculator performs a typical calculation operation.

General discussion of the calculator.

In this discussion of the calculator, a general description will first be given with special reference to the block diagram in fig. 2. A keyboard 24 is arranged to register each of 7" or 117,649 different six-digit identification numbers, each of which is assigned to the switching mechanism of a particular subscriber. A selection of programs is also registered on the keyboard. The registered identification number indirectly represents the the particular cams or distinguishing features of a given subscriber's mechanism and also indirectly represent the transposition pattern of that subscriber's block. 22f. Such information is fed to a series of substitution switches 25-30 which transform the identification number into a representation in the form of a six-digit substitution number whose relation to the original -nently recorded identification numbers cannot be easily brought; in the pure. The replacement number is then fed to a series of auto-keys 31a—36a and 31b—36b, which respond to this and provide twelve elements of information representing the characteristics or peculiarities of the switching mechanism in the the decoder that responds to the registered identification number. Each autokey is affected in response to two of the digits in the six-digit replacement number so that these 2 digits are added and one information element is produced. With this arrangement, the individual digits in the replacement number are combined for addition in twelve different ways so as to produce representations of twelve different characteristics of the switching mechanism in the decoder assigned to the registered identification number.

Nine of the autokeys (31a-35a and 31b-34b.) are individually bubbled to specific memory switches 37-45 which are activated by these so that a memory unit is selected in each of the transposition blocks 46-54. The nine selected memory units each represent the particular configuration for a particular one of the nine index discs 12-15a and 11b-15b (Fig. 1). in the switching mechanism of the registered subscriber. The position of the fixed disk 11a is represented by the setting of a substitution switch 25 which is moved to a transpose block 55. The calculator has now been activated so that circuits are established which represent the particular index cams used in the switch mechanism of the decoder assigned to it. registered identification number.

Meanwhile, a program selection has also been registered using the keyboard 24. Each program preferably requires a different pattern of connections between the subscriber's input circuits 22a—22e and the output circuits 1"—7". Information regarding the exact connection pattern needed for each of a series of programs (for example, thirty different programs) is stored in a master code panel 66. When a program is selected, a selector or program selector 67 selects the stored information for the program using a code reader 68. In this way, the code reader indicates the switching pattern that must be established between the input and output circuits in the subscriber's switching mechanism in order to transmit the rectified pulses with frequency f,—f. to output keys 1"-7" according to the pattern determined by the stored information for the particular program selected.

The calculator must also clarify the particular transposition arrangement in the subscriber's decoder, and for this purpose the output of the auto-keys 36a, 35b and 36b represents which of the 120 different possible transpositions present in the registered mechanism. An input transposer 69 responds to the output of these three autokeys and in a way simulates the transposition pattern in block 22 f. The destinations or the different paths of the frequencies are represented by the output of the code reader 68 which is passed through the transposer 69, so that at its output an indication is formed of the connections of the input circuits 22a-22e to the switches 11-15.

It is expected that subscribers in a given geographical area will want to pay for the subscription programs as they are seen, instead of on a fee basis. For such subscribers, an additional transposer is inserted in series with block 22f so that every time a coin, e.g. 0.25 dollars, is added, different transpositions are established. The transposition that must be established in the coin-operated apparatus of these cash subscribers (as opposed to fee subscribers) for the selected program is represented by information supplied from the main code panel 66 and the code reader 68 through a binary decimal converter 77 to a cash transposer 76. The connections that must be established through such a transposition arrangement is created in the cash transposer 76 in response to this information so that the output from the input transposer 69 is partially transformed through the transposer 76. In order for a cash subscriber to be able to see a program, a certain number of coins, which together constitute the program's cost, is applied, this establishes a complementary transposition pattern which effectively cancels that introduced by transpose 76. For most subscribers, no cash transposition mechanism will be used and then transposer 76 will not indicate any transposition in addition to block 22f.

The output from the cash transposer 76 and part of the output from the input transposer 69 are fed to a series of binary-decimal converters 71-75 at the output of which an indication of the frequency of the rectified signal pulses supplied to each of the switches 11-15 for the subscriber in question is obtained about, and also an indication of which of the output circuits the rectified pulses must be supplied in order to successfully decode the selected program.

The code building process now takes place in the calculator. Considering that the setting of each individual control button, except button 20, changes the position of two switches, the desired button setting for establishing the desired circuits must be determined in order from right to left in fig. 1. A memory unit in transposition block 55 is selected to represent the active depth or section on the fixed disc 11a which partially controls the switch 11. This memory unit affects the addition unit 56 so that this depth is recorded. Information regarding the working position that the switch 11 must occupy is supplied to the addition unit from one of the converters 71-75 and the addition unit in reality selects the depth or section of the cam disc 11b which, when added to the depth or section of the cam discs lia, will set switch 11 to the desired output circuit. Information about the desired active depth of disk 11b is supplied through memory sector 37 to the selected memory unit in the transposition blocks 46 to determine the position of button 16 which places the required depth or section in engagement with the intersection mechanism lic. The desired setting for button 16 is indicated by an indicator light to inform the operator and subsequently also the subscriber.

Information about the position button 16 and consequently cam disc 12a must have is supplied from the selected memory unit in transposition blocks 46 to selector 38 and to the selected memory unit in transposition block 47 to indicate the active depth or section on disc 12a when button 16 is set in the desired position. This indication is used to influence the addition unit 57 to record this active depth on disc 12a which is to be used to determine the position of switch 12. Information about the position switch 12 must occupy is transferred to addition unit 57 from one of the converters 71-75 and the addition unit selects the depth or section that disk 12b must have, in order to get switch 12 in the desired position. Information regarding the desired depth is passed through selector 39 to the selected memory unit in transposition block 48 where the position of button 17 is determined, which will place this depth in the correct position. This desired setting is passed on to indicator lamp 62 to inform the operator and the subscriber of the setting needed for button 17. In the same way, the indicator lamps 63-65 are affected to indicate the respective positions of buttons 18-20.

A tape punch 82 is provided for keeping a register containing each registered identification number, the selected program and the price thereof.

Detailed consideration of the calculator.

The detailed construction of the calculator, shown in fig. 3-24, will now be processed. As mentioned, these figures must be arranged as shown in fig. 25 to form an overall form. The keyboard 24 in fig. 3 consists of 53 conventional push buttons, each of which actuates a normally open, single-pole, one-way switch. The movable contacts on all the switches are connected together and to the positive pole of a DC voltage source 24a. Each time a key is pressed, the moving contact on the corresponding switch causes the corresponding fixed contact to be applied to a positive potential. There are eight vertical columns of push-operated on-off switches, seven switches in the six vertical colonies on the left under the designation "subscriber identification number". The two columns on the right under the heading "Program" have six and five switches respectively. The push-operated switches for registering the subscriber's identification number are arranged in seven rows and each row represents a number between one and seven. As previously mentioned, each subscriber identification number contains six digits, and each digit can be any number in the range of one to seven. The seven rows are numbered from 1 to 7 in the drawing. Accordingly, when the identification number of any given subscriber is to be recorded, the operator presses one of the seven keys in the leftmost column corresponding to the first digit, presses down a key in the second column corresponding to the second digit, and so on. It should be noted that a selected pressure switch in each column is established (shown by dashed lines) in its "on" position. These will be dealt with later in connection with an illustrative example that will be considered

to explain the detailed workings of the whole

the calculator, so for the moment one ignores the switches that are closed.

One will also, when looking at figures 3-24, notice that certain conductors and contacts are drawn up with thicker lines than the others, either solid or dashed. One also ignores these thicker lines when describing the construction of the calculator, as they will be described later, when considering the active circuits in the illustrative example presented during the discussion of the mode of operation.

The six switches in the first column under "Program" are individually named A—F respectively and the five switches in the second column are named 1—5. The calculator, as illustrated, is capable of selecting the button settings for each subscriber for any of thirty different programs. To select the programme, one presses one of the push-buttons A—F and one of the switches 1—5.

The substitution switches 25— 30.

The fixed contacts on the switches which take care of the registration of the subscriber's identification number are connected to the substitution switches 25-30. The fixed contacts on the switches in the first column for recording the first identification digit are connected via conductors 48a—48g through a cable 48h to the row of seven fixed control contacts on the substitution switch 26. The fixed contacts in the second column for recording the second digit are connected via the conductors 53a—53g through a cable 53h to the seven fixed control contacts on the substitution switch 29. The fixed contacts in the third column for recording the third digit are connected via the conductors 51a—51g through a cable 51h. to the fixed control contacts on the substitution switch 27. The fixed contacts in the fourth column for recording the fourth digit are connected via conductors 41a— 41g through cable 41h to the seven fixed control contacts on the substitution switch 25. The fixed contacts in the fifth column for recording the fifth digit are connected via conductors 54a— Mg and through cable 54h to; the fixed control contacts on the substitution switch 30. Finally, the fixed contacts 1.sixth column for recording the sixth digit are connected via conductors 52a-52g and through cable .52h to the fixed control contacts on the substitution switch 28. The circuits which the program selection switches in the keyboard 24 are to be connected with will be explained later.

Each substitution switch 25-30 consists of a conventional, seven-point, rotary step switch, which, when a positive potential is applied to one of its seven fixed control contacts, reacts by gradually moving a group of contact arms over to said contact and holds them there until the coupler is returned to the rest position. Each substitution switch also has several levels of fixed contacts (seven contacts per level) and the contact arm group has a corresponding number of contact arms that work together so that a contact arm establishes an electrical connection to a selected fixed contact on each level, and this selected contact is determined by which fixed control contact there is a positive potential. The seven fixed contacts on the first level of the switch 25 are connected via conductors 43a—43g which form cable 43h to the contact arms on the second to eighth levels of the substitution switch 26. The fixed contacts on the first level of the switch 26 are connected via conductors 42a—42g which form cable 42h to the second to eighth level contact arms of the substitution switch 25. The first level contact arm 25a of the switch 25 and first level contact arms 26a of the switch 26 are connected to the positive pole of the respective voltage sources 25b and 26b.

The forty-nine fixed contacts on the second to eighth levels of the switch 25 are connected in seven groups of seven contacts in each in a random manner, and each of the seven groups is connected to one of the conductors 44a—44g which are then further connected through a cable 44h to the fixed steering contacts on car key 31a. Similarly, the forty-nine fixed contacts on the second to eighth levels of the switch 26 are connected with seven contacts in each according to a random pattern, and the conductors 49a-49g connect each of the seven groups through a cable 49h to the fixed control contacts of the car key 32a .

With this arrangement, the registration of the first and fourth digits of the subscriber's identification number by manipulating

operation of the keyboard 24 energizes selected contacts on the substitution switches -25 and 26. Accordingly, when the switch brushes scan the contact sets, the contact arms will stop at a vertical column determined by the fixed contacts imprinted "penning, indicated by dashed continuations of the contact arms in fig. 5, this will be explained later.

After the switches 25 and 26 have taken up selected positions in this way, the potential from source 25b, which is applied to trailing contact 25a, is transferred via one of the conductors 43a-43g which is connected to the contact arm touches, through cable 43h, to the associated arm of switch 26 and then over one of the conductors 49a—-49g, which is connected to the contact arm touches, and to

the specific contact on car key 32a.

This provides a control voltage on the car key

32a. In a similar manner, the potential from the source 26b applied to the contact arm 26a is transferred to one of the conductors 42a-42g which is connected to the contact arm.

on, then via cable 42h to the corresponding arm of the switch 25, and over it determined by the conductors 44a—44g to a selected fixed control contact on car key 31a. Due to the random nature of the connections between the fixed contacts of switches 25 and 26, the recording of

■first and fourth digits result in a representation on the autokeys 31a and 32a whose relation to the real registered digits cannot be easily established.

The fixed contacts on the ninth level in the switch 25 are connected via conductors 45a-45g and through a cable 45h to the horizontal rails in transposition block 55 in fig. 19. Contact arm 25c on the ninth level is connected to the positive pole of a voltage source 25d and after the switch 25 has taken a selected working position, a positive potential from the source 25d is applied to one of the fixed contacts on the ninth level and then supplied a horizontal rail in block 55 for reasons that will be explained later. The tenth level fixed contacts in the switch 25 are connected via the conductors 46a-46g and through a cable 46h to the horizontal rails of a corutkt panel 77j which is in the input circuit of the binary-decimal converter 11 (Fig. 23). Contact arm 25e on the tenth level of the switch 25 is connected to the positive pole of the voltage source .251 and after it has been moved step by step to a selected working position, a voltage from the source 25f is impressed on one of the conductors 46a-46g and led to a selected horizontal rail on contact panel 77j, this

also for reasons that will be dealt with later.

The eleventh level contacts of the switch 25 are connected over conductors 47a-47g and through a cable 47h to a larger cable 70 which is then connected to a decimal-binary converter 121 (Fig. 22). Contact arm 25g on the eleventh level is connected to the positive pole of the voltage source 25j so that this potential is applied to the selected, fixed contact on the eleventh level which the contact arm touches and from there to one of the conductors 47a— 47g.

The ninth level fixed contacts of the substitution switch 26 are connected via conductors 50a-50g and through a cable 50h, and a larger cable 70, to a decimal-to-binary converter 122 (Fig. 22). Contact arm 26a for this switch level is connected to the positive pole of a voltage source 26b and moves one of the fixed contacts this potential when the switch 26 has taken one of its working positions and thereby applies a control voltage to the corresponding one of the conductors 50a-50g .

Substitution switches 27 and 28 are connected in much the same way as switches 25 and 26, but they respond to the registration of other digits in the subscriber's registration number; and more specifically, the third digit controls the position of the switch 27 and the sixth digit the position of the switch 28. The fixed contacts on the first level of the switch 27 are via conductors 62a— 62g located in cable 62h connected to the contact arms on the second to eighth levels of the switch 28. The fixed contacts on the first level of the switch 28 are connected via conductors 61a-61g forming cable 61h to the contact arms on the second to eighth levels of the switch 27. Contact arm 27a on the first level of the switch 27 is connected to the positive pole of the voltage source 27b. Similarly, contact arm 28a on the first level of the switch 28 is connected to the positive pole of a voltage source 28b. The forty-nine fixed contacts on the second to eighth levels of the switch 27 are connected in seven groups of seven contacts in each in a random manner and each group is connected to one of the conductors 63a—63g and through a cable 63h to the fixed control contacts on the car key 33a. The forty-nine fixed contacts on the second through eighth levels of the switch 28 are likewise connected together in seven groups of seven contacts in each. Each of the seven groups is connected to a specific one of the conductors 65a-65g and through a cable 65h to the fixed control contacts on the car key 34a.

In response to the registration of the third and sixth digits of the subscriber identification number, a potential is impressed on a selected one of conductors 51a-51g and also one of conductors 52a-52g. Consequently, the contact arms on the switches 27 and 28 will be moved step by step to the selected contact positions, and positive potential from source 27b is applied to contact arm 27a and is led through the conductors 62a—62g to an associated contact arm on the switch 28 and from there over one of the conductors 65a— 65g to a fixed steering contact on car key 34a. In the same way, a positive voltage from the source 28b is applied to the contact arm 28a and led through a selected one of the conductors 61a-61g to a contact arm on the switch 27 and from there via a selected one of the conductors 63-63g to one of the fixed control contacts on the car key 33a.

The ninth-level fixed contacts of the switch 27 are connected via conductors 64a-64g to a cable 64h which is then connected through a larger cable 70 to a decimal-to-binary converter 123. The ninth-level contact arm 27c of the switch 27 is connected to the positive pole of a voltage source 27d and applies this potential to one of the conductors 64a-64g after the contact arm of the substitution switch has been moved incrementally to one of its working positions. Similarly, the ninth level fixed contacts of switch 28 are connected via conductors 66a-66g to a cable 66h and over a larger cable 70 to a decimal-to-binary converter 124. Ninth level contact arm 28c is connected to the positive terminal of a voltage source 28d and after the switch 28 has assumed a selected working position, this potential is applied to a selected one of conductors 66a—66g and led to converter 124.

The switches 29 and 30 are also connected in the same way as the previously treated substitution switches, but in this case the position of the switch 29 is controlled by the second digit in the subscriber's identification number and the position that the switch 30 is set to is determined by the fifth digit in this number. The fixed contacts on the first level of the switch 29 are connected via conductors 58a-58g which form cable 58h to the contact arms on the second to eighth levels now on the switch 30. The fixed contacts on

first level now switches 30 are connected via conductors 57a—57g which form cable 57h to

the second to eighth level contact arms

now switch 29. Contact arm 29a now first level of switch 29 is connected to the positive pole of voltage source 29b. Contact-

arm 30a of the first mva pa dies is connected to the positive pole of a voltage source 30 b.

The forty-nine fixed contacts on the second to eighth levels of the switch 29 are connected in a random manner to form seven groups of seven contacts in each, conductors 59a—59g are connected to the respective groups for transmitting information over a cable 59h to the fixed control contacts on car key 35a. The forty-nine second through eighth level fixed contacts of switch 30 are also connected in groups of seven in a random fashion, with each group connected to one of the conductors 67a-67g and then over a cable 57h to the fixed control contacts of auto key 36a . After a potential has been applied to a selected one of the fixed control contacts on the switch 29 from the keyboard in response to the registration of another digit in the subscriber's number, the contact arms on the switch 29 are moved step by step to the selected position corresponding to the control contact where there is a potential. Likewise, after a potential has been applied to one of the fixed control contacts on the first level of switch 30 in response to the registration of the fifth digit in the subscriber's number, substitution switch 30 is moved to the working position corresponding to the control contact on which there is voltage. A positive voltage from the source 29b is thus carried over contact arm 29a and a selected one of the conductors 58a-58g to one of the contact arms on switch 30 and then over one of the conductors 67a-67g to one of the fixed control contacts on car key 36a. A positive voltage from the source 30b is similarly led over contact arm 30a and a selected one of the conductors 57a—57g to one of the contact arms of switch 29 and then over a selected one of the conductors 59a—59g to a fixed control contact on auto-key 35a.

The ninth-level fixed contacts of switch 29 are connected via conductors 60a-60g to a cable 60h which is then connected through a larger cable 70 to a decimal-to-binary converter 125. Ninth-level contact arm 29c of switch 29 is connected to the positive pole on the voltage source 29d in order for a voltage to be applied to a selected one of the conductors 60a-60g after switch 29 has been moved over to one of its working positions. Likewise, the ninth level fixed contacts of switch 30 are connected across conductors 68a-68g to cable 68h and then through a larger cable 70 to a decimal-to-binary converter 126. Ninth level contact arm 30c of switch

"JU is KOOiet Ul aen posiuve yui ya ojjen-ningelden 30d for a voltage to be applied to one of the conductors 68a-68d after switch 30 has assumed one of its working positions.

Transmission of information through cable 70 from each of the six substitution switches to the converters 121-126 is used to keep a register of each time a subscriber's identification number is registered on the keyboard 24. This will be described in more detail later.

Car keys 31— 36.

With the equipment described so far, the subscriber's identification number is registered on the keyboard and a representation of this number, which is found on

cable 41h, 48h, 51h, 52h, 53h and 54h, stays on most steering contacts on the car keys

changed or transformed into an unrecognizable representation 31a—36a as it is almost

impossible to decipher. If such a conversion were not carried out, there would be a definite correlation between the digits in each identification number and the configuration of the cam discs. It would then be a relatively simple matter for a cryptographer to determine the shape of the various cams in the subscriber's switching mechanism

has, by examining the subscriber's identification number.

Like the substitution switches, the autokeys are conventional seven-stage rotary tap switches each having a number of contact arms, each assigned a predetermined level, and which together move stepwise over fixed contacts to occupy a predetermined position of which contact is applied voltage. The auto keys work in pairs, and the two in a pair have the same numerical reference, but with different indices a and b. The twelve auto keys which thus work in pairs, in reality make up six step switches with fourteen contact levels in each. Both car keys in a pair, such as 31a and 31b, takes the same working position and this position is determined by the special manager to the first level on one of the two auto keys where a positive potential is applied. For the illustrative pair 31a—31b, the manager in the group 44a—44g is impressed with sDenning and determines the working position

for both parts of the pair. Likewise, for the pairs 32a—32 b, 33a—33b, 34a—34b, 35a—35b

and 36a—36b are the respective board-chairman designations that determine the work position 49a—49g, 63a—63g, 59a—59g and 67a—67g.

Conductors 44a-44g which are connected to the fixed control contacts on car key 31a are also connected through cable 44h to the seven contact arms belonging to the car keys 36a and to the seven contact arms on car key 35b. Conductors 49a—49g are connected to the fixed control contacts on car key 32a, and also to the contact arms on car key 31a and via cable 49h to the seven contact arms on car key 36b. Conductors 63a-63g which lead to the control contacts of car key 33a are also connected to the seven contact arms of car key 32a and to the seven contact arms of car key 31b. Conductors 65a— 65g which are connected to the fixed control contacts on auto key 34a are also connected to the seven contact arms on auto key 33a and via cable 65h to the seven contact arms on auto key 32b. Conductors 59a—59g are connected to the fixed control contacts on car key 35a, are also connected via cable 59h, to the seven contact arms on car key 34a and also to the seven contact arms on car key 33b. And finally, the conductors 67a—67g are connected to the fixed control contacts of auto key 36a and also to the seven contact arms of 67h to the seven contact arms of auto key 34b.

The seventh level fixed contacts of auto key 31a are connected via conductors 69a-69g and through a cable 69h to the fixed control contacts of memory selector or selector 37. The last level fixed contacts of auto key 31b, which is actually the fourteenth level of the auto key combination 31a and 31b, is connected via conductors 70a—70g and through a cable 70h to the fixed control contacts of switch 38. The fixed contacts on the last level of auto key 32a, is connected via conductors 71a—71g and through a cable 71h to the fixed control contacts on selector 39. The fixed contacts on the fourteenth level of the auto-key combination 32a and 32b, which are the last nine-eight on auto-key 32b, are connected via conductors 72a-72g and through a cable 72h to the fixed control contacts on memory selector 40 The fixed contacts on the last level of auto key 33a are connected via conductors 73a—73g and via cable 73h to the fixed control contacts on selector 41. The fixed contacts on the last level of auto key 33b are connected via conductor e 74a—74g and through cable 74h to the fixed control contacts on selector 42. The fixed contacts on the seventh level of auto key 34 are connected via conductors 75a—75g and through a cable 75h to the fixed control contacts on selector 43. The fixed contacts on last level of auto key 34b is connected via conductors 76a-76g and through a cable 76h to the fixed control contacts on selector 44. The fixed contacts on the last level of auto key 35 are connected via conductors 77a-77g and through cable 77h to the fixed control contacts on selector 45. The fourteenth level fixed contacts of the autokey combination 35a and 35b are connected via conductors 78a-78g and via a cable 78h to the fixed control contacts of a conventional seven-step rotary tap changer 140 which is part of the input transposer 69. The fixed contacts on the last level of auto key 36a are connected via conductors 79a—79g through a cable 79h to the fixed control contacts of a conventional, seven-stage, rotary step switch 141 which also belongs to the Input Transpone reren 69. The fixed contacts on the last level of auto key 36b are connected via conductors 80a-80g and via a cable 80h and the fixed contacts on yet another rotary step switch 142 which is included in the input transposer 69.

The auto keys are similar in construction and may be considered an electrical counterpart to the integrator or adder discussed in the discussion of FIG. IA and IB, added to a "modulo 7" system. In other words, if the fixed control contacts of any auto key are numbered 1-7 and the contact arms of its different levels are similarly numbered 1-7, then the connections between the level's contacts are arranged so that voltage applied to a fixed contact, assigned a determined number, and the simultaneous application of voltage to a contact arm, also assigned a determined number, produces a potential on the output terminal (level number 7) of the auto key which has a numerical designation corresponding to the sum of the two determined numbers when the sum is 7 or less, and corresponding to the difference between their sum and 7 when the sum is greater than 7.

To explain this, one can assume that the fixed contacts on auto key 31a are , given the numerical designation 1-7 counted from the left, while the contact arms have the numerical designation 1-7 counted from the arm that is connected to conductor 49a and down to the arm that is connected to 49g. Furthermore, it is assumed that the output terminals to which conductors 69a-69g are connected have numerical designations 1-7 counted from left to right. If voltage is applied to control contact number 3 and contact arm number 2, a voltage will appear on the output terminal to which conductor 69e is connected, i.e. fifth terminal. How the voltage appears on the particular terminal can be made clear as follows: When voltage is applied to control contact no. 3, the contact arms will scan the contacts and stop at contact column no. 3. Since contact arm no. 2 itself is applied voltage, a voltage will be carried from the contact it touches and through a conductive zigzag connection over several contact levels to output contact 69e.

The twelve autokeys are used to produce twelve elements of information that identify the variables in the subscriber's decoding mechanism. As previously explained, the recording of the six-digit identification number assigned to each decoder will establish working positions in the substitution switches 25-30 so that a new number having no obvious relationship to the identification number, although there is a precise relationship between them determined by the transposition agents introduced by the substitution switches. This six-digit substitution number supplies, via the described cable connections from the substitution switches, the six autokey pairs, each member of each pair with two digits. These digits are added in the autokey to which they are supplied and their addition results in a further twelve numbers or information elements which also, as they are produced according to a pattern created from the registered identification number, stand in a definite and precise relation to the subscriber's switching mechanism such as the calculator shall determine decoding information for. Nine of these information elements from the group of twelve are supplied via the described connections to memory selectors 37-45 and the remaining three are supplied to step switches 140-142 in the input transponder 69.

The nine information elements are supplied to the memory selectors 37-45 and each represent a specific one of the nine cam disks 12a-15a and 11b-15b which are part of the decoding mechanism in fig. 1. Another information element, which alludes to the active section of the fixed disc 11a in this mechanism, is supplied to transposition block 55 from the ninth level of substitution switch 25 via cable 45h. This is so because the fourth digit of the subscriber identification number indicates the setting of this dial and also determines the information produced at this switch level. The three pieces of information supplied to the input transposer 69 from the auto keys together represent the particular one of the 120 possible different transpositions that can be obtained by means of a device represented by block 22f in the subscriber's mechanism.

The memory selectors or - selectors 37— 45.

The selectors 37-45 are conventional seven-step rotary tap switches and are very similar to the substitution switches. There are seven levels on each selector and seven contact arms, one for each level, arranged so that they can be moved incrementally over

contacts. Each of the seven columns with

fixed contacts on selector 37 are connected to a group of vertical rails on a particular one of seven transpose blocks or memory units comprising element 46. Each of the seven transpose blocks has a series of randomly placed connections from the vertical to the horizontal rails, shown as dots in the drawing . Each horizontal rail corresponds to a specific one of the seven possible angular positions for the index disc 11b as indicated by the numbers 1-7'. Moreover, each of the vertical rails in each individual memory unit corresponds to a specific one of the sections on disc 11b. As shown, selector 37 is capable of selecting any of seven different memory units or blocks and thus any of seven differently shaped disks that can be used as disk 11b. "Differently shaped" is used here to imply

the order that the seven cam selectors have on the dial. The horizontal rails

on the blocks 46 are connected together and over conductors 95a—95g to the indicator lamp 61 which

shows the desired setting for button 16. Lamp 61 may be of conventional construction and responds to a voltage applied to any of its seven inputs so that a corresponding number from one to seven is illuminated. Conductors 95a—95g are also connected through a cable 95h and a series of rectifiers, which are inserted for isolation, to the contact arms of selector 38.

The scanning of the contact arms in selector 37 is interrupted when the arms make contact with a contact which has voltage due to the fact that there is voltage on one of the conductors 69a—69g,

determined by output from car key 31a. IN

their selected positions, the contact arms are connected to the vertical rails of a particular one of the transposition blocks or memory units. The selected block suggests the particular shape of the disc 11b

in the switch mechanism corresponding to it

registered identification number and for which the calculator will calculate information. The designation for a special intersection point in the selected block, which specifies a certain sector on this cam disc, will be explained immediately.

Transposition blocks 47-54 are the counterpart of blocks 46. However, in the case of blocks 47, 49, 51 and 53, the horizontal rails represent the depths or comb sectors of the respective discs 12, 13a, 14a and 15a, while the vertical rails represent the angular positions for the same slices. The blocks 48, 50, 52 and 54 represent the respective disks 12b, 13b, 14b and 15b. The memory selectors 37-45 are activated according to information supplied from certain of the autokeys for selecting the special memory units that specify the shape of the cams in the subscriber's tram positioning mechanism. They also respond to other influences, which will be described later, to specify the particular depths or sectors for these slices to decode a given program.

The addition units 57— 60 and their effect on the selectors 37— 45.

Transposition block 55 comprises another arrangement of intersecting rails with seven vertical rails each representing one of the depths or comb sectors of the fixed index dial 1a on the subscriber's decoder, the block also has seven horizontal rails each connected to one of conductors 45a-45g which leads from substitution switch 25. Connections are made from different places in a random pattern between the vertical and horizontal rails. A voltage appears on one of the conductors 45a-45g in accordance with the fourth digit of the subscriber's identification number. This tension is transferred from the horizontal rail on which it is impressed, to one of the vertical rails determined by the special cross connection included in this horizontal rail. The vertical rails are connected to seven fixed control contacts of a "modulo 7" adder 56 comprising a conventional seven-stage rotary tap changer. This addition unit is very similar to the auto-keys 31a. Its fixed guide contacts are numbered 1-7 to denote the different depths or sectors of the cam disc.

Adder unit 56 has seven contact levels and a contact arm for each level. These contact arms are connected via conductors 112a—112g to the seven input conductors of a binary/decimal converter 71 (fig. 24). These output conductors correspond to the output conductors from switch 11 and are accordingly designated 1" to 7". To achieve decoding, switch 11 must make contact with a special output conductor and the corresponding conductor from converter 71 is activated so that it applies a voltage to the contact arm of addition unit 56. This connects the contact arms of the adder 56 and the output conductors of the switch 11 as shown by the numbers 1"—7" by the contact arms in the drawing

The fixed contacts on the addition unit 56 are connected in the same way as on the auto keys. When the contact arms are therefore moved step by step to scan their contacts, they stop when they reach the contact that is energized. This contact identifies the active sector on the cam disk. At the same time, converter 71 identifies the output conductor that switch 11 is to be connected to by applying a voltage to a contact arm on the adding unit. A calculation operation is then automatically performed due to the coupling in the adder unit 56, which determines the particular depth or sector of cam disc 11b which must be activated to set switch 11 to make contact with the particular output conductor. The output terminals of the adding unit 56 therefore represent the different depths or sectors 1-7 on the cam disc 11b, for the sake of convenience the numbers 1-7 are applied to the drawing.

These output terminals are connected via conductors 96a-96g through a cable 69h to the movable contact arms of the selector 37. A voltage is transferred from the output terminal which has voltage and to the determined by the contact arms of the selector 37 which have already been moved to a selected one of their vertical contact columns and selects a memory unit representing the configuration of cam 11b in the subscriber's switching mechanism. The voltage on the contact arm of selector 37 indicates the depth or sector of cam 11b required and is then transmitted along one of the vertical rails of the transposition block connected to the selected vertical column of fixed contacts in selector 37 to determine the angular position of disc 11b which places the required cam sector in engagement with the intersection mechanism lie which controls switch 11. The desired position of cam disc 11b is determined by the intersection between a vertical rail in selector 37 and one of the conductors 95a-95g. Indicator 61 then displays a selection of the numbers 1'-—7' which represent the desired setting for button 16.

The information determined in this way, regarding the position of disc 11b, is then fed via cable 95h to the contact arms of selector 38 to determine the particular active depth or sector of cam disc 12a which is the result of this position of disc 11b since both are fixed on the same axle 16a. Thus, a voltage from a contact arm on selector 38 will appear on one of the vertical rails in one of the memory units in element 47 and be transferred via a crossing contact to a corresponding horizontal rail representing the active depth on disk 12a.

The horizontal rails of the transposition blocks 47 are connected via the conductors 97a-97g and through a cable 97h to the fixed control contacts of a seven-stage adding unit 57. This adding unit is the counterpart of the adding unit 56. A selected one of its fixed control contacts is applied voltage in accordance with previous determination of the active sector of cam disc 12a in transposition blocks 47. This disc, in conjunction with cam disc 12b and intersection point mechanism 12c, sets switch 12 with respect to output conductors 1"-7". The special output conductor that switch 12 must contact is represented by a correspondingly named output conductor from the henar/decimal converter, this conductor then puts voltage on a specific one of the contact arms on addition unit 57, as it is connected to this with cable 113h. The contact arms of the adding unit stop the scanning at the vertical column corresponding to the fixed control contact with voltage, and with the help of the contact connections between the levels of the adding unit, a special output terminal is applied with voltage. This terminal's numerical designation corresponds to the depth or sector of cam disc 12b that must be activated to cooperate with the predetermined setting of cam disc 12a for setting switch 12. A cable 99h connects the output terminal of addition unit 57 to the contact arms of selector 39.

The contact arms of the selector 39 are moved incrementally over the contact levels until it makes contact with the fixed control contact which has voltage supplied from the auto key 32a via a selected conductor of the series 71a-71g. This interruption of the scan identifies the special transposition block 48 which identifies the shape of the cam disc 12b in the decoder in question. On the selector, the contact arm, which is supplied with voltage through the adding unit 57, picks out a specific one of the vertical rails on the selected transposition block 48, and thus identifies by numbers the cam section or depth to be used. The contact at the intersection between the vertical rail and a horizontal rail within this transposition block converts the imprinted information elements into a determination of the angular position of switch 12b which will set it so that it makes contact with the desired output conductor. This determination is shown by a correspondingly identified indicator lamp 62 lighting up. The number that is illuminated corresponds to the setting that control button 17 should have.

The other selectors and adder units work in much the same way to determine the necessary settings for the other operating buttons to achieve the correct connections between the input circuits 22a-22e and the output conductors 1"-7" in the subscriber's decoder.

The conductors 98a—98g from selector 39 are connected via a cable 98h and through a series of insulating decoders to the contact arms of selector 40. The horizontal rails in transposition blocks 149 are connected via conductors 101a—101g and through a cable 101h to the fixed control contacts of adding unit 58 for setting its contact arms in accordance with the special sector on disc 13a which is active when button 17 is in the desired position. Information from converter 73 is received over conductors 114a—114g which are connected to the contact arms of addition unit 58. This information specifies the output conductor switch 13 is to contact. The output terminals of the adding unit 58 are connected via a series of conductors 103a—103g and through a cable 103h to the contact arms of the selector 41. This searches out the memory unit that represents the shape of the cam disk 13b in the subscriber's decoder; and then, in response to a voltage applied to one of its contact arms from adding unit 58, determines the desired sector on cam disc 13b and finds the angular position of disc 13b which places this sector in such a position that it cooperates with the active sector on disc 13a for setting switch 13.

The horizontal rails on transposition blocks 50 are connected via conductors 102a-102g to indicator lamp 63 for displaying the setting of button 18 which the subscriber must make. Conductors 102a-102g are also connected via a cable 102h and through a series of isolation diodes to the contact arms of selector 42 to find the particular depth of disc 14a which is placed in engagement with mechanism 14c of switch 14 when button 18 is set as indicated of lamp 63.

The horizontal rails of transposition blocks 51 are connected via conductors 104a

— 104g and through a cable 104h to the fixed control contacts on adding unit 59 to indicate the active depth of cam disc 14a. The contact arms of adder 59 are connected to conductors 115-115g to receive information from converter 74 indicating which output conductor selector 14 is to pick. The addition unit 59 uses both information elements to calculate the depth or sector of disk 14b that must be used to achieve the correct setting of switch 14. Conductors 106a—106g connect the output terminals of addition unit 59 through cable 106h to the contact arms of selector 43 to find the position button 19 must have to get the correct index surface or depth on disc 14b in position. The horizontal rails on transposition blocks 52 are connected via conductors 105a——105g to indicator lamp 64 which, by lighting up a number from 1 to 7, indicates the position button 19 must be given by the subscriber. Conductors 105a-105g are also connected via cable 105a and through a series of isolation diodes to the contact arms of selector 44. Selector 44 carries information about the setting of button 19 to the selected memory unit in blocks 53 to find the particular depth of dial 15a that is engaged with the intersection mechanism 15a when button 19 is set.

The horizontal rails of transposition blocks 53 are connected via conductors 107a-107g and through cable 107h to the fixed control contacts of addition unit 60 to obtain information about the active depth of disk 15a. Adder unit 60 receives information from converter 75 via conductors 116a

—116g if the output conductor switches 15 must contact. The adding unit reacts to this information and also to the information representing the active depth of disc 15a, and provides on its output terminals a representation of the sector of cam disc 15b which must be used to set switch 15 correctly. The output terminals of adding unit 60 are connected via conductors 108a-108g and through cable 108h to the contact arms of selector 45. These contact arms are, by means of information from auto key 35a, set on a vertical contact column for connection to one of the memory units or blocks in element 54 which represent the shape of cam disc 15b. A potential on one of the contact

AU

the arms of selector 45 indicate the sector of cam disc 15b that must be placed in engagement with mechanism 15c, this depth is found in the memory unit which indicates, via one of the horizontal rails on blocks 54, the position button 20 must have. These horizontal rails are connected via conductors 109a-109g to indicator lamp 59 which shows the operator the desired setting for button 20.

We will now look at how the information that denotes the setting of switches 11—15 in relation to the output conductors 1"—7" for a selected subscriber program is fed to the contact arms of the adding units 57—60. The described calculator is capable of performing the necessary calculation work for any of thirty different programs and the result of the calculations, namely information to be distributed to the subscribers, is different for each of them. For each program, certain information must be determined in advance, namely the particular destination or path for each of the five frequencies f,-f-used for transmitting code information and found on the input circuits 22a-22e of the subscriber's decoder, in relation to the output circuits 1"—7". In addition, for those subscribers who are called cash subscribers, information on the cost of each program must be selected. All this information is found in the calculator in the storage device and is at hand when you need it in the calculations. The storage device is the main code panel in fig. 4.

Main code panel 66.

In the illustration, the main code panel 66 has thirty contact columns with nineteen contacts in each column. Each column stores information for a specific one of the thirty programs and is labeled Al—F5 for convenience. A continuous vertical rail belongs to each column and these rails are connected together and to the positive pole of DC voltage source 66j. Voltage can be applied to any of the different contacts in each column by means of connections from the contacts to the vertical rail.

The four southernmost contacts in each column, counted from top to bottom, are devoted to price information and as they can be connected to the vertical rail in sixteen combinations, they allow sixteen different price categories. However, for simplicity, one uses only nine different combinations, representing nine different prices. The other contacts in each column are divided into five groups of three in each and each of these groups represents the path a particular one of the code frequencies f,—f- is to take, as indicated on the right side of panel 66. Since there are seven output conductors 1 —7 concerned with the path or route of the code frequency, seven connection patterns are used, and the pattern selected for any particular 3-pin group indicates to which of seven output circuits 1"—7" one of the switches 11— 15 must be connected in order for the code frequency group it represents to be routed via the correct route.

What represents the price and frequency routes is in binary form so that the necessary number of connections is as small as possible. From the random way in which the connections between the contacts and the different vertical rails are made, one sees that a large selection of different code and price combinations are used for the thirty different programs. A code reader 68 reads the circuit connections that have been created in a selected one of the thirty columns on the main panel during the calculation process.

Code reader 68.

Code reader 68 also consists of a conventional, rotary step switch with thirty positions, each of which is associated with a specific column on panel 66, and thereby with a special program. There are nineteen different contact levels and a contact arm for each. The contacts on each level are connected through a cable 81 to the contacts on a corresponding row of contacts on the contact panel 66. In this way, each of the contacts on the contact panel 66 is connected to a corresponding contact on the code reader 68. If a voltage appears on a contact on the contact panel 66, then the same voltage will appear on the corresponding contact in the code reader. The connections made in panel 66 for a particular program are read when the contact arms of code reader 68 are moved step by step to the contact column belonging to that program.

Program selector 67.

Program selector 67 is arranged to bring code reader 68 to any such column of fixed contacts. It is a rotary step selector with six working positions and five contact arms. The six fixed control contacts are connected via conductors 56a—56f to the push switches A—F on the keyboard 24 and the five contact arms are connected via conductors 55a—55e and to the five push switches 1—5 in the "program" section of the keyboard 24. Each of the other thirty fixed main control contacts i selector 67 is connected to a specific one of the fixed control contacts on code reader 68.

Described in more detail, the fixed contacts in the first column of selector 67 are connected via conductors 85a-85e, through cable 85h, to the first five control contacts of reader 68; these contacts belong to programs named Al—A5. Another column of fixed contacts on selector 67 is connected via conductors 86a-86e, through cable 86h, to the next set of five control contacts on the reader dedicated to the program denoted Bl-B5. The third column of fixed control contacts on selector 67 is connected via conductors 87a—87e, through cable 87h, to the five control contacts on reader 68 belonging to programs 01—05. The next set of fixed contacts on selector 67 is connected via conductors 88a—88e, through cable 88h, to the control contacts on reader 68 that belong to programs D1—D5. The fifth column of contacts on selector 67 is connected via conductors 89a—89e, through cable 89h, to the control contacts on reader 68 belonging to programs E1—E5. The last column of contacts on selector 67 is connected via conductors 90a-90e, through cable 90h, to the first set of five control contacts on reader 68 and these contacts are devoted to the programs designated Fl-F5.

Every time one of the keys A—F on the keyboard 24 is pressed, a voltage will appear on the one of the control contacts on the program selector 67 to which that key is connected so that the scanning of the contact arms on the selector stops when they reach this particular contact. In addition, when one of the program keys 1-5 on the keyboard is pressed, a voltage will appear on the corresponding

of the contact arms on the selector 67, this voltage is passed on to the code reader's 68 fixed

control contacts that correspond to the special program one has selected on the keyboard 24.

The necessary information regarding the selected program, which indicates the rates and the weights of the code frequencies f,-f5 to be carried, is available in the form of a selective application of voltage to the contact arms of code reader 68 that touch voltage-carrying contacts in the contact column of the reader assigned to the selected program. Before making a calculation on the basis of this information, it is necessary to take into account that each subscriber's decoder contains a transposition block 22f as shown in fig. 1. This transposition block establishes a particular of 120 different transpositions between the input circuits 22a-22e and the inputs of the switches 11-15 of this mechanism. Consequently, the considered calculator will work based on the combination or information it receives from the code reader in order to take this transposition into account. This function takes place 1 the input transposition device 69.

Input transpose 69.

As previously mentioned, the input transposition device 69 is supplied with information from the auto keys 35b, 36a and 36b via the respective cables 78b, 79h and 80h. The seven-stage step switches 140 in the input transposer 69 move, in the same way as the other step switches in the calculator, a series of contact arms in steps over the nine contact level, with seven fixed contacts on each, the movement is stopped at a point determined by information from auto key 35b.

The transposition device's step switch 141 has twelve levels with seven fixed contacts in each and moves its contact arms in the same way to a position determined by auto key 36a. The transposition device's rotary step switch 142 has fifteen levels, each with seven fixed contacts, and fifteen contact arms are moved step by step to a position determined by the output from auto key 36b.

The contact arms of code reader 68, which

relating to the path of the code frequency in the subscriber's decoder, is connected to the contact arms of the three step switches 140—142. In more detail, the three contact arms for code frequency f are connected via conductors 92a—92c to the respective contact arms for the first, fourth and seventh levels of step switch 140. The contact arms relating to code frequency fP are connected via conductors 92d—92f and to respective contact arms for second, fifth and eighth levels of step switch 140. The contacts that receive information from code reader 68 about the desired destination for code frequency f3 are connected via conductors 92g, 92j, 92k to the respective contact arms for third, sixth and ninth levels of selector 140. The code reader's 68 contact arms that record information regarding the desired path for code frequency f, for the selected program, are connected via conductors 92h—92m to the first, fifth and ninth levels of step switches 141. Finally, the contact arms that record information from the fixed contacts on the reader 68 about the desired path for code frequency pulses f-, connected via conductors 92p—92r to the first, sixth and eleventh contact arm of step switch 142.

The contacts on the first, second and third levels, counted from top to bottom, of tap-changer 140 are interconnected to achieve all possible permutations of them. More specifically, if the contacts on these levels are numbered 1-7, counting from left to right, then the permutations they represent, as the contact arms of these levels scan from left to right, are indicated in the following table:

All possible permutations are shown in the first six columns, and the seventh is a repetition of the first.

Similarly, the fourth, fifth, and sixth level contacts of tap-changer 140 are cross-connected to provide all possible permutations for conductors 92b, 92e, and 92j, while an identical cross-connect pattern forms the same permutations with respect to conductors 92c, 92f, and 92k . In view of this cross-connection pattern, the voltages applied to conductors 92a-02k, and which represent the paths of the code signal frequencies f,, f2 and f,, are conducted from the contact arms of step switch 140 to its contacts in accordance with the position the contact arms are allowed to go to below the scanning of the contact levels; this position is determined by which of the tap changer's contacts are supplied with voltage through conductors 78a—78g. Where the contact arms are stopped, voltage is transferred to those of the tap changer's contacts that are currently affected and the voltages appear on the output conductors to the far right of the tap changer in accordance with one of the seven possible positions that the contact arms are allowed to occupy.

The first three contact level output terminals of step switch 140 are connected to the second to fourth level contact arms of step switch 141, the fourth to sixth contact level output terminals of step switch 140 are connected to the sixth to eighth level contact arms of step switch 141, and the seventh to ninth contact level output terminals on tap-changer 140 is connected to the contact arms of the tenth to twelfth level on tap-changer 141. This latter in fact gives input transpose 69 an additional series of input conductors, namely those relating to the path of code frequency f,, and its various working positions give all possible transpositions with consideration of the code frequencies f,—f4. More specifically, the conductors 921-92a, which carry information about the desired path of code frequency f1, are added to input transposers 69 in step-up switch 141, and in view of the connections described, the four code frequencies f1-f4 can appear on the output terminals of step switch 141 in all possible orders.

The output terminals for the first to fourth levels of the step switch 141 are connected to the contact arms for the second to fifth levels of the step switch 142. Similarly, the output terminals for the fifth to eighth levels of the step switch 141 are connected to the contact arms for the seventh to tenth levels of the step switch 142, and the output terminals for ninth to twelfth level of step switch 141 is connected to the contact arms for twelfth to fifteenth level of step switch 142. The contact arms of step switch 142 are added to the conductors from code reader 68, which introduces information regarding the desired destination for the code signal of frequency f-. With the help of this tap-changer's connection pattern together with the corresponding patterns for tap-changers 140 and 141, all of the 120 possible transpositions can be achieved.

The particular one of the 120 transpositions which is the correct one for the subscriber bill is to be carried out, is selected by the positions the step switches 140, 141 and 142 are set in. This setting is achieved by selectively applying voltage to a contact in the set of fixed control contacts on each step switch so that the scanning of the contact arms is stopped. This control contact is selected, as already explained, by means of a conductor in each of the cables 78h, 79h and 80h to which voltage has been applied by the respective auto-keys 35b, 36a and 36b operating. And these car keys are naturally put into operation in response to the registration of the subscriber's identification number.

The selective setting of contact

the arms of these step switches, thus simulating the action of transpose block 22f in the subscriber's decoding mechanism, perceive the particular assignment of input conductors 22a-22e in the decoder to switches 11-15 determined by transpose block 22f. More specifically, three output conductors 110c, 110j, 110p from transposer 96, forming cable 110h, are routed to a binary/decimal converter 71 which produces specific information for switch 11. The selective setting of the transposer's contact arms, which in effect simulates the operation of the transpose block 22f, specifies which of the code signal frequencies f,—f, is to be assigned to switch 11 over these conductors. In other words, it picks out a trio of contacts, assigned a particular code frequency, from reader 68 and transmits the power state of the trio to the specified output conductors 110c, 110j and 110p of transponder 69.

Similarly, a particular output conductor trio from transposer 69 leads to converter 72 assigned to switch 12, while other three-conductor groups lead to converters 73, 74, and 75 assigned to respective switches 13, 14, and 15. These conductors to converters 72— 75, however, goes through price transpose 76 for reasons that will be clarified immediately.

Briefly explained, each of these receives in binary form the information or the guidelines which determine the particular one of the output conductors 1"—7" in the decoder to which the code frequency they represent is to be routed. The converters translate or read the binary information and convert it to a decimal indication of the particular output conductor, which will be explained later.

Before considering these converters in detail, the operation of the price transposer must be explained first, especially because the price transposer enters between transposer 69 and several such converters.

Price transpose 76.

The price transposer in the calculator is only in operation in cases where the bill is carried out for a subscriber of the class one has designated "cash subscribers". Those belonging to this class have a decoding mechanism which contains a price transposer which in its main features can be of the same type as transposer 76 which will now be described.

The transposer introduces a transposition in series or cascade with transpose block 22f, and the transposition introduced is changed each time a coin is placed on a coin container which controls the decoding mechanism. Accordingly, after the required number of coins have been placed, in accordance with the cost of the program, a known transposition will be made, as a result of which the transposer 76 in the calculator is similarly a variable transposer, which simulates or forms a counterpart to the price transposer in the cash subscriber's decoder.

When the contact arms of code reader 68 are moved stepwise over their contact levels in response to a program selection, selected by pressing keys on the keyboard 24, the first four contact arms, counted from top to bottom, will pick out price information for the selected program. They are connected via conductors 91a-91d and cable 91h to the input of binary/decimal converter 77 in fig. 23. The information found on the contacts on the code reader 68 represents the price information and is in binary form. Converter 77, which is of conventional construction, provides a voltage on any of ten output conductors and each of them indicates one of ten prices, including the zero price for those subscribers operating on a cost basis. Converter 77 may be approximately similar to converter 71, but this will be described in detail later.

As already mentioned, conductors 46a-46g are connected from the tenth level of fixed contacts on substitution switch 25 to seven horizontal rails on contact panel 77j and a single vertical rail on this is connected to the input of converter 77. Interconnections, indicated by dots, is made between the vertical rail and certain of the conductors 46a—46g, so that when one registers the identification number of any contact subscriber, switch 25 will apply voltage to one of the conductors 46a—46g which ends in such an interconnection, while the registration of a non-contact-subscribed will not result in a potential being applied via such interconnection to the vertical rails 77j.

In other words, the fourth digit of an identification number, which determines on which of the conductors 46a-46g there can be voltage, determines whether or not voltage is transmitted over one of the cross-connections to the vertical rail and from there to converter 77. The fact that whether or not there is voltage on the vertical rail of contact panel 77j will determine whether converter 77 responds to price information from code reader 68, supplied via cable 91h, or not. If the subscriber is not a cash subscriber, no voltage will appear on the vertical rail and converter 77 applies voltage to the first control contact of price transposer 76. This consists of a conventional, ten-step step-switch with nineteen contact levels and determines charge zero as the basis for the calculation for a given subscriber regardless of what price information it may have received from code reader 68. If, on the other hand, the bill is made for a contact subscriber, price transposer 76 will react to the price information received from the code reader and also reacts to information from input transposer 69.

The output terminals for the first and second contact levels on the step switch 142 are connected via the respective conductors 110a and 110b and via cable 110 to the first and second contact levels on the price transposer 76. The output terminals for the fourth to seventh contact levels on the selector 142 are connected via the respective conductors 110d—110g, to the contact arms for the third and fifth to seventh contact levels, on transposer 76. The output terminals for ninth to twelfth contact levels on step switches 142 are connected via the respective conductors 110k—110n and via cable 110 to the contact arms for eighth and tenth to twelfth contact levels on price transposer 76. The output terminals for the last two contact levels of step switch 142, namely fourteenth and fifteenth levels, are connected via the respective conductors 110q and 110r and via cable 110 to the contact arms for thirteenth and fifteenth contact levels of transponder 76. The output terminals for third, eighth and thirteenth contact levels of step switch 142 are connected across the respective conductors 110c, 110j and 110p, which form cable 1 10h, to the input terminals on the binary decimal converter 71.

The fixed contacts and contact arms for the fourth, ninth and fourteenth levels of transposer 76 are interconnected as shown to transpose the contact arms' incoming circuits in any of a number of possible patterns. If a contact subscriber is registered, a voltage appears on the vertical rail of contact panel 77j and binary/decimal converter 77 is allowed to respond to the price information supplied to it from code reader 68 via conductors 91a-91d. This information is received in binary form and converted to decimal form where a potential only appears on the output conductor in the converter that corresponds to the price dictated by the code reader. This voltage is applied to a corresponding fixed control contact on transposer 76 to indicate a selection of nine different prices which increase in steps of e.g. 25 cents. The contact arms of transpose 76 are moved incrementally to the column of fixed contacts corresponding to the price of the selected program, and another transposition is introduced, duplicating the one introduced by the subscriber's price transpose, by adding a number of coins corresponding to the program price.

As will be explained later, the output conductors from transposer 76 can be considered as another series of three-conductor groups, which is an extension of the type of conductor pattern introduced in contact panel 66, passed through code reader 68 and used in input transposer 69 to to transfer information about the route of the code frequencies with a conductor trio to represent one of the code signal frequencies f,—f,-. It should be enough here to identify the three-conductor groups from transposer 76; they are as follows — Group I contains conductors 117a, 117e and 117k; group II consists of conductors 117b, 117f and 1171; group III consists of conductors 117a, 117g and 117m; while the last group includes conductors 117d, 117j and 117a.

Just as transpose 69 switched the association of the code frequencies with its three-conductor output arrays in accordance with the controlled positions of the contact arms of tap-changers 140, 141 and 142, transpose 76 will also perform a transposition of the frequency assignment with respect to its conductor arrays when its contact arms are in any position other than the first, i.e. the positions to the far left as shown in fig. 23. The only difference of importance in the transpositions of the two mechanisms is that transpose 69 works on all five three-conductor groups, while transpose 76 hare works on four because one three-conductor group leads directly from transpose 69 to converter 71 for switch 11.

In addition to providing a transposition as described, transposition unit 76 also provides a visual display of the price of the billed program. For this purpose the contact arms for sixteenth, seventeenth, eighteenth and nineteenth contact levels are connected together and to the positive pole of voltage source 76j and most fixed contacts at those levels is connected an input circuit of one of three price indicator lamps 78-80. These indicator lights together show the selected program's price. Lamp 78 indicates e.g. hundreds of cents or dollars, lamp 79 tenths of cents and lamp 80 mere cents. Lamp 78 has two input circuits. If voltage appears on one, the number one indicates, and with voltage on the other, the number two is indicated. Lamp 79 has four input circuits for selectively displaying zero, two, five or seven, and lamp 80 has two inputs for displaying either the number zero or five. For convenience, appropriate numbers are placed on the drawing next to each of the inputs to the lamps 78-80.

The nineteenth level fixed contacts of transposer 76 are connected over a series of conductors and through a cable 83 to the input circuits of decimal/binary converter 129.

Converters 71—75.

As previously mentioned, the information from code reader 68 regarding the paths for the different code frequencies f,—f3 with regard to conductors 1"—7",1 has been represented in binary form in order not to complicate the circuits too much. It is therefore necessary to convert this binary information into its decimal equivalent and this is carried out in the converters 71 to 75, which are exactly the same.

The output terminals from the first, sixth and eleventh contact levels of price transposer 76 are connected via the respective conductors 117a, 117e and 117k and via cable 117 to the input circuits of binary/decimal converter 72. The output terminals for the second, seventh and twelfth contact levels of transposer 76 are connected via the respective conductors 117b, 117f, 1171 and via cable 117 to the input circuits of binary/decimal converter 73. The output terminals for the fourth, ninth and fourteenth contact levels of transponder 76 are connected via conductors 117c, 117g and 117m to the inputs of binary/decimal converter 74. The output terminals for fifth, tenth and fifteenth contact levels are connected via conductors 117d, 117j and 117n and via cable 117 to the input circuits of binary/decimal converter 75. Converter 71 is connected directly via conductors 110c, 110j and 110p to transpose 69.

Converter 71 has three relays 145—147 and each relay has one terminal connected to an incoming circuit and its other terminal to the negative pole of the voltage source 148. A group of seven inverters 150—156 operates by means of the three relays so that a voltage from the source 149 may be applied to any of seven output conductors 112a-112g which are connected via cables 112h and 112 to adder 56. The selected of the seven conductors 112a-112g to which voltage is applied from the source 149 indicates the particular of the seven output circuits 1 "—7" to which the subscriber's switch 11 must be set; and for the sake of convenience, this correlation is shown in the drawing with the designation 1"—7" at conductors 112a—112g.

When hare relay 145 energizes, a potential from source 149 is passed through the "closed" contact on switch 150 and

the "broken" contacts on terminals 151 and 155 to conductor 112a to indicate that switch 11 is to be set to output circuit 1". When only relay 146 is energized, voltage from source 149 is conducted through the open contacts on terminals 150 and 156 and through the closed contacts on face 153 to conductor 112b. When both relays 145 and 146 energize, a voltage from source 149 passes through the closed contacts on faces 150 and 151 and through the broken contacts on face 154 to conductor 112c. When only relay 147 pulls, voltage is passed through the broken contacts on face 150, the closed contacts on face 156 and through the broken contacts on face 152 to conductor 112d and indicates output circuit 4". When both relays 145 and 147 are energized, a potential is passed through the closed contacts on face 150, the broken contacts on face 151 and the closed contacts on face 155 to conductor 112e. When both relays 146 and 147 are energized, a positive potential is passed through the broken contacts on reverse 150 and the closed contacts on reverse 156 and 152 to conductor 112f. And then finally, when all three relays energize, voltage from source 149 is passed through the closed contacts of inverters 150, 151 and 154 to conductor 112g and thus indicates that switch 11 must be set so that it is connected to output circuit 7".

The seven output conductors 113a—113g of converter 72 are connected via cables 113h and 112 to the contact arms of addition unit 57. Output conductors 114a—114g of converter

73 is connected through cables 114h and 112 to the contact arms of addition unit 58. Output conductors 115a—115g of converter 74 are connected through cables 115h and 112 to the contact arms of addition unit 59. Output conductors 116a—116g from converter 75 are connected through cables 116h and 112 to the contact arms on addition unit 60.

Converter 71 supplies addition unit 56 with information about the exact position switch 11 must occupy. In the same way, the converters 72-75 supply the respective adding units 57-60 with information about the positions the respective switches 12-15 must occupy in order to fulfill the requirements set by the particular, selected program.

Tape perforator 82.

When a subscriber's identification number has been registered on the keyboard and the code calculation takes place to determine the desired button settings, it is desirable to obtain a recording of what is happening. Accordingly, a tape punch 82, of conventional construction, is connected to the outputs of the decimal/binary converters 121-129 for storing the necessary information. The subscriber's identification number is carried to the perforator through cables 47h, 50h, 64h, 66h and 68h from the respective substitution switches 25-30. Conductors 56a-56f and conductors 55a-55e from the program keys on keyboard 24 are connected via respective cables 56h and 55h to decimal/binary converters 127 and 128 to supply tape punch 82 with information about the particular program selected. The selected program's price is represented by information from transposer 76 which is fed to converter 139 via cable 83. It has been shown that the decimal/binary converters 121-129 ensure that the circuits supplied to the tape perforator do not become unnecessarily complicated. Perforator 82 thus receives three pieces of information, namely the subscriber's identification number, the selected program and the cost of the program. These individual pieces of information are individually registered or recorded on tape in a conventional manner.

Illustrative calculation operation.

In order to gain a clearer understanding of the invention, it is helpful to describe the working method of the entire calculator as a reaction to the registration of a typical identification number and a typical program selection. It must be remembered that on all drawings the thicker, solid or dotted lines indicate the active circuits for the identification number, which will be described immediately.

Suppose that the particular subscriber chosen as an example has previously been assigned identification number 374625. Suppose that the subscriber calls the subscriber television switchboard and asks for the correct setting for his particular decoding mechanism needed to decode a shown program named program D3. The operator presses down appropriate keys on the keyboard 24 to record the identification number and the program selection. This results in voltage from the source 24a being applied to conductor 48c (in response to the registration of the first digit 3), also applied to conductor 53g, conductor 51d, conductor 41f, conductor 54b and conductor 52e (in response to the registration of the sixth digit). In addition, conductors 56d and 55c are energized in response to the registration of program number D3.

The voltages that are impressed on the six conductors belonging to the identification number are transferred to the corresponding fixed control contacts in the substitution switches 25-30 so that the contact arms of these switches stop in the position determined by the control contact that is energized. In more detail, switch 25 is moved step by step to the contact column containing the fixed control contact connected to conductor 41f, as shown by dashed extensions of the contact arms. Switch 25 is moved stepwise to the contact column containing the control contact connected to conductor 48c, switch 27 is moved stepwise to the contact position determined by conductor 5ld, switch 28 is moved to a position determined by the potential on conductor 52e, switch 29 is moved to a position determined by the potential on conductor 53g, and substitution switch 30 is moved step by step to a working position containing the control contact connected to conductor 54b.

Voltage from the source 25b is carried over contact arm 25a, conductor 43f and conductor 49d to one of the fixed control contacts on auto key 32a, to the contact arm for the fourth level on auto key 31a, and to a contact arm on the fourth level on auto key 36b. Voltage from source 36b is carried over contact arm 26a, conductor 42c and conductor 44g to a control contact on car key 31a, to a contact arm on car key 35b, and to a contact arm on car key 36a.

Potential from source 27b is carried over contact arm 27a, conductors 62d, 65e to a control contact on auto key 34a, to a contact arm on auto key 33a, and to a contact arm on auto key 32b. Source 28b applies a voltage across contact arm 28a, conductors 61e, 63e to a control contact on auto-key 33a, to a contact arm on auto-key 32a, to a contact arm on auto-key 31b. Voltage from source 29b is fed through contact arm 29a, conductors 58g, 67a to a control contact on auto key 36a and to contact arms on auto key 35a and auto key 34b. A potential from source 30b is passed over contact arm 30a, conductors 57d, 59d to a control contact on car key 35a and to contact arms on car keys 34a and 33b. The auto-keys are moved stepwise to assume positions dictated by the control contacts which are energized, the alternating positions of the auto-keys' contact arms are shown by dashed lines.

A potential from one of the sources 25b-30b is transferred to a selected output circuit on each of the twelve auto keys. More specifically, the voltage which has been carried over conductor 49d to a contact arm of auto key 31a is carried on over this contact arm and through the circuit of auto key 31a shown in thicker lines, to output conductor 69d. In addition, the voltage from source 25b is passed over solder 49d, a contact arm on car key 36b and a circuit on this car key which appears on output conductor 80c. The voltage from source 26a which is applied over conductor 44g to a contact arm on auto-key 36a is fed through a fixed contact on this auto-key to output conductor 79a. In the same way, the voltage is applied from source 26b, conductor 44g and a contact arm to auto key 35b and then to output conductor 78c.

In a similar manner, voltage from source 27b is transferred to output conductor 73c of auto-key 33a and to output conductor 72b of auto-key 32b. Voltage from source 28b is applied to output circuit 71b on auto key 32a and also to output 70a on auto key 31b. Source 29b supplies a potential to output conductor 77d of autokey 35a and also to output conductor 76f of autokey 34b. A voltage from source 30b is carried over conductor 59c to output 75a on auto key 34a and to output 74a on auto key 33b.

In this way, and in response to the entry of the number 374625 on the keyboard 24, voltage is applied to conductors 69b, 70e, 71b, 72b, 73c, 74a, 75a, 76f, 77d, 78c, 79a and 80e, and each of these conductors is connected to a specific one of the control contacts on one of the memory selectors 37—45 or to the step switches 140—142. The selectors and tap-changers will therefore react to the voltage applied to their control contacts and take corresponding positions. Each selector makes a connection from its contact arms to a selected memory unit which is connected to the contact column in the controlled position for sorting that unit's representation of the exact shape on one of the index dials in the subscriber's decoder. Considered in more detail, selector 37 connects its contact arms to the memory unit connected to a contact column containing the control contact to which conductor 69d is connected and introduces the characteristics of cam llb into the mechanism of the subscriber having identification number 374625. Selector 38 introduces the transposition block or memory unit which is connected to the contact column associated with conductor 70e to provide a representation of the shape of cam disc 12a. Similarly, the memory units in transpose blocks 48-54 are connected to the contact arms of the respective selectors 39-45 to bring in the characteristics of the respective cams 12b, 13a, 13b, 14a, 14b, 15a and 15b.

Tap switches 140-142 assume positions dictated by their live control contacts and simulate the transposition patterns found in the subscriber's transpose block 22f.

You have now determined all the parameters for the decoding mechanism for subscriber 374625. Now you must observe what happens when the program selection keys D and 3 are pressed. Voltage from source 24a is carried over conductors 56d and 55c to respectively a fixed control contact and contact arm on program selector 67. This selector assumes, as a reaction to the voltage it has received on the fixed control contact, a working position where its contact arms touch the contact column that contains the control contact. Voltage from source 24a is therefore passed over conductor 55c, a contact arm on program selector 67, conductor 88c to a fixed control contact on code reader 68. The code reader moves its contact arms to the position determined by the active contact. Since the entire contact column under the program designation D3 in main code panel 66 is connected to a contact column on code reader 68 which is in the position the selector has been moved to, voltage from source 66j will be found on corresponding fixed contacts in reader 68. In other words, the voltage conditions on contact column D3 on the code panel is copied on the contact column the code reader's contact arms touch. In this way, voltage from source 66j will be applied to the contact arms of code reader 68 to conductors 91a, 91d, 92b, 92e, 92f, 92g, 921, 92n and 92r. This voltage distribution pattern on the wires of cables 91h and 92h is a binary representation of the particular path of the frequency pulses between the input and output circuits of subscriber 374625, and of the price for program D3.

The potential conditions of the conductors 91a-91d are transferred to an input of binary decimal/converter 77 to convert the binary representation into one particular of nine possible values. At this time, however, there is no voltage on the vertical rail of contact panel 77j and converter 77 does not respond to the price information. This particular subscriber is a fee subscriber and the voltage from source 25f which is carried over contact arm 25e on substitution switch 25 to conductor 46f, is not transmitted to the vertical rails on contact panel 77j because there is no cross connection there from conductor 46f. Thus, price transpose 76 remains in its initial or output position as shown in the drawing.

The voltage from source 66j is applied to conductor 92b, is transmitted further through step switches 140, 141 and 142 and arrives at output conductor 110g. In the same way, the voltage on conductors 92d, 92e, 92f, 92g, 921, 92n, 92q and 92r is passed through the three step selectors in input transposer 69 and then acts on the respective output conductors 110c, 110j, 110p, 110a, 110r, 110k and 110q. The pattern the voltage from source 66j forms, when it appears on the output conductors of input transporter 69, represents two individual pieces of information in binary form, namely the particular one of the code frequencies f,—f, to be supplied to each of the switches 11—15, and also the particular position each of the switches 11—15 must be set to satisfy the desired connections between input circuits 22a—22c and output circuits 1"—7" of the decoder mechanism, as dictated by the control column under program D3 on contact panel 66.

It will be noted that the output conductors 110c, 110j and 110p of transpose 69 lead directly to converter 71 which determines the specific information for switch 11. If these conductors are followed backward through the transpositions performed by unit 69 for the assumed operating conditions, it is apparent that those through the contact arms of transposer 69 get the same potential ratio as the code reader conductors 92d, 92e and 92f. These conductors indicate the assigned path for code frequency f., and this makes it clear that switch 11 in the subscriber's decoder must output this particular code frequency.

As this explanatory example concerns a subscriber who does not belong to the "cash subscribers", no further transposition is introduced in price transposer 76, therefore one can, by following backwards the other output conductors on input transposer 69, through this unit's transpositions, determine the distribution of the code signal frequencies of the other switches. In the present case it turns out that switches 12, 13, 14 and 15 are assigned the respective code signal frequencies f5, fu<f>4 and fr

The binary information at the output of unit 69 is now converted into decimal form. The voltage on conductors 110c, 110j and 110p causes relays 145-147 in binary/decimal converter 71 to energize. Then a positive voltage from source 149 is fed through the end contacts of inverters 150, 151 and 154 to output conductor 112g, which suggests that switch 11 must be set so that its input circuit and code frequency f;, are connected to output circuit 7".

The voltage on each of the conductors 110k and 110q is transmitted through certain of the fixed contacts of the price transposer 76 to the respective conductors 117e and 118k which are then connected to the input of converter 72. This converter reacts to this and applies voltage to output conductor 113f and indicates that the input circuit of the switch 12 and code frequency f. must be connected to output circuit 6".

The voltage on conductor 11 Og is passed through transposer 76 to output conductor 117f and then to the input of converter 73, which applies a voltage to output conductor 114b to indicate that switch 13 should be set so that code frequency f goes to output circuit 2".

The voltage on conductors 110e and 110r is transmitted through transposer 76 to output conductors 117c and 117m then to the input of converter 74 which provides a voltage on output conductor 115e to indicate that switch 14 must be set so that its input circuit and the 'code frequency f' are fed to output circuit 5" .

The voltage on conductor 110a is transmitted through transposer 76 and output circuit 11 Td to the input of converter T5 and provides a voltage on conductor 116a to indicate that switch 15 must be set so that code frequency f3 is fed to output circuit 1".

The potential conditions established in this way on the output conductors of the converters Tl to 75 are transferred to the adding units 56 to 60. In more detail, the voltage on conductor llg in the converter 71 is transferred to a contact arm of the adding unit 56 and the potentials on the output conductors 113f, 114b, 115e and 116a, from the other converters the respective, selected contact arms are applied to the adding units 57-60 as shown.

The calculator is now ready for the code build-up process, this process comprising a number of operational steps each of which determines the required setting for one of the buttons 16-20 in the subscriber's decoding mechanism. A potential from source 25d is passed over ninth-level contact arm 25c of substitution switch 25 and over conductor 45f to a selected, horizontal rail in transposition block 55. For the selected rail, there is a connection to a vertical rail indicating that disk lia for subscriber 374625 has a depth or active sector number 4 in engagement with intersection mechanism lic, as shown in fig. 1. Adder unit 56 is moved step by step to the position where it touches a contact column comprising the one marked 4 on block 55 to inform the calculator that the subscriber's index dial has previously been set by a service man so that the cam sector

4 on disc lia is active. Conductor 112g from converter 71 suggests to addition unit 56 that the switch must be set so that input circuit 23b, which carries the rectified frequency pulse f2, is connected to output circuit 7". The voltage on conductor 112g is thus passed through addition unit to arrive at output circuit 96c, this suggests that sector 3 on disc 11b is necessary for the intersection mechanism 11c, which is controlled by this disc and disc 11a jointly, to function and set switch 11 to output circuit 7". The next step the calculator must perform is to find the angular position of cam disc 11b which will place sector or depth 3 in engagement with intersection point mechanism lic. Accordingly, the potential on conductor 96c is transferred to a contact arm of selector 37, then over a selected vertical rail in the thereby selected memory unit and to the horizontal rail via a connection between the rails. According to the pattern of depths on disc 11b for subscriber 374625, which is represented by the selected memory unit, position 6' will place the desired sector at depth 3 in engagement with the intersection mechanism lic. The voltage that appears on conductor 112g is carried over conductor 95c and through selector 97 to output conductor 95f, and to indicator lamp 61. The lamp displays the number 6 and this indicates to the operator that the subscriber's button 16 must be set to position 6' for switch 11 to work correct.

When button 16 is set in this way, the subscriber's disc 12a will also rotate as it is firmly attached to the shaft 16a and therefore the active sector on disc 12a must be registered. This is achieved by passing the voltage on conductor 95f to one of the contact arms of selector 38 and then through selected vertical and horizontal rails in a selected memory unit and to conductor 97e. The selected memory unit indicates that when button 16 is set to position 6', depth 5 of disk 12a is moved into engagement with intersection point mechanism 12c, as shown in fig. 1. The voltage on conductor 97e is transferred to a fixed control contact on addition unit 57, which causes rotation of this into a column of fixed control contacts in line with conductor 97e. Converter 72 transmits a voltage across conductor 113f to a contact arm on addition unit 57 to indicate that switch 12 must be set so that input circuit 23e is connected to output circuit 6". The voltage on conductor 113f is passed through the addition unit where an automatic calculation operation takes place to produce a voltage on conductor 99a which indicates that sector or depth 1 on disc 12b must be used for switch 12 to make contact with output circuit 6". The voltage on conductor 99a is passed through a contact arm of selector 39, a selected vertical rail in the selected memory unit and a horizontal rail to conductor 98b to indicate that for the particular shape of cam disk 12b in the subscriber mechanism, disk 12b must occupy position 2' for to place sector 1 in engagement with intersection mechanism 12c, as shown in fig. 1. The voltage on conductor 98b causes indicator lamp 62 to show the number 2 and thereby tell the operator that button 17 must be set to position 2' for switch 12 to work correctly.

The position of the other buttons 18-20 is determined in a similar way. Briefly, the voltage on conductor 98b is transferred to a contact arm on selector 40 and through a selected vertical rail on the selected memory unit and a horizontal rail to conductor 101f to indicate that depth 6 of disc 13a is engaged with intersection mechanism 13c when button 17 is set in position 2'. The voltage on conductor 101f is fed to addition unit 58 to start it up.

The voltage on conductor 114b from converter 73, which indicates that switch 13 must be set to output circuit 2", is transferred to conductor 103c and determines that sector 3 on disc 13b must be added. One must remember that switch 13 is what one calls a "modulo 7" -arrangement, in that the desired of seven output circuits can be reached by adding two depths or sectors which together make up the number of output circuits, or by adding two depths which together make seven plus the number of output circuits. As sector 6 on disk 13a is 1 engagement with the intersection mechanism 13a and as the switch must be connected to output circuit 2, this can be achieved by using sector 3 on disc 13b.

The voltage on conductor 103c is passed through a contact arm on selector 41 and a selected vertical and horizontal rail on a selected memory unit to output conductor 102a and to indicator lamp 63 and cause the lamp to display the number 1. This shows that button 18 must be set to position 1' in order for switch 13 should work richly.

The voltage on conductor 102a is transmitted to a contact arm on selector 42 and then via special vertical and horizontal rails in the selected memory unit to conductor 104c indicating that with button 18 in position 1, depth 3 on disc 14a is actively engaged with mechanism 14c, as shown on fig. 1. This information is fed to addition unit 59 for its activation. A potential from converter 74 appears on conductor 115e, which shows that switch 14 must be set to output circuit 5", and is transferred through adder 59 to output circuit 106b. This means that a depth 3 on disc 14b must be added to depth 3 on disc 14a in order to set switch 14 to output circuit 5". The potential on conductor 106b is transferred to a contact arm on selector 43 and via special vertical and horizontal rails in the selected memory unit to output conductor 105c and then to lamp 64 to indicate that for this particular form of disc 14b, button 19 must be set to position 3' .

The voltage on conductor 105c is also fed to a contact arm on selector 44 and through special vertical and horizontal rails

to output conductor 107e, which shows that when

button 19 is in position 3', sector 5 on disc 15a is engaged with intersection point mechanism 15c. The voltage on conductor 107e is transferred to a control contact on addition unit 60 and causes this to start.

A voltage appears on conductor 116a from converter 75 and suggests that switch 15 must be set to output circuit 1". A calculation is performed in adding unit 60 and a voltage appears on output circuit 108c and determines that depth 3 on disk 15b will satisfy the requirement. The voltage on conductor 108c is led to a contact arm on selector 45 and then through a vertical rail in the memory unit that represents the shape of disc 15b, and over a horizontal rail to output circuit 109g. The desired position for button 20, namely position 7', is led to indicator lamp 65 which shows the number 7.

Now all indicator lamps 61—65 are lit and show the code combination or button settings 62137. The operator passes this information on to the subscriber.

The operator can also note that this information has been communicated, for use when paying for the programme. However, there are devices in this calculator to automatically record details relating to the transaction. In more detail, the voltage is applied to conductors 47f, 50c, 64d, 66e, 60g and 68b from the respective substitution switches 25-30 and on to the respective decimal/binary converters 121

— 126 whose outputs are fed to tape perforator 82 for recording a representation of the subscriber's identification number. The voltage on the conductors 56c and 56d from the program keys on the keyboard 24 is also passed through converters 127-128 to tape perforator 82 which registers the particular program selected. Information about the cost of the program, which only concerns cash subscriptions

nents, is transferred from price transposers 76 through converter 129 to tape perforator which registers the price of the selected programme. In the particular example that has been described, transposer 76 was of course not used, as the subscriber in the example was not a cash subscriber and no price was recorded in tape perforator 82. Printing of the bill can be done in this case by reviewing the registered information regarding the selected programs. Alternatively, price information from code reader 68 can be supplied to the tape perforator independently of the price transposer to form a bill register for all subscriber categories.

As some of the calculator's functions must necessarily take place after a preceding operation has been completed, arrangements must be made for successive activation of some of the step switches. Since these are of conventional construction, it is a relatively simple matter to prevent them from receiving working voltage until the operations required have first been carried out. Operating voltage for the substitution switches 25—30, the auto keys 31a—36b, program selector 67 and code reader 68 can be supplied during or immediately after the registration of the subscriber's identification number and program selection. Operating voltage is then sequentially applied to memory selectors 37—45, tap switches 140—142, price transpose 76, adder units 56, 57, 58, 59 and 60. Such supply of operating voltage in sequence to the various tap switches can be achieved by using, for example, another rotary tap-changer which is initiated by the operator so that voltage is applied as required. The necessary circuits to ensure multi-stage operation of the calculator have been omitted to avoid unnecessary complication of the drawings.

Also, the circuitry that resets all the various tap-changers to their respective reference positions is also omitted from the drawings for the sake of clarity. These circuits are of completely conventional construction and can be initiated by the operator after the calculator has performed a complete cycle of operation and has displayed the required setting pattern for the buttons.

The calculator can also be used for the reverse task. Instead of recording a subscriber's identification number to determine the particular shapes of the index dials in his transposition mechanism and then determining the button settings needed to watch a particular program, it is also possible to use the calculator to select the shape of each dial needed for a subscriber who has a given identification number. To clarify this further, any six-digit number can be entered on the keypad 24 to activate switches, autokeys, selectors and input transposers. Akalas can be attached to the harnesses and the input transposer to indicate the special position these switches take in response to the registration of the six-digit number. Accordingly, the memory unit each of the selectors selects can be observed and will indicate the shape of the various index disks needed in the transposition mechanism corresponding to the registered six-digit combination. Also, the required transposition pattern for block 22f will be indicated by the step switches 140

—142. A coupling mechanism can then be provided which has such index discs and such a transposition pattern in block 22f; since the mechanism will belong to this registered number. In the following, a summary will be given: The calculator for subscriber television according to the present invention determines the setting of a decoding mechanism (shown in Fig. 1) which has a number of working positions, namely the different position combinations for the buttons 16-20 and consequently also the index cams 11b—15b and 12a—15c, and each of these positions establishes a predetermined code state. In more detail it is seen that for a given pattern of button settings the switches 11-15 will occupy a number of positions which provide a special connection between the input circuits and the output circuits. The calculator has devices (keyboard 24, contact panel 66, program selector 67 and code reader 68) for obtaining information representing a selected code state (namely a selected pattern of conductive connections between the input circuits and the output circuits) which must be established in the decoder (Fig. 1) for to decode a given subscription television program. The calculator also contains devices (keyboard 24, substitution switches 25-30, autokeys 31a-36b, selectors 37-45 and transposition blocks 46-55) for

producing information representing the correlation between the decoder's

working positions and code states. Control equipment including input transposers

69, price transpose 76, binary/decimal converter 71-75, adders 56-60 and indicator lamps 61-65, respond to the information from both devices and

determines the necessary working position of the decoding mechanism to establish the selected code state.

Claims (14)

1. Calculator for subscription television specially designed for the purpose of determining the necessary setting information for the correct setting of each of a number of decoding mechanisms used in a subscription television system, where each decoding mechanism is of the type that has several working positions, each of which establishes a predetermined code state, and is so constructed that the decoding mechanisms must be selectively set by a subscriber, characterized by program selection devices (24, 66—68) to deliver information representing a specially selected code state for a predetermined one of the decoding mechanisms (11— 20), decoder identification devices (24-55) which supply information representing the correlation between working positions and code states in said decoding mechanism (11-20); and a decoder setting means (56-65, 69, 71-78) which responds to the information from both said devices for determining the special working position necessary for the relevant decoding mechanism to establish said selected code state. 2. Calculator according to claim 1, where the decoding mechanism comprises a number of movable code-determining devices, which in each of the mentioned working positions together form a prescribed code pattern which establishes said decoding mechanism in a corresponding predetermined code state, characterized in that the program selection devices (24, 66-68 ) is designed to deliver information that represents the code pattern for said code-determining devices (11-20) which corresponds to said selected code state. 3. Calculator according to claim 2, where each movable code-determining device comprises two manually adjustable, independent elements that each have a number of positions, and which together control the working position of its associated code-determining device for establishing several different code states, characterized in that said decoder setting means (56—65, 69, 71—76) determines the particular position to which one of said adjustable elements (lia—b to 15a—b) must be set, when the other element is already set in a given position, to influence said code-determining device (11-15) so that it establishes said selected code state. 4. Calculator according to claim 3, where said decoding mechanism comprises a movable, actuable mechanism connected to the code determining device for establishing different code states, and the manually adjustable elements comprise first and second independently of each other, manually adjustable multi-section index devices which in each position has an active section for the exercise of a driving effect determined by its assigned value within a predetermined range of values for a determined property of the active section, and jointly operates said influencing mechanism to set the code-determining device in one of its positions in accordance with the combined driving effects exerted by the active sections of both said index devices, characterized in that said decoder setting means comprises devices (e.g. 56) connected to said devices for decoder identification (24-55 ) to determine the active section of the first index word ning (f. e.g. Ila) when this is set in a predetermined position, devices (71-75) for determining the active section which is necessary on said second index device (e.g. Ub) to cause said code-determining Device (e.g. 11) is moved to said selected position, and devices (e.g. 56) for determining the particular position of said second index device which brings the required section into working position. 5. Calculator according to claim 1, where each of a relatively large number of multi-position decoding mechanisms having a series of input circuits and a series of output circuits, in each position establishes a predetermined connection pattern between said input and output circuits, where each of said decoding mechanisms also has a transposing means which introduces a fixed transposition to its input circuits specific to each decoding mechanism, characterized in that the program selection means (24, 66 —68) is adapted to supply information representing the selected pattern of connections to be established in each decoding mechanism ( 11-15) to effect decoding of said given subscriber television program, and where said devices (24-55) for decoder identification deliver information representing the correlation between positions and connection patterns in the selected of said decoding mechanisms, said devices for identification also includes devices (31-36, 140-142) to provide information representing the particular transposition introduced by the transpose device into the selected decoding mechanism. 6. Calculator according to claim 5, where said transposition device is of a coin-activated, variable type which introduces a selection of several different transpositions to said input circuits in accordance with the number of coins that are added, characterized in that said program selection device (24, 66— 68) also provides information representing a particular transposition to be introduced by said transposing device for said given program, and the decoder setting means (55-65, 71-76) determine the particular position of said decoding mechanism (11-15) which is necessary for the creation of said selected pattern after a predetermined number of coins, corresponding to the cost of the selected program, have been placed on the coin-actuated transposition device. 7. Calculator according to claim 1, characterized by a storage device (66) for storing information provided by the program selection devices (24, 66-68), and a code reader device (68) connected to the storage device (66) for reading the information stored therein. 8. Calculator according to claim 1, characterized in that said devices for decoder identification (24-55) comprise storage devices (46-55) for storing information representing the correlation between working positions and code states, and devices (37-45) for reading the information stored in the latter storage device. 9. Calculator according to claim 1, where said decoding mechanism is one of a number of such mechanisms and is assigned to a particular one of a relatively large number of subscribers, characterized in that said program selection devices (24, 66-68) are able to register the information which represents the selected code state, and the decoder identification device is capable of recording for the subscriber the identification information that represents the correlation between working positions and code states for said decoding mechanism (11-15). 10. Computing device according to claim 9, wherein the decoding mechanism assigned to each subscriber is arranged to establish a predetermined code state in accordance with a correlation pattern that is different for each decoding mechanism, and the program selection device (24, 66-68) is able to register it information representing said special state that must be established in any of said decoding mechanisms (11—15) in order to have a given subscriber television program decoded, characterized in that the device (24—55) for decoder identification includes storage equipment (46—55) for storage of information representing the correlation pattern for the decoding mechanisms assigned to each subscriber, and devices (37-45) connected to said storage apparatus for recording an identification of a selected subscriber to derive information about the particular correlation pattern in the decoding mechanism which is assigned to the selected subscriber, and where said decoder setting mechanism (56-65, 69, 71-76) determines the particular working position required in the decoding mechanism of the selected subscriber to establish said selected code state. 11. Computing device according to claim 10, characterized in that said program selection devices comprise storage equipment (66) for storing information that represents the code state that must be established in the decoding mechanism in order to have each one of a number of different subscriber television programs decoded, and devices (67 ) connected to said storage apparatus (66) for selecting the information relating to one of the programs in order to clarify the code state necessary to decode the selected program, said decoder setting means (56—65, 69, 71—76) determines the particular working position of the decoding mechanism needed to establish the code state needed to decode the selected program. 12. Calculator according to claim 11, in which the decoding mechanism has a set of distinguishing characteristics which in particular determine the correlation between the working positions and their decoding state, characterized in that the device (24-55) for decoder identification is capable of reacting to registration of a subscriber identification number assigned to said selected subscriber and which has a number of digits that is less than the number of distinguishing characteristics, for generating information that represents said characteristics and thereby represents the correlation between working positions and code states in said decoding mechanism (11-15). 13. Calculator according to claim 12, in which the distinguishing characteristics of the decoding mechanism represent a large number of possible code patterns, characterized in that the device for decoder identification comprises organs (25-30, 31a-b-36a-b) which react to the registration of said identification number for said subscriber and produces a number of elements of information, greater than the number of digits in said identification number, which specify said decoding mechanism's distinguishing characteristics, representing one selected from a large number of possible patterns, storage apparatus (46-55) for storing information representing several possible patterns of distinguishing characteristics, and devices (37-45) for utilizing the aforementioned elements with information to derive from said storage apparatus information regarding predetermined distinguishing characteristics. 14. Calculator according to claim 13, characterized in that said device, which responds to the registration, has the form of substitution devices (25-30) which can provide a representation of a completely different replacement number consisting of digits that respond to the registration of the said subscriber ID ication number and adding devices (31a-b—36a-b) which respond to the representation of the replacement number and add the digits of the replacement number in various combinations and obtain said number of elements of information, which number is greater than the number of digits in the replacement number.