746,666. Automatic exchange systems. STANDARD TELEPHONES & CABLES, Ltd. Sept. 11, 1953 [Sept. 19, 1952], No. 23535/52. Class 40 (4). Recording means comprises a number of stores allotted individually to user circuits and control means associated with means for reading and recording in said stores intelligence relating to said user circuits. The invention is described with reference to a magnetic drum but is applicable also to a static magnetic matrix, a ferroelectric storage matrix, a cathoderay tube storage device or compression waves in acoustic delay lines such as mercury delay lines and magnetostrictive delay lines. First embodiment. Each track on the drum has a number of sections, each associated by a time position pulse with a particular subscriber's line. As seen in Figs. 1, 2, each subscriber's section comprises sub-divisions for timing, temporary fee store, and permanent stores for single, double, triple and quadruple fees. The waveforms shown are generated as the corresponding elements of the track pass under the reading head. These waveforms are applied to the several gates shown in Figs. 3-5 to control the firing of trigger pairs of gas-tubes F1-F6 and one or other of the five sections of register F7. Functions of tubes F1-F7. F1 is a read flip-flop, F1A conducting when 1 is read and F1B when O is read. F2, Fig. 4, is controlled by the P lead of the subscriber, F2D conducting when a meter pulse is present and F2C when it is absent. F3, Fig. 3, is part of an addition circuit, F3E conducting when there is to be no change and F3F when the recording is to be reversed, i.e. when 1 is to be added. F4, Fig. 5, controls the recording circuit, F4G conducting when 1 is to be recorded and F4H for O. F5, Fig. 4, indicates with F5J conducting that the potential on the P lead has changed, with F5K conducting no change. F6T, Fig. 3, conducts normally but when element ET4 registers 1 indicating the elapse of 800 m./secs. with no change on the P lead, F6S conducts to effect transfer from the temporary fee store to the appropriate permanent store. This transfer is effected by operating the appropriate section S, D, T, Q of multi-stable register F7 in which section N is normally conducting. Operation. Absence of potential on P lead. PN is the time position pulse used to gate subscriber's line circuit N into section N on the magnetic drum and is operative each time the track section N passes the reading head. Starting with a blank record, when the first element EM1 of section N passes the reading head, gate G1 opens so that F2 tests the P lead of subscriber N. As there is no metering condition F2C conducts and O in element EM1 causes F1B to conduct. Accordingly, gate G18 operates F5K to indicate no change of condition on the P lead. Gate G25 operates F4H to record O in element EM1, while F5K operates gate G4 to make F3F conduct to add 1 to the timing register by opening gate G21 as ET1 passes the reading head whereby F4G conducts to record 1 in element ET1. G10 then restores F3 to F3E conducting. Successive O's in elements ET2-ET4 keep F1 at F1B conducting so that G26 causes F4H to record O each time. The remainder of the section passes the reading head without alteration. The result of the first scan is that 1 has been entered in the timing store. This process continues for successive scans. Appearance of pulse on lead P. The pulse prepares gates G1 and G2. When EM1 is read G1 causes F2D to conduct so that gate G15 operates F5J showing that a change of condition has occurred on the P lead and gate G19 operates F4G to record 1, this recording remaining as long as potential exists on the P lead. With the appearance of waveform WT, gate G28 conducts to operate F4H to record O in positions ET1-ET4, while gate G3 resets F2 to F2C. In the manner described in Specification 744,352, [Group XIX], 1 is entered into element EM2 and 1 into the temporary fee store EF1-EF3, the marking in EM2 preventing any further addition into EF1-EF3 while the meter pulse persists. This is effected by pulse tm2 opening gate G2 to operate F2D so that G22 operates F4G to record 1 in EM2. The appearance of EF1 resets F2 and through G24 causes F4G to record 1, F3 then being reset through G10. At the next scan if the pulse on lead P persists, F2D conducts and through G17 operates F5K which through G4 and F3F causes the addition of 1 to the timing store. The rest of the section is unaltered. The marking in EM2 is removed at the end of the pulse and if a further pulse occurs before fee transfer the mark is re-entered in EM2 and a further unit added to EF1-EF3 and so on. Assume now that the pulse has ceased. F2C and F1A therefore conduct when EM1 is read and through G16 energize F5J to indicate a change on the P lead. Through gate G25 they also operate F4H to remove the mark from EM1 which then remains at O until another meter pulse arrives. F5J and waveform WT cause F4H to erase the record from the time store, while F2C through gate G29 causes F4H to erase the mark from element EM2. In each of the next scans 1 is added to the time store. Assume that another pulse arrives before the time store is full. Then a mark is re-entered at EM1 and the timing store is cleared. The mark is also re-entered at EM2 and 1 is added to the existing record of the temporary fee section. The apparatus functions as before at the end of the pulse and if no further pulses occur, when the drum has made 8 revolutions so that element ET4 of the timing store carries a mark, transfer to the appropriate permanent store is initiated. At time ET4, F1A conducts and with pulse tt opens gate G36 to operate F6S. The binary pattern set up on EF1-3 is detected by F1 and in conjunction with pulses tf1-tf3 causes that section S, D, T or Q of F7 corresponding to 1, 2, 3 or 4 in the temporary store to operate and at the same time clears the temporary store. For single fees gate G32 fires section S at pulse tf1. For double fees G33 fires section D at pulse tf2 provided F7N was previously conducting, thus indicating that O was read from element EF1. For triple fees pulse tf2 fires section T which extinguishes section S. For quadruple fees pulse tf3 fires section Q. Pulses tf3 and t2 open gate G37 to restore F6 and F4. When the element preceding the first element in the single, double, triple and quadruple store is being read, pulse t2 in combination respectively with tf3, tdf, ttf, tqf causes the operation of gate G6, G7, G8 or G9, according to whether section S, D, T or Q of F7 is conducting, to operate F3F to add 1 to the appropriate store. A pulse te denoting the end of the track section resets F7 to N. If all the elements are 1 indicating full capacity then gates G11-G14 reset F3 to prevent adding 1 to the next store. Second embodiment. Instead of having all the information on one track, five tracks are used, one for timing and temporary store, the other four for single, double, triple and quadruple stores, the latter being displaced with respect to the former as shown in Figs. 21, 22. Reading and recording occur on diametrically opposite positions on the drum. Fee transfer thus takes place twice to ensure both halves of the track are modified. Trigger pairs F1-F7 function as in the first embodiment, additional pairs F8-F11 being provided for controlling reading and recording on the extra tracks. F8, Fig. 24, ensures that both halves of the permanent record tracks are modified. F8V is normally operated and permits the first transfer of the fee, while F8U is operated to make the second transfer and erase the recording in the temporary fee store. F9, Fig. 23, responds to the record on the particular permanent fee track being modified, W or X operating according to whether 1 or 0 is read. F10, Fig. 23, controls recording in the permanent fee tracks. F11 controls addition to the permanent record, L or M operating according to whether the record is to be reversed or unchanged. Operation. The track section on the first track corresponding to subscriber 1 appears at the reading head during position pulse P1. Registration in the timing and temporary store of one or more meter pulses takes place in the same manner as in the first embodiment. When 1 is read from element ET4 fee transfer is initiated by the operation of F6S which opens gate G15 to cause F4G to record 1 in an extra element EM2. Gate G24 causes O to be entered in element EM3 corresponding to EM2 in the first embodiment. In the example of a single metering pulse, 1 in element EF1 operates F7S. Coincidence of waveform WF, F8V, t2 and F3E opens gate G18 to cause F4G to record 1 on element EF1 while EF2, EF3 remain at O, i.e. the temporary record is unchanged. Gate G42 opens at pulse tf3 to operate F11L to control addition into the permanent record. The permanent fee stores then appear as seen in Fig. 21. F7S and waveform WA open gates G44, G45 to give access to the single storage track. If this track is previously clear, element SF1 operates F9X, which with F11L and pulse t2 opens G40 to cause F10Y to record 1 on element SF1. Gate G43 then resets F11 to F11M and the following elements SF2-SF12 are recorded unchanged. Pulse tm3 opens gate G28 to restore F7. At the next scan ET4 again operates F6S. The mark in element EM2 operates F8U. The information in the temporary store is again transferred to F7, but this time F8U opens gate G27 so that F4H clears the temporary store. F7S causes the modified permanent store to be read into F9 and repeated unchanged by F10 to the second half of the track. The omnibus claim of Specification 684,079 is acknowledged. Specification 746,672 also is referred to.