GB765664A - Improvements in or relating to electrical intelligence storage equipment - Google Patents

Abstract

765,664. Electric digital-data-storage apparatus. STANDARD TELEPHONES & CABLES, Ltd. March 20, 1953, No. 7831/53. Class 106(1). Equipment for storing intelligence comprises a number of stores with which are associated recording and reading means, each store being available to any one of a number of user equipments, and a control circuit associated with the recording and reading means and including means responsive to an electrical condition in. dicating that one of the user equipments requires a store whereby a free store is temporarily allocated to that user equipment and the allocation maintained throughout a plurality of examinations of the store by the reading means. The invention is applied to an intelligence storage system of the type described in Specifications 744,352, 744,356, 744,357 and 744,358. In a first embodiment each of a plurality of tracks on a magnetic drum are divided into a number of lengths, and two lengths 180 degrees apart form a single storage section. While a read/record head is reading one length, a similar head diametrically opposite is recording upon the other length. However, by employing a compound reading/recording circuit, a single length of track could be used. In addition to storage tracks ST on a drum MD, Fig. 1, a clock pulse track ET and a track MT giving pulses marking the beginning of each length or section are provided. The former operates a counter EC, advancing it by the number of digital spaces in a section (e.g. 48) and, via pulse former PF and delay devices D1, D2, provides three staggered pulses t1, t2, t3 during each clock pulse period: the latter serves to return the counter EC to its initial state at the beginning of each section. Each storage section serves a plurality (e.g. ten) input or " caller " lines T1, T2, &c. which are identified with digit places 2 to 11, respectively, in each section. Fig. 9 is a time chart indicating the functions of the 48 digital spaces in a complete storage section. Associated with channel circuits CC1, CC2, CC3 between the incoming trunks T1, T2, T3 and the outgoing trunks TO1, TO2, TO3 is an electronic scanning circuit SCB which hunts over the channels in search of a channel needing a store for the regeneration of a series of digits. It is connected to equipment RSB which controls reading, recording, and insertion and extraction of information to and from the store. Receipt of first digit. A scale of ten. counter or register (F14, not shown) is stepped on by pulses from the clock track during the passage of digit places 2 to 11 before the read/write head. When a " calling " condition occurs on one of the associated lines (say, line " 4 "), the register is stopped at the corresponding stage (digit place 5). The calling condition is then disabled (to avoid " seizure " of successive stores), and an appropriately positioned auxiliary head, operating at digit time 31, as shown in Fig. 9, records a positive " busy " signal in digit place " 1 " of the store. At the end of the first scanning of this store a positive recording at digit place 48 zeroizes the control circuit in readiness for control of the next storage section. After 180 degrees rotation, the store being considered again passes a read/record head. The signal in the first position is read and rerecorded (see " PN2," Fig. 9); the signal in digit place 5 stops the register in its fourth position, and this signal and the others are detected and re-recorded. This process is repeated at each subsequent scanning and the number of excursions are counted and recorded in binary form in digit places 15 to 19. The counting is performed-as in the cases referred to-by reading the recorded binary elements and reversing all up to and including the first binary " O," after which re-recording continues without any change. When the first digit impulse is received on the marked " caller " line, a mark is recorded at digit place 32 in the section D1 allocated for recording in binary form the first digit from the seized " caller " line; the second, third and fourth digits are later recorded in sections D2, D3 and D4 respectively. Each digit impulse lasts for several excursions of the storage section, the actual number of such excursions being counted in the section R. If, due to a fault in the system, the impulse should persist beyond a certain maximum time the process of counting brings a mark into digit place 19 which causes forced release of the circuit. Normally, however, when the impulse ends, a mark is recorded in digit place 14, the count in digit places 15 to 19 is deleted and then recommences to count the excusions until the second impulse begins. Each subsequent impulse increases the value of the binary number in D1 by one. The completion of a digit is determined by detecting the length of pause between impulses. If the counting in R reaches digit place 17 it is assumed that a digit has been completed; marks are recorded in places 20 and 21. and the recording of subsequent impulses takes place in the next digit position (D2). Retransmission of first digit. The completion of the recording to the first digit causes it to be re-recorded in the form of its complement, and retransmission commences. As each impulse .is sent " 1 " is added to the complement in D 1 so that when all the elements in D1 are " mark " the digit will have been completely retransmitted. Each regenerated impulse starts at digit place 48 and lasts for four excursions which are counted in section S (digit places 25 to 30). After a digit has been completely retransmitted a pause of at least 36 excursions is timed by counting in Section S. During the interdigital pause other digits can be received and stored. General. The routing of digits to their places on the section is controlled by counters in the control circuit in accordance with intelligence read off the track. One counter routes received digits. to the appropriate portions of the store, stepping at the end of each digit, while a second,counter is used to determine whether retransmission can occur, and a third routes the digits out. The counters are set to positions appropriate to the store which is being scanned by intelligence read from that section. When all the digits have been received and retransmitted, the marks in digit places 1 and 5 are not re-recorded and therefore the store is again available for seizure by any of the ten associated " caller " channels. The circuits for performing the functions outlined above are built up from rectifier gates such as G120, G124, Fig. 13, cold-cathode tube flip-flops such as F8, and counters or registers such as C2 Fig. 14 (not shown). In a second embodiment, a matrix of magnetic cores (Fig. 16, not shown) takes the place of each magnetic drum storage, and in a third embodiment a ferro-electric matrix is used. Specifications 692,415, 713,902, [Group XL (c)], 765,072, 765,665, [Group XXXIX], and 765,666 also are referred to.