Patent GB-1048466-A (GB)
Title: Sense line capacitive balancing in word-organised memory arrays
IPC: G11C7/02
Filed: 1964-02-26
Abstract: 1,048,466. Circuits employing bi-stable magnetic elements. STANDARD TELEPHONES & CABLES Ltd. Feb. 26, 1964 [Feb. 27, 1963], No. 7970/64. Heading H3B. The select wires and sense wires of a wordorganized memory array are arranged so that some of the signals capacitively coupled from the select wires to the sense wires are in antiphase with the others of such signals thus reducing spurious signals in the sense wires due to pulses on the select wires. The wordorganized memory is of the form in which magnetic cores are organized into word groups which are organized into planar sub-sets, Figs. 1, 2 (not shown), there being an individual word read selection wire and an individual word write selection wire coupled to each word group. Digit selection wires and sense wires are arranged transversely to the word wires. In order to compensate for capacitance coupling between the sense and digit wires the digit 10 and sense wires 20 are arranged as shown in Fig. 4. The A and B half segments of the sense wire both enter successive planes P 1 , P 2  at one end thereof and emerge from the last two planes P 63 , P 64  at the other end where they connect to mid-point 21. The A sub-segments are coupled in sequence to the odd-numbered planes and two B sub-segments are coupled in sequence to the even-numbered planes. As shown by the arrows 15 complete magnetic cancellation is achieved throughout the sense wire. When a digit signal excitation source is connected across terminals 25, 26 the signal on the digit wire will be capacitively coupled to ground at 24 via the distributed capacitance between each pair of corresponding sense and digit wire sub-segments in planes 1 to 64 and in addition this signal will be progressively attenuated. Since the sequence of coupling of sub-segments of the sense wire to successive core planes is A, B, A, B . . . the difference between the sums of the signals capacitively coupled to the A and B subsegments will be small. If the sequence of the coupling is A, B, A, B. . . through the first 32 planes and B, A, B, A . . . through the remaining 32 planes then the difference between to the sums is zero, Fig. 5 (not shown). Capacitive coupling also exists between signals applied to word select wires and sense wires in a word-organized array wherein all of the word selection wires associated with a planar sub-set of word groups in the array are connected in multiple at one side of the array to a corresponding selection switch, and the word selection wires associated with word groups of cores in corresponding word positions in different planes are connected in multiple at the other side of the array, Fig. 6 (not shown). In order to compensate for this the word selection wires connected in multiple to any one of the switches are so selected that the sub-set of wires defined thereby comprises an even distribution of wires relative to the crossing sub-segments of each sense wire disposed as in Fig. 4 or Fig. 5, Fig. 7 (not shown). The extraneous signal capacitively coupled to the sense wire via any sub-set of multipled selection wires is balanced between the A and B segments of the sense wire. Figs. 8, 9 (not shown) provide wiring arrangements providing further cancellation. Where an individual selection wire is coupled to each storage word group and each individual wire is controlled with a corresponding individual switch element, Fig. 10 (not shown), the relative positions of the word selection wires are systematically rearranged, Fig. 11 (not shown).