Patent GB-856350-A (GB)
Title: Magnetic core store
IPC: G11C8/02
Filed: 1958-02-06
Abstract: 856,350. Circuits employing bi-stable magnetic elements. OLYMPIA WERKE A.G. Feb. 6, 1958 [March 18, 1957], No. 3910/58. Class 40 (9). [Also in Group XIX] Storage cores with any desired hysteresis loop are arranged in the manner of a matrix wth reading, writing and output windings allocated to all the cores, the reading and writing windings on each core being each connected in series with a rectifier, and each such series connection being directly connected between a row switching valve and a column switching valve. As shown, in Fig. 1, information is registered in a selected core by simultaneously energizing a lead in each of the groups 31a-33a and 11a-13a so that a column switching valve 31-33 and a section 111s-113s of a double-triode row switching valve 111-113 become conductive. A magnetizing circuit from source 100 is then established for a selected core over its writing winding and associated rectifier 41a. Readout by restoring the core to its initial state is carried out by the other section 111L-113L of a row switching valve which is rendered conductive by energizing a lead 111b-113b, magnetization of the core taking place over its writing winding and associated rectifier 41b so as to produce a pulse in an output winding (not shown). An arrangement for registering a binary word in a row of cores is shown in Fig. 5 in which the binary pulse input train is applied to one grid of column-switching tetrodes 31-34. The second grids of these valves and the grids of double triodes 111-116 in the row circuits are connected to separate energizing stages of ring counters 231-234 and 211-216, respectively, and a switch 200 determines the reading or writing operation. In use, clock pulses S step the ring counter 231-234 so that successive input pulses forming a binary word are registered in a matrix row, and the output at the end of each complete count feeds a pulse γ to the ring counter 211-216 so as to step this counter to the next row for a further binary word registration. A modified circuit is described, Fig. 7 (not shown), in which the row valves are controlled directly from an order issuing mechanism. A modification of the column-switching valve circuits providing re-registration after read-out is shown in Fig. 8 in which a tetrode valve 31a-34a and 31b-34b is associated with the column writing and reading leads 131a- 134a and 131b-134b, respectively. The reading operation is effected in each column in turn by a clock pulse S which controls a ring counter 231-234. As the count proceeds, each pair of valves such as 31a, 31b in a column circuit have their second grids energized. The clock pulses are also applied to the first grids of all the reading valves 31b-34b over a pulse halver 303 which suppresses the second half of each pulse. The reading operation therefore takes place, and if the selected core has its magnetic state reversed a pulse is developed in output winding 300 which triggers a monostable circuit 301. The pulse output of this circuit is applied to the first grids of all the writing valves 31a-34a during the second half of the clock pulse, so that the re-writing operation takes place. It is stated that transistors may replace the vacuum tubes described in the various embodiments. A constructional arrangement is also described, Figs. 10 and 10A, in which annular cores such as 56 together with associated rectifiers 56a, 56b, U-shaped wires 409a, 409b and resilient contacts 408 are located in apertures in a stack of insulating plates 401-405. The output winding 300a is threaded through the various cores and the U-shaped wires which constitute the reading and writing conductors are soldered to' conductors 431a, 431b etched on the insulating plates 402.