Patent GB-800587-A (GB)
Title: Improvements in or relating to dynamic memory device using electrical pulses
IPC: G11C21/00
Filed: 1956-06-18
Abstract: 800,587. Electric digital-data-storage apparatus. COMPANHIA PORTUGUESA RADIO MARCONI. June 18, 1956 [June 20, 1955], No. 18761/56. Class 106 (1). An electric data-storage system comprises means for modulating pulses in accordance with information to be stored, means for marking the first pulse in any sequence and storing the pulses in a circulating system, means for preserving the waveforms of the stored pulses, switching means for releasing the stored pulse train in the correct sequence when triggered by an external signal, and means for demodulating the pulse sequence. As shown in Fig. 1, information in the form of a wave 10 is sampled by a device 11 which gives out a corresponding series of short, amplitudemodulated pulses. These are fed to a circulating store 13 comprising a regenerating device 14. The store has a delay period which is less than the pulse repetition period and such that after the first pulse has circulated one or more times the second pulse is entered closely behind it, the third pulse being packed behind that, and so on. The process is reversed during reading out, but not necessarily to space the output pulses by the same period as before A demodulator 18 produces an output waveform 19 equivalent to the input wave 10. Instead of a single delay loop a series of circulating delay devices may be employed. These may have progressively greater capacity. Thus, the first could be an electromagnetic regenerative delay loop of small capacity, and the final one could be a large-capacity rotating magnetic drum or magnetic tape. Such a system is shown diagrammatically in Fig. 2. Amplitude-modulated pulses from a modulator 21 are passed by a switch 22 to a first circulating-loop store 24 and are packed close together in the manner indicated in Fig. 1 until a " full " or " busy " signal on a line 34A changes over the switch 22 so as to send further pulses to a similar store A2. The pulses passing into A2 are counted by a device CA and when the maximum is reached the contents of A2 pass through a second switch SA to a greater-capacity store B1. After a number of such entries into B1 a " busy " signal on line 34B changes the switch SA to direct further outputs from A2 to B2, and so on. If, ultimately, the store N2 becomes filled, the counter CN operates switch SN to activate an alarm device 32. The release process is initiated by a signal at terminal 28 which opens a gate 25A to allow stored information to pass from A1 to a demodulator 26. When the last pulse is leaving A1 a " transfer " signal on line 36B opens the next gate 25B to allow the next block of information stored in B1 to pass into A1. Further transfer signals call up subsequent blocks until B1 is emptied and the next gate 25C is opened to admit larger packages from C1, and so on. When the " transfer " signal finds the next higher store (e.g. C1) empty the adjacent switch 31 is adjusted to pass the contents of the upper store (C2) into the empty store (C1). A simple embodiment (Fig. 3, not shown) is described in more detail in the Specification.