GB809680A - Improvements in and relating to electrical systems for sorting messages - Google Patents

Abstract

809,680. Sorting digital data. STANDARD TELEPHONES & CABLES Ltd. (Laboratoire Centrale de Telecommunications S.A.). March 1, 1956, No. 6415/56. Class 106 (1). In an electrical system for sorting recorded messages each including an identification destination-determining portion, the messages are read sequentially and the identification portion of a message is stored in a temporary store co-operating with identification equipment so as to select a corresponding individual recording device to which is routed via the temporary store part of the message to be rerecorded. In the system described, groups of characters, relating, e.g. to telephone calls, are read from a magnetic tape by a device L, Fig. 1, and each group is routed via T, in accordance with the value of an identification character, to one of ten recording devices E1 . . . En ... Eo. The characters may be recorded on 5 parallel tracks on the tape in a 5-unit combination code, and read in succession by heads TL1-TL5, Fig. 5, which supply impulses via amplifiers to bistable double triode flip-flops F1-F5 forming a temporary store for the characters. An impulse from any head is applied also via decoupling rectifiers and an amplifier to a delay line LR having output taps which provide timing impulses R1-R5 the last of which resets all the flip-flops. Each group begins with a distinctive preparatory character which enables a flip-flop F6 (not shown) to be operated whereby when the following identification character (one of the digits 0-9) is set up on F1-F5, one of ten electronic gates such as G12 (for digit 2), Fig. 7c, passes impulse R1 to a corresponding flip-flop F12 which causes an associated tape-recording device to be selected. The subsequent settings of F1-F5 are passed by further gates (Fig. 9, not shown), to the 5 recording heads of the selected device, the selected flip-flop such as F12 remaining set until a signal G1 is obtained in response to the preparatory character of the following group. Since the identification digits used for selection are not re-recorded, if the tapes from the ten recording devices are introduced into the reading device L, a further sorting may be effected in accordance with a subsequent identification digit in each group. A 4-stage sorting process is described involving 4-digit identification numbers, e.g. calling subscriber numbers for a telephone accounting system. Reference is made to ferro-electric as well as magnetic recording and to drums as well as tapes.