Patent GB-744352-A (GB)
Title: Improvements in or relating to intelligence storage equipment
Inventor: WRIGHT ESMOND PHILIP GOODWIN
IPC: G11C11/22
Filed: 1951-05-23
Abstract: 744,352. Digital electric calculating apparatus. STANDARD TELEPHONES & CABLES, Ltd. May 21, 1952 [May 23, 1951], No. 12060/51. Class 106 (1). Equipment for the storage of intelligence comprises a number of separate stores each individually allocated to a particular one of a number of items of intelligence, means for reading the items in succession, means for restoring the items in turn in the same order in which they were read and in stores individually allocated to them, and means for altering any item of intelligence during a transfer operation between the reading and the restoring means. In one embodiment a magnetic recording head STH, Fig. 1, makes longitudinal N-S or S-N recordings representing binary digits, on one track of a magnetic drum (which may be of nickelplated brass). A reading head RDH, arranged diametrically opposite the recording head, picks up the recorded signals and, after amplification, these cause a flip-flop RDF to be set in accordance with the binary digits read out. The information may be returned unmodified to the recording head STH via a gate STG, may be read out via a gate OTG, or may be modified under the control of a flip-flop ACF before rerecording or reading out. The information on a single track is divided into a plurality of sections, a marker track MKT common to all the storage tracks of a drum indicating the starting positions for each of the sections. An element track ELT supplies groups of pulses t 1 , t 2 , t 3  at the required frequency for the recording of binary digits. The output from a marker read head MRH provides pulses to operate a position counter PC, the outputs P1 ... PN of which can be used to scan in turn input leads CL1 ... CLN to a condition flip-flop CNF. Thus, it may be required, for instance, to add 1 to a value read by the read head RDH whenever a condition signal appears on the related control lead CL-, passing on the previous value unchanged if the condition signal is absent. The condition flipflop CNF, shown in more detail in Fig. 3, is normally in the C-tube -conducting state; the D tube is fired when the position counter output scans a lead CL- which is subject to a condition signal. The first element space in each section is used to indicate whether or not an addition has been made in response to the conditioning of a lead CL-. If not, the reading flip-flop AB assumes the B-tube-conducting position and a pulse is gated to fire tube F at the t 2  pulse time. The condition of the flip-flop EF determines whether the resultant flip-flop GH assumes the same state as the reading flip-flop AB (i.e. when tube E is conducting), or the reverse state (tube F conducting). The addition of one digit is performed by recording the reverse of each binary digit received up to and including the first zero and thereafter recording the digits unchanged. An RC network at the cathode of tube F and connected to the gate at the trigger element of tube E provides a suitable delay. As the information is read off and re-recorded 180 degrees round the track, the newly modified data will, in turn, pass under the recording head and the appropriate lead CL- will, normally, still be conditioned at this time. However, the first element space will now contain a significant digit so that tube A of the reading flip-flop AB will be fired and the flip-flop CD will remain in the C-tube-conducting condition. Accordingly, the addition control flip-flop remains in the E-tube-conducting condition and the binary digits are re-recorded without modification. As alternatives to the magnetic drum storage, systems for storing information employing a mercury delay line (Fig. 13, not shown) and a cathode-ray memory tube (Fig. 14, not shown) but with similar forms of external circuit, are also described. In a more detailed embodiment the invention is applied to a telephone message registration system in which the numbers of calls made by subscribers are registered on magnetic drums, and means are provided for extracting and printing this information. A binary-decimal converter for use when reading out from the system is described in Specification 744,400. The converter described in Specification 711,561 also is referred to. Means are described for translating the decimal result into a five-unit teleprinter code, utilizing a rectifier network (Fig. 9, not shown), and registering the code for each translated digit on groups of flip-flops (Fig. 10, not shown); these registering flip-flops are scanned under the control of a 5 kc/sec. pulse source so as to form a series-mode telegraph-coded signal for transmission to a teleprinter. Specifications 693,424, 732,341, 744,356, 744,357 and 744,358 are referred to.