Patent GB-786031-A (GB)
Title: Improvements relating to the sorting of signals recorded on a magnetisable signal carrier
IPC: G06F7/24
Filed: 1950-06-23
Abstract: 786,031. Sorting digital data. DIRKS, G. June 23, 1950 [Oct. 1, 1948], No. 37212/54. Divided out of 786,021. Class 106 (1). A sorting device comprises a carrier for signals to be sorted, means for sensing the signals, a second carrier with means for recording thereon signals derived from the first carrier, and step-by-step feeding means for the carriers which may be selectively disabled. In the described embodiment data is recorded magnetically on a tape 1 in the rows and columns of separate areas called " unities," so that the tape is equivalent to a continuous stream of record cards. Sorting is performed by repeatedly scanning through the tape, selecting at each run through certain unities which are reproduced on a second tape 2. This second tape is only fed forward when data has been recorded on it; eventually it contains all the data from the first tape arranged in the desired order. Fig. 1 shows the two tapes 1 and 2 between which two boxes 4 and 7, containing magnetic reading and recording heads 18<SP>0-e</SP> and 19<SP>0-e</SP>, and tape-feeding levers 13 and 16, respectively, are reciprocated back and forth a distance equivalent to one unity by mechanism not shown. During the movement indicated by arrow 8 the rows of the unity in position on tape 1 are sensed by the reading heads, the tape being held stationary during this period by stop teeth 5. On the return movement, indicated by arrow 9, the levers 13 and 16 in the second box are adapted to engage slots in the tapes to feed them along a distance of one unity, the stop teeth 5 being lifted clear during this movement. The feeding of either or both tapes can be disabled, however, by energization of magnets 14 and/or 17. During each run through of the tape 1 a selected single element is examined to determine whether or not the information in that unity shall be transferred to the second tape 2. Thus, in Fig. 3, a stepping switch element 31 completes a connection from the reading head of the " zero " row to amplifiers 30, 32 while a switch element 36 is closed at a position corresponding to the selected column in a commutator arrangement comprising a rotating one-toothed member 34 which provides momentary inductive coupling between successive pairs of coils during each cycle corresponding to the complete sensing of a unity. If a " mark " is detected at the selected point a gas tube 35 fires and gates the rest of the information from the reading heads through to the recording heads for reproduction on the second tape. Both tapes are then fed forward by one unity. If no mark is detected at the selected point no transfer of information takes place and a magnet 17 is energized, withholding the feeding lever 16 from engagement with the tape 2 during the feeding movement. In a modified arrangement information is transferred to the second tape each time, but is erased when no " mark " is detected at the selected element. In another form the reading heads for examining the control element operate one unity ahead of the main reading heads and the detection of a mark may be recorded magnetically at a convenient control point on the tape, to be detected at an appropriate time by a further reading head. Instead of selecting one of a large number of coils for activation by the rotating one-toothed member 34, Fig. 3, one set of coils may be adjustable in an annular channel and may be set into any desired column position against a graduated scale. In another embodiment a cathode-ray tube distributer is employed in place of the inductive commutator. The rotary scanning of the C.R.T. beam over a ring of target electrodes is synchronized with the tape reading by controlling the scanning voltages to the tube deflector plates from signals recorded on the tape and picked up by a separate reading head. Specification 786,034 also is referred to.