Patent GB-709030-A (GB)
Title: Improvements in or relating to record card controlled calculating means
IPC: H03F1/36
Filed: 1951-12-11
Abstract: 709,030. Statistical apparatus. INTERNATIONAL BUSINESS MACHINES CORPORATION. Dec. 11, 1951 [Dec. 12, 1950], No. 28974/51. Class 106 (1) Apparatus according to the invention comprises a cyclically operating record card reading machine, including storage entry means, a cyclically operating storage unit group, the machine and the storage group having individual unsynchronized driving means, a calculating machine including means to store factors and means to compute results from the factors, including means to store the results, means controlled by the record card reading machine for reading factors into the factor storage means, for initiating a computing operation by the calculating machine, and for reading out results from the accumulator into the storage entry means, and means controlled by said storage unit group for reading results out of said storage entry means into storage units of said group. Fig. 1 shows the apparatus according to the invention, which comprises a tabulator T, a storage machine S and a calculator C. There is also shown a fourth machine S.P. which is a summary punch, but this machine is not an essential part of the invention which comprises the other three. It may therefore be assumed that the calculating machine C is directly connected to the tabulator by cables 2 and 3 the ends of each cable being strapped across within the summary punch. The tabulating machine is connected to the storage machine by a cable 4, there being no mechanical connection between the various machines. The tabulating machine moves as the primary programming means of the group and the means for entering numbers. This is a record card, controlled. machine of usual construction and well known in the art, and is controlled by perforated cards of the kind shown in Fig. 10. Each card has parallel columns of index positions. The first eleven index positions of a column are in ascending order, the 9 to 0 and X index positions. A single perforation in a column in one of the 9 to 0 positions denotes a digital value corresponding to that position. The cards are read at an upper brush station AB, Fig. 2, and one cycle later at a lower brush station LB. The cards being fed from a supply hopper 25 by a picker 26 in the usual manner. The card feed means is driven from the continually rotating shaft 12 through a clutch means actuated by an electromagnet CFM. Recording means are provided to print numbers being fed into the machine and intermediate or final results by means of type bars 52 of the known kind shown in Fig. 3. The type elements 52 bear the types for printing digits 9 to 0 in descending order, and the required type is selected by the print magnet PM energized by a timed impulse from a record card reading or from the accumulator of the calculator. Printing hammers 75 are tripped and strike the type elements to print the selected data in known manner. The printing operation is only carried out during desired cycles under control of a hole in a record card or some other signal. The operating means for the printing operation being under the control of a print clutch magnet PCM, Fig. 2. Means are provided in the tabulating machine to store temporarily numbers read out of the calculating machine, the numbers being then immediately transferred to the storage machine. In this way it is possible to ensure that the read-out from the calculator does not occur during calculation and it is possible to use a single read-out of the calculator for control of both printing and transfer to storage. Each storage entry unit comprises a set of eleven ratchet sectors such as 100, 100a, Fig. 7, mounted on a common shaft 101. In the normal position the ratchet sectors are pulled by springs in that their shoulders 109 bear upon the upper edge 110 of a bail cross bar. Each ratchet sector carries a contact 125 which passes over an actuator array of read-out contact bars 130 first in clockwise and then in counter clockwise direction. On the return stroke the contact 125 may be stopped in any position by a stop pawl 131 controlled by a stop magnet MG. There is a stop pawl and magnet for each sector. Each storage entry which will retain a setting as long as the bail remains latched and will be reset incident to the entry of a new number. Fig. 4 shows the auxiliary storage machine, of which there may be more than one. It comprises an arrangement of storage units identical to the storage entry units described above. These are arranged in the cabinet S in two banks. In each bank are two rows with four storage units in each row all driven by a common motor SM. The drive ratio is such that the storage unit cam shafts make approximately three cycles to two of the tabulating machines, but the individual drives are not synchronized. Electronic calculator.-The electronic calculator is described in Specification 673,759, and includes a multivibrator circuit producing a series of "A" pulses occurring at a rate of 50,000 per second and a series of " B " pulses occurring at the same rate, but 180 degrees out of phase with the "A" pulses. The pulses operate a primary timer circuit which is a series of trigger pairs interconnected in a ring circuit so that only one trigger will be on at any one time. The circuit is reset to a condition where the first trigger is on and when "A" pulses are applied the triggers are switched on in succession, each trigger being switched off as the next one is switched on. The primary timer is a ring of 23 triggers to produce pulses for gating circuits to transmit a definite number of "A" or " B " pulses to a circuit element, or to operate a circuit element. The calculator circuit comprises electronic counters, each consisting of a group of four triggers interconnected in biasing fashion. Several counters are combined with carry means to form an electronic accumulator. There may be any desired number of counters in the accumulator, for example four, to receive the results of calculations, which include addition, subtraction, multiplication and division. During the calculating cycle the progress is controlled by the internal circuits of the calculator, but the programme is set up during the read-in portion of the tabulating machine cycle, by card originated signals from the tabulating machine. Multiple storage machines.-The storage machines are constructed and have their circuits so arranged that a plurality of them may be connected in tandem arrangement. Figs. 18a and 18b show two parts of the circuit, only the selector relays for two of the eight storage units of each of the six banks being shown. Calculator sequence.-At 177 degrees of the second cycle of the tabulator the programme reset CB 116. Fig. 16d opens to remove -100 volts from wire C35 and allow the primary timer Fig. 16i to restore to step 1 and the programme timer, Fig. 16j, to reset to the home position. At 190 degrees CB 106 opens Fig. 16e denoting plus 40 volts from wire Cl connected to the grid of an inverter 1-6 M, Fig. 16i. The resulting reduction of voltage on this grid causes a rise in plate potential which is transmitted through a resistor to the left grid of the computer start trigger 1-10 F turning this trigger on. A negative impulse from the tapped lift plate resistor of this trigger is transmitted through a condenser to the right grid of a computer start stop trigger 1-5 L turning it on. Plus voltage from a tap on the right plate of the compute start stop trigger 1-5 L is transmitted to the grid G2 of a tube 1-5 K making this switch tube responsive to plus A pulses applied to its grid G1 from the "A" pulse generator diagrammatically indicated. These pulses cause the primary timer to step along at "A" pulse frequency as described in Specification 673,759. During the calculate sequence pieparation is made for reading out the accumulator into channel C, and storage entry 1. The number standing in the accumulator is a nine's complement, for example, 9994 representing 0005. This complement has to be read out of the accumulator in such a way that an output signal from any counter of the accumulator on passing from 9 to 0 will coincide with the corresponding digital index point of the machine into which the number is being transferred. For this reason it is necessary to use an inversion read-out in order to store true numbers in the tabulating machine, and this is done by adding groups of rapid pulse before each CB inpulse in order to step the counter bank one step for each CB impulse. The rapid impulses are controlled by a three stage straight binary 8 electronic timer, Fig. 16i 3-2 B, 3-2 C, 3-2 D. A single read-out of the accumulator serves for controlling the printing and the storing of the result. The signal to initiate read-out and re-set of the accumulator comes from the punching in the channel C control field, but in the same cycle an "X" hole in the special control field is read which causes the same output impulses from the accumulator which control the storage entry device to control the printing mechanism. Interlock circuits.-Since the storage unit banks are driven independently of the tabulating machine interlock circuits are necessary to take care of all possible phase relationships, which may arise, for example if the storage units tend to lag behind the tabulating machine the impulse to R 2118, Fig. 16b, is shifted to an earlier time giving more room for the creeping condition to operate without trouble. This is usually sufficient as the chances of a continuance of creeping action become less with each cycle. If, however, the creep continues the interlock means include means to force an idle cycle of the tabulating machine if necessary by latching up the card feed clutch for one cycle. The idle cycle of the tabulating machine completely removes the lateness of the storage machine which has been building up through many cycles. Although the rate of operation of the electronic calcu