Patent GB-483578-A (GB)
Title: Improvements in or relating to record-controlled multiplying machines
IPC: G06F7/46
Filed: 1936-10-21
Abstract: 483,578. Statistical machines. WOOD, N. M. (International Business Machines Corporation) Oct. 21, 1936, No. 28672. [Class 106 (i)] A record-controlled multiplying-machine (for giving the product ŒC x ŒD) comprises two sign-detecting relays each adjusted according to whether the correlated factor is +ve or - ve, and a control device adjusted by the signdetecting relays to a +ve condition when both the relays are in their + ve or their - ve adjustment, and to a - ve condition when one relay is in + ve and the other in - ve adjustment. Further, a third term B may be added to, or subtracted from, the above product to give the result of the expression (ŒCxŒD)ŒB. The invention is described as applied to the machine described in Specification 405,031. In each of three columns related to the term B and factors C and D, a special hole is present if the corresponding term or factor is - ve. These columns are read by brushes 60, 70, 71, Fig. 1c, to energize, if holes are present, one or more of the sign-detecting relays 99, 72, 73 which, if energized, reverse their contacts 99a, 72a, 72b, 73b from the condition shown. In reading and multiplying two factors together, resetting the counters and punching the result, six machine cycles are used in which multiplication occurs in the fourth and fifth cycles. If the term B is to be added or subtracted, two more machine cycles are inserted before the above fourth cycle, during which two cycles the term B is transferred from the right-hand partial product counter RH to the left-hand partial product counter LH in true or complementary form and the counter RH is reset. A final, ninth, machine cycle is also added for re-setting the counter RH a second time after multiplication. The contacts 99a, 72a, &c. are shown in their " positive " condition. If factors C and D are both positive or both negative, relays 72, 73 are both unenergized or both energized respectively and contacts 72a and 73a are both unaffected or both reversed so that the circuit through them remains broken. Thus, even if contacts 99a are closed (term B +ve) the circuit is not completed through switch SP2 to energize a coil 62. Also, if factors C and D are both +ve (contacts 72b and 73b as shown) or both - ve (contacts 72b and 73b reversed) a series circuit is closed and if term B is -ve (contacts 99a reversed) the coil 62 is energized. Thus coil 62 determines whether addition or subtraction should occur. If B is + ve, coil 62 will also be energized over contacts 72a, 72b if one of C or D is negative. If, however, B is - ve and one of C or D is negative, the circuit is again broken through contacts 72b, 73b. If coil 62 is energized it reverses contacts 62b, Fig. 1a, and during the same machine cycle left-hand contacts S1 are closed and coil M closes contacts M1. A circuit 12, CC2, M1, 62b, S1, 36 is thus completed whereby the energized coil 36 causes term B to be transmitted from counter RH to counter LH. With the coil 62 energized, contacts 62c, Fig. 1b, are reversed so that the transmission is in complementary form. Coil 36 also closes its contacts 36b to energize, through emitter E, a magnet 37RH which, in known manner, resets the right-hand partial product counter RH in the next machine cycle. In this cycle multiplication is initiated over a circuit CC2, M1, the upper contacts 62b, contacts 32a and coils 33 as in the prior Specification. If, after multiplication and after the right-hand partial product has been entered into the left-hand counter LH, a complement on the latter counter is finally converted to a true amount, the highest wheel passes from 9 to 0 and closes contacts 69, Fig. 1c, which energize coil Y and magnet 67, the latter tripping the carry mechanism for the units to add the fugitive one. Energization of coil Y indicates that the result in counter LH is a true number. If coil 62 is energized, as above, it closes its contacts 62d, Fig. 1c, to energize a coil P which closes its contacts P1 to maintain itself through contacts CC5. These contacts maintain coil P energized for a short time after coil 62 becomes de-energized. Then a circuit 62d (upper), P2 (closed by coil P), 64 energizes a coil 64 which converts the amount in counter LH into its complement. If, however, the result in counter LH is a true number, coil Y is energized and opens its contacts Y1, deenergizing the coil 64. The reading-out mechanism LHRO, Fig. 1b, of the counter LH is connected by wires 52 and normally closed contacts 64c to punch magnets 53. If coil 64 is energized, contacts 64c are reversed and the complementary connections from wires 52 to contacts 64c cause the punching of holes representing the nines complement of the amount in counter LH, and since this amount is a complement (coil 64 energized), the holes punched will represent the true amount. If the final result of the expression (ŒC x ŒD)ŒB punched in the card bearing the factors and term is negative, a special hole is punched in a selected card column by a punch magnet 53 marked X. If the result of the product CD is +ve then the final result on counter LH is + ve if it is a true number and - ve if it is a complement, i.e. the special hole should be punched if coil 64 is energized. If, on the contrary, the product is -ve, a +ve final amount will be obtained as a complement and a - ve amount as a true amount. If one only of the factors C and D is - ve, contacts 72a or 73a, Fig. 1c, are reversed for a negative product, and a circuit is completed to energize coil Q which establishes a holding circuit for itself through its contacts Q1 during the punching operations. As the card previous to the one now being considered leaves the punching mechanism, the card ejector closes contacts 76 to energize a coil R, parallel to coil Q which closes its contacts RI to give a holding circuit. The action of the card carrying racks now opens contacts 76 and then 74 to de-energize coil Q, but coil R remains energized until punching on the present card is completed. Coil R closes contacts R2, Fig. 1b. If the product is + ve, coil R is not energized and the position of contacts 64e decides the recording of the special hole from magnet 53-X. Plug connections 79, 80 are made as shown. Assuming that. a complement has been obtained as the final result in the counter LH, relay 64 is energized and reverses contacts 64e so that a circuit 79, T2 (closed by coil T when brush 110 connects to the appropriate socket 50), R2 (lower), 64e energizes the punch magnet 53-X. For a negative product, coil R is energized and closes upper contacts R2. If the upper contacts 64e are closed (coil 64 not energized, i.e. the amount in counter LH is a true amount) a circuit is again closed to punch magnet 53-X. By opening switch 100, Fig. 1c, omitting certain plug connections, and raising switch SP1, the two factors may be multiplied together and the special hole punched if the product is negative. The machine may also obtain the sum or difference between two terms Band C. These terms are punched in the cards together with unity as the multiplier of term C. Further, by closing switch 66, Fig. 1c, to short-circuit the brush 60, all terms B may be treated as -ve.