Patent GB-1011780-A (GB)
Abstract: 1,011,780. Accounting machines; counters; electric calculating apparatus. INTERNATIONAL BUSINESS MACHINES CORPORATION. Nov. 16, 1962 [Nov. 17, 1961], No. 43368/62. Headings G4A, G4D and G4M. General.-A record-card-controlled accounting machine includes an input hopper 2001, Fig. 26, two sensing stations ABS1, ABS2, and a card deflector 2101 which directs the sensed cards either to an output pocket 2120, or through a punching station SE to an output pocket 2620. The machine also includes a second input hopper 2501 from which cards may be fed to punching station SE and output pocket 2620. Data sensed from the cards are entered into mechanical storage devices of known type or into electro-mechanical counters which perform the operation of addition, subfraction and multiplication. Card sensing is by a known type of pin senser which closes contacts when a hole is present in the card. Interstage positions are used on the cards, and each reciprocating arm 2041 carries two staggered pins for sensing adjacent columns. The cards are advanced row-by-row and stepby-step past the row of sensing pins, and each data-representing pulse from the sensing station may be converted to a train of pulses by camcontrolled contacts for entry into the counters. Provision is also made for entering data directly into selected storage devices or an output printer from the sensing stations. Programming.-A chain of relays which are energized. in sequence in successive machine cycles produce control pulses to initiate various operations, not described in detail. One or more of the programme steps may be by-passed by plug-board connections. The feeding of cards from the two input hoppers and the operation of the printing and punching mechanisms are controlled by the selective energization of respective clutches in the driving mechanism. Card detection.-Switches associated with the input hoppers and output pockets stop the machine when an input hopper becomes empty or an output pocket is filled. The presence of a card in a sensing station is also detected by using the first and last-but-one sensing pins in the row to detect the leading edge of the cards, the machine being stopped if a card is not present in a sensing station at the correct time in a machine cycle, or if the card is misaligned. Counters.-Two types are employed. In the type shown in Fig. 37 a ratchet-wheel Z12 is rotated by a pawl Z19 in response to pulses supplied to an electromagnet (not shown). Shaft Z11 carries a brush Z18 which makes contact with one of ten contacts Z28 to provide an electrical indication of the count stored. Shaft Z11 also carries a pair of cams Z15, Z16, the first of which, Z16, maintains a pair of contacts closed so long as the count is not more than nine, and the second of which, Z15, closes a pair of contacts to provide a carry pulse to the next higher order counter when ten pulses have been received. Contact arm Z25 is latched in the operated position by an arm Z21 until it is released by a further electromagnet (not shown). In the second type of counter employed, pulses are supplied to an electromagnet Z35, Fig. 39, which pulls a shaft Z30 downwards against the action of a spring Z37. Shaft Z30 carries a pin Z31 which engages a tooth on a fixed flange Z32, Fig. 40, and rotates shaft Z30. Release of electromagnet Z35 at the end of a pulse causes shaft Z30 to rise, and pin Z31 engages a tooth in a second flange Z33 to rotate shaft Z30 by a further amount. A contact arm Z38, Fig. 39, carried by shaft Z30 may be brought into engagement with one of a series of contacts Z39 by energizing a further electromagnet to provide electrical read-out. Addition and subtraction.-Stepping pulses are supplied to the various decimal order counters from cam-operated contacts, the number of pulses supplied depending on the values sensed from the card. Towards the end of a machine cycle, any closed carry contacts on the counters cause carry pulses to be applied to the next higher order counter. Subtraction is performed by addition of the nine's complement of the value to be subtracted, e.g. if the value 0012 is stored and 5 is to be subtracted therefrom, the three highest order counters will receive nine stepping pulses and the remaining counter 4. At carry time the tens counter will cause carry pulses to advance the hundreds and thousands counters to zero, and the carry pulse from the thousands counter is fed back to the units counter to advance it from 6 to 7. Multiplication.-The multiplier is entered in a particular group of counters, the multiplicand is entered in any other counter group, and the product may appear in any other desired counter group. Multiplication is effected by repeated addition of the multiplicand. Provided the multiplier has no digit as great as 6, the multiplicand is repeatedly added to the product counter group, the units digit of the multiplier being reduced by one each time until it is zero. The process is repeated for the remaining multiplier digits, the multiplicand being shifted to the left before transfer to the product counter. If a multiplier digit is 6 or more, the multiplicand is shifted an extra place to the left during the first transfer to the product counter, effectively multiplying by 10 in that order, and in successive cycles the multiplicand is subtracted after the appropriate shift left, the corresponding digit of the multiplier being increased by one each time until it is zero.