Patent GB-653312-A (GB)
Title: Improvements in or relating to calculating machines
Inventor: BALDWIN RICHARD EVEREST
IPC: G06F7/498
Filed: 1947-03-25
Abstract: 653,312. Statistical apparatus; calculating apparatus. POWERS-SAMAS ACCOUNTING MACHINES, Ltd. March 25, 1947, No. 8156. [Class 106 (i)] [Also in Groups VIII and XL (b)] A multiplying machine comprises multiplier and multiplicand registers each including, for each denomination or sub-denomination, a group of thermionic valves equal in number to the radix of the denomination or sub-denomination and being so coupled that, when any one valve is in a predetermined electrical state (i.e. conducting or non-conducting), all the other valves of the group are in the opposite state, factor-entering apparatus, means which when the factors have been entered tends to apply pulses to the grids of the valves, and selection means under the control of the registering valves to permit the application of pulses only to those valves which, in the multiplier and multiplicand registers respectively, represent half and double the values already registered so as to cause these valves to assume or maintain the predetermined registering state, the machine also including means for entering the value registered in the multiplicand register into a product register, which means are rendered effective, whenever the amount registered in the multiplier register is odd, under the control of the valves of the lowest multiplier sub-denomination, which is of binary form. General. The multipliers and multiplicands are entered into their respective registers from punched record-cards and each product, which is formed by successively halving the multiplier and doubling the multiplicand and summing the multiplicands corresponding to fractions of the multiplier that are odd, is punched automatically into the corresponding card. The machine is adapted for the British monetary system. Specification 653,313, [Group XL (b)], is referred to. Card feed. Each card is ejected in turn from a magazine 20, Fig. 7, by a picker 21 and is passed, a long edge leading, between rollers 36, where it is sensed, and rollers 38 to a magazine 49. Stops 37 and 39 hold the card stationary during multiplication and punching respectively and are operated, as is the picker 21, by cams on a shaft 30 rotated by a motor-driven mainshaft. According to the Provisional Specification, the card may be moved under control of pickers and stops, first with a long edge leading, then in a perpendicular direction through the sensing mechanism and finally in an opposite direction to the first through the punching mechanism. Sensing - mechanism. Each card passes beneath a plate 57, Fig. 7, which has two groups of eighteen apertures for the multiplier and multiplicand fields of the cards respectively Any number of these apertures may be shielded to limit the fields. The apertures in each group are staggered and the distance between the extreme holes in each group in the direction of card travel corresponds to the distance between adjacent rows of holes in the punched card. The groups of apertures are respectively scanned by beams of light formed by lenses mounted circumferentially on rotating discs 58, 59, Figs. 2 and 7, and originating from adjustably-mounted lamps 50, 51. The discs 58, 59 are driven, through gearing from the main-shaft at such a speed that as the beam from one lens completes its scanning of one row of a card, so the beam from the next lens begins to scan the next row. Light passing through an aperture in the plate 57 and a hole in a card is reflected to one of a pair of photo-electric cells (not shown) to produce a pulse at a time corresponding to the digit of the multiplier or multiplicand represented by the hole in the card. According to the Provisional Specification, the card columns may be scanned by light reflected from rotating mirrors, any light passing through a hole in a card being focussed by a lens-system on to a single photo-electric cell. Multiplier and multiplicand registers. Factorentering apparatus. The decimal denominations of the multiplier and the units-of-shillings and pounds denominations of the multiplicand are each divided into a lower binary subdenomination and an upper quinary subdenomination. The pence denomination of the multiplicand is divided into quaternary and quinary sub-denominations while the quaternary farthings and binary tens-of-shillings denominations are not sub-divided. Each of the multiplier and multiplicand registers comprises a ring of triode valves for each subdenomination, e.g. the multiplier units binary and quinary rings UB0-UB1 and UQ0-UQ4, Fig. 11E. The grid of each valve is connected through resistances 121 to the anodes of the other valves in the same ring so that, when any valve is in the registering (non-conducting) state, the other valves will be conducting. When a negative pulse is applied to the grid of a conducting valve, the valve is biassed beyond cut-off to assume the registering state and the consequent rise in its anode potential raises the grid potential of the previously registering valve causing it to conduct. These registering negative pulses are derived from the photo-electric cells 71, Fig. 11A (one only is shown), are amplified, and each is applied to the appropriate registering valve or valves by a pair of distributers 80, 80a and a similar pair (not shown), the brushes of which are rotated by the main shaft. The distributers 80, 80a together distribute the pulses to the binary sub-denominations of the multiplier and multiplicand registers and to the pence-quaternary sub-denomination of the multiplicand register, and are respectively rendered active during the sensing of the upper and lower halves of a card by contacts 90, 90a on a drum 91 on the shaft 30, which contacts engage brushes connecting the distributer brushes 82, 82a with the output lead 88 of the photo-electric-cell amplifier. The other two distributers are similarly rendered effective during the sensing of the upper and lower halves of a card respectively and together distribute the pulses to the quinary sub-denominations of the multiplier and multiplicand registers and to the pence ternary sub-denomination and farthings denomination of the multiplicand register. The distributer contacts are appropriately connected in groups to leads, such as 100u and 113b, which are connected to the grids of the associated registering valves through a removable and adjustable distribution panel 303, Fig. 2. According to the Provisional Specification, two distributers only are used, each being connected to the amplifier output lead 88 during the sensing of the whole of each card. Multiplication. The halving of the multiplier is performed by means of " attendant " valves, one or two such valves being associated with each registering valve. The grids of the attendant valves, e.g. UB1A1 and UB1A2 for the binary registering valve UB1 and UQ3A for the quinary registering valve UQ3, are connected through resistances 131 to the anodes of controlling valves in the two next higher subdenominations in the case of the binary attendant valves and in the same and next higher sub-denominations in the case of the quinary attendant valves. The controlling valves are so chosen that when a number is registered, the high anode potentials of the registering valves raise the grid-potentials of one attendant valve for each of the registering valves representing half that number to a point just below cut-off. A positive pulse applied from a lead 136 through condensers 134 to the grids of the attendant valves will then cause those just below cut-off to conduct, the ensuing decrease in their anode potentials acting through resistances 126 to lower the grid potentials of those registering valves representing half the multiplier so that they assume the  registering state. Doubling of the multiplicand  is performed in an analogous manner by means  of attendant valves, e.g. DT2A1 and DT2A2,  Fig. 111, for the valve DT2 of the pence ternary ring, the grids of which are connected to controlling valves in the same and/or lower subdenominations. However, for speed of operation, the doubling pulses are applied first through the lead 213a to the pence and farthings denominations, then through a lead 222b to the units-of-shillings denomination, then to the tens-of-shillings and units-of-pounds denominations and so on. Therefore, as octupling may be taking place in the lowest group while quadrupling and doubling are occurring in higher groups, any transfer from one group to another must be registered until the higher group has been doubled as many times as the lower had been at the time of the transferregistration. Thus in each group, valves, e.g. SS1, SS2, of an Eccles-Jordan trigger circuit, have their grids connected respectively through resistances 180, 185 to the anodes of those registering valves of the lower sub-denominations representing numbers which when doubled would or would not give rise to a transfer. The anodes of the valves SS1, SS2 are respectively connected through resistances 188 to the grids of the binary attendant valves SB0A, SB1A of the next higher sub-denomination. The transfer-registering pairs are re-set prior to each fresh doubling operation in the group to which they apply by the doubling pulse for the next lower group or, in the case of the lowest group, by the halving pulse. The halving and doubling pulses are applied respectively to the leads 136, Fig. 11C, and to the leads 213a, 213b ... , which are connected to the leads such as 222b ... of the multiplicand groups, by brushes 138, on the main shaft 31 which intermittently connect the leads 136 and 213a, 213b ... to leads 139 connected to a positive line PL, during that part of a machine operation allotted to the multiplication, by a contact drum 141a on the shaft 30. When a multiplier, or one of the values obtained by successively halving a multiplier, is odd, the amount registered in the multiplicand register is entered into a product register comprising a