Patent GB-786050-A (GB)
Title: Improvements in or relating to electric calculators
IPC: G06F7/38
Filed: 1950-06-23
Abstract: 786,050. Digital electric calculating-apparatus. DIRKS, G. June 23, 1950 [Oct. 1, 1948], No. 37232/54. Divided out of 786,021. Class 106 (1). In an assemblage of magnetizable elements with two sets of electrical conductors magnetically linked thereto, each conductor is linked to a multiplicity of elements and each element is linked to only one conductor of each set, no two of the elements linked to any conductor of one set being linked to the same conductor of the other set; current is passed along selected conductors of the two sets so as to set up magnetic flux to determine the magnetic state of the elements linked therewith, and means is provided for detecting that or those elements which have a particular magnetic state. In an arrangement for performing addition a digit of one of the numbers to be added is picked up from a magnetic tape a by a head 311 and, after amplification, fed to series-connected windings 304<SP>0</SP> ... 304<SP>9</SP> on U-shaped members such as those shown in Fig. 12. A corresponding voltage is induced in the winding on the other arm of a U-shaped member 304a only if a tooth 304<SP>0</SP>b is directly opposite the open end of the U-core. The series of U-shaped members and the teeth 304<SP>0</SP>b ... 304<SP>9</SP>b have a Vernier-like relationship so that only one U-core is operative at a time and, since the teeth move in synchronism with the tape a, the selected core corresponds in value to the digit picked up by the head 31<SP>1</SP>. The voltage surge in the selected secondary winding 305 fires an associated gas tube 95 and thus supplies energizing current to a column of windings such as 268<SP>0</SP> ... 268<SP>9</SP> representing the sensed digit. A digit of the other number to be added is set up-by means not described-by firing one of a series of gas tubes 244<SP>0</SP> ... 244<SP>9</SP>, and this supplies energizing current to horizontal windings such as 270<SP>0</SP> ... 270<SP>9</SP>, representing the second digit. The cores carrying windings supplied from the tubes 95<SP>0</SP> ... 95<SP>9</SP> and 244<SP>0</SP> ... 244<SP>9</SP> also have bias windings (not shown) which oppose the effect of energizing the tube-controlled windings. The bias is overcome, however, on the core selected by energization of both the column and row windings, and as a tooth passes this core a voltage is induced in the secondary winding which fires one of a series of tubes 407<SP>0</SP> ... 407<SP>9</SP> at a time which represents the result digit, if less than ten; if the result is in the range ten to eighteen, one of a series of tubes 408<SP>1</SP> ... 408<SP>9</SP> is fired at a time which represents this result. A head 179 records each result digit pulse received from the tubes 407<SP>0</SP> ... 407<SP>9</SP> on a tape e; a head 181, displaced by ten digital steps from the head 179, records the units digits of results registered by the tubes 408<SP>1</SP> ... 408<SP>9</SP>. The carry-over digit is accounted for by switching over from reading head 31<SP>1</SP> to a second reading head 31<SP>2</SP> displaced by one digital step, for the sensing of the next digit from the tape a. The scheme of the addition table for this embodiment is shown in Fig. 4. Other schemes are suggested including a multiplication table, Figs. 6 and 7, whereby multiplication could be effected in one cycle of the machine. Another embodiment is described in which an addition table similar to that shown in Fig. 1 is used for multiplication or division by repeated addition or subtraction. The factors are entered by keyboard and recorded in separate magnetic tracks. An auxiliary track is used for rearrangement of result digits according to whether or not there is a carry, in the manner described in Specifica. tion 786,021. A range of selectable reading heads provides shifting facilities. Specifications 786,026, 786,027, [Group XVI], 786,033, 786,034 and 786,048 also are referred to.