Patent GB-679813-A (GB)
Title: Improvements in or relating to calculating machines
Filed: 1947-04-01
Abstract: 679,813. Calculating apparatus; electrical and mechanical. MARTIN, C. G. HOLLAND-. March 18, 1948 [April 1, 1947], No. 8798/47. Class 106 (i). Apparatus for the translation of a number in binary rotation into another rotation having even radix or radices, comprises a multidenominational adding device having a denomination for each denomination required in the other notation, means for simultaneously entering and adding in the lowest denomination of the adding device all the powers of two represented in the binary number, means for entering and adding in each higher denomination carries from the next lower denomination, said carries being powers of two in the denomination into which they are entered, and means for indicating or recording the value in each denomination of the translated number. An apparatus for the translation of a number in the binary notation into its equivalent in the decimal notation is shown in Fig. 2. The binary number is entered on a keyboard, not shown, by depressing the keys of those binary denominations in which a " 1 " occurs, this results in the energization of relays 4 arranged to control switch contact arms 5 in a " units " chain. Each relay 4 and its associated contact arms form a link in the chain. The circuit path through a link is, therefore, as shown in Fig. 2, dependent on the energization or non-energization of the corresponding relay and on the point of exit from the preceding link. Provision is made, therefore, for the addition, at each link, of the decimal value of the associated relay and every point of entry to or exit from a link has a definite decimal value. When in the " units " chain there is reached a point having a value which is equal to or greater than the highest power of two in the tens denomination within the limits of the apparatus a connection is made to the appropriate relay in a " tens " chain of relays 7. In a similar way connections are made between definite points in the " units " chain and the succeeding relays 7 in the " tens chain. Transfer from the " tens " chain of relays 7 to the " hundreds " chain of relays 9 is effected in the same way. For any binary number entered on the keyboard there is a definite path through each denominational chain. Lamps 6 are connected to the exit point of the last link in each chain to indicate the decimal number. Electrically controlled printing apparatus may be substituted for the lamps 6. Each contact arm may be replaced by a pair of pentode valves 12, 13 arranged in the circuit shown in Fig. 5, so that one or other can be made to conduct. In a mechanical arrangement, Fig. 6, the relays are replaced by keys 23, the stems of which carry movable pins which transmit downward movement of a pin 26 at the start of the first link in the chain to one of two pins at the start of each succeeding link. Carriers are taken to the " tens " chain by means of bell-crank lever and slide arrangements such as 44, 47 to transmit through linkage outward movement of a pin carrying slide 51, which in this denomination takes the place of a key stem. The slide 47 is also provided with a cam surface 52 to cause downward movement of the appropriate pin 53 in the " units " link succeed. ing that from which the carry has been effected. The operation of the mechanical apparatus is therefore analogous to the operation of the electrical apparatus described above.