GB1282770A - Improvements in or relating to calculating machines - Google Patents

Abstract

1282770 Digital calculator BELL PUNCH CO Ltd 3 Dec 1970 [3 Dec 1969] 58983/69 Heading G4A A digital electronic calculating machine as described in Specification 1,261,710, has a number of extra memory registers M1-M4 for holding numbers used in calculations, and extra keys whereby when a memory key is not actuated digit pulses enter an input register 24, and if the memory key is actuated the pulses enter one of the registers M1-M4, the particular register M1-M4 being chosen by a register selection key. The calculating machine functions as in the above Patent with the operands normally in the multi-stage recirculating input and accumulator registers 24, 38. Each register M1-M4 is identical to the input register and a b-stable 86 is actuated by the memory key on keyboard 8 to select whether the input register or one of the memory registers is to be used. One of the memory registers M1 to M4 has a number entered in it by depression of the memory key on keyboard 8, depression of a digit key on keyboard 5 corresponding to the selected memory register, depression of the constant key on keyboard 8, entry of the number via the digit keyboard 5 into the input register and depression of the memory enter key on keyboard 8 to copy the required number into the selected memory register and the accumulator register 38. Calculation is then effected as in Specification 1,261,710. Other added features.-The visual display 16 includes a sign display 16a which shows negative only, and a register 16c which indicates which (if any) of registers M1-M4 is in use.