Digital electronic circuit for multiplication, division, addition and subtraction - has switched tetrade circuit, shift registers combined with adder, and resets flip=flops by operation of key

摘要

A digital electronic circuit provides all four basic arithmetic operations that are selected by operation of keys on a panel. The circuit is based around an adder logic circuit that is combined with a number of shift registers and a pulse generator. The input selections of the addition, subtraction, multiplication and division operations are controlled by flip flops (1-5) that receive reset inputs from the selector keys (M,D,A,S). Numbers entered include a decimal point. By actuation of a key (M), the flip-flops of one circuit (21b) are reset.