Electronic adder and subtractor for 8421 code - uses five flip=flops per decade to provide display facility

摘要

A binary circuit for the addition and subtraction of 8421 coded numbers operates together with a decimal display facility. Each decade consists of five or more flip flops, and has the capacity to press the interstage carries that are generated. One decade of the adder/substractor circuit has five flip flops. Voltage is supplied over a common pair of lines, with a further line used for control and reset applied over another line (h). Reset produces the combination to generate a zero display condition. Each flip flop is formed from a cross coupled pair of transistors together with diodes and resistors. Carries are transmitted over transistors.