ALU control circuitry for simple pocket calculators - has two input shift registers, intermediate store, and four decade ALU with gating circuit

摘要

The electronic calculator circuit for addition and subtraction contains two number input shift registers, an intermediate store (25), a four-decode ALU together with a gating circuit and without decimal point operation. A value is added or subtracted from a total to implement other operations. The gating circuit switches between the result store and the display circuitry according to the flip=flop output (Z). USE - Electronic calculator circuitry.