Wang LOCI-2 Circuit Board 1406A

The 1406A board contains the ten digit A (Accumulator) register that is used for basic addition and subtraction operations, as well as the control circuitry for addition and subtraction. The A register consists of a total of 40 flip-flops (80 transistors and associated components) that are arranged as a ten digit shift register, with each digit represented by four flip-flops, with digits stored in binary-coded decimal form. Also included is the logic for keeping track of the sign and decimal point location of the number in the A register. There is also circuitry to properly align the decimal points when performing addition and subtraction. The board also contains some of the logic relating to the addressing of the memory registers of the LOCI-2.