Wang LOCI-2 Circuit Board 1403A

The 1403A board contains a twelve digit binary-coded decimal register that makes up the L (Logarithm) register of the calculator. The register contains 48 flip-flips arranged as a 4-bit by 12-digit register. The register is configured as a shift register. Also included is the adder circuitry to allow the logarithms to be generated in this register, as well as logarithms to be added to or subtracted from the register. The register has an implied decimal point after the first two digits. Also included on the board is the sign flip flips for the L and W registers. Lastly, logic on the board generates some control signals that are related to entering numbers into the W register from the keyboard or punched card reader.