Abstract: An apparatus for converting a multidigit decimal number into a binary number. In a preferred embodiment, the apparatus includes a register for holding the multidigit decimal number; first conversion logic, coupled to the register, for simultaneously converting a first pair of decimal digits in the multidigit decimal number, into a first binary representation and second conversion logic, coupled to said first conversion logic and the register, for simultaneously converting a second pair of decimal digits in the multidigit decimal number and the first binary representation into a second binary representation of a decimal number defined by the first and second pair of decimal digits.

Abstract: An essentially symmetrical ratio decoder which covers all areas in both the positive and negative regions with only a small number of noted exceptions. Multiple boundaries were selected such that the positive and negative regions were symmetrical with only a small number of exceptions. Using these boundaries, an essentially symmetrical, unified ratio decoder was constructed using only about one-half of the integrated circuit real estate of conventional ratio decoder pairs. By decoding the sign bit from the ratio decoder adder, the ratio decoder recognizes the exceptional areas and handles them accordingly.