Fecha de publicación: 20/01/1987 Fuente: Wipo "digitalization" A data processing system having a central processing unit (CPU) capable of performing binary and decimal arithmetic software instructions is disclosed. The CPU includes a microprocessor which executes the binary arithmetic software instructions under firmware control. Also disclosed is apparatus utilizing a programmable memory and logic circuits that are used to subtract two operands and to generate and temporarily store a digit equal nine indication when the result of subtracting the two operands has a value of nine.