Arithmetic algorithms for error-coded operands.

Abstract

Arithmetic algorithms for separate and nonseparate codes are considered. The nonseparate AN code is formed when an uncoded operand X is multiplied by the check modulus A to give the coded operand AX. The separate codes are the residue code, and the inverse-residue code, which has significant advantages in fault detection of repeated-use faults. A set of algorithms for low-cost AN-coded operands is discussed together with questions of their implementation in a byte-organized arithmetic processor. Algorithms for inverse-residue coded operands of the STAR computer are also examined.