Parallel string processor and method for a minicomputer

Abstract

A processor is disclosed for use in a computer system for comparing a number of bytes simultaneously in order to locate a control character in a string of data. The processor includes a register for holding the data bytes, a register for storing the control characters, a comparison circuit for simultaneously comparing the bytes of the first register with the bytes of the second register, and a circuit for generating indicator bits when a match has been found between the two registers. Microcode instructions cause the system to branch to a predetermined memory location when the control character has been located and to branch to a second predetermined memory location when no control character is found in the data string. In another aspect, a parallel string processor for a minicomputer for searching portions of text or binary bit strings for the presence of desired words or bit strings. The processor includes a first register in which a keyword string is stored and a pair of interconnected shift registers in which the string to be searched for the presence of the keyword is stored. An arithmetic logic unit compares the contents of the first register with one of the shift registers to determine whether the keyword is present in the portion of the string being searched. After each such comparison, the contents of the interconnected shift registers are shifted with respect to the keyword stored in the first register. When the processor is searching for the presence of a keyword having a predetermined number of bytes, the contents of the shift registers are shifted one bytes at a time, and when the processor is searching for the presence of a keyword having a predetermined number of bits, the contents of the shift registers are shifted one bit at a time.