VMS Help MACRO, VAX MACRO Assembler, Instructions, LOCC  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Purpose:        To locate a character in a string
    Format:         opcode char.rb,len.rw,addr.ab
    Operation:      {compare each character until equal}
    C. Codes:       N = 0, Z = {R0 EQL 0}, Z = 0, C = 0
    Exceptions:     None
    Opcode:         3A    LOCC     Locate character
    Description:    char is compared with the bytes of the string
                    specified by addr and len. Comparison continues
                    until char equals the character in the string or
                    until the string is exhausted. If equality is
                    detected the Z bit is cleared, otherwise it is set.
    Notes:          After execution:

                    R0 = number of bytes remaining in the string
                         (including located one) if byte located;
                         otherwise 0
                    R1 = address of the byte located if located;
                         otherwise address of one byte beyond the
                         string