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

    Purpose:        To skip a character in a string
    Format:         opcode char.rb,len.rw,addr.ab
    Operation:      {compare each character until not equal}
    C. Codes:       N = 0, Z = {R0 EQL 0}, Z = 0, C = 0
    Exceptions:     None
    Opcode:         3B    SKPC     Scan characters
    Description:    char is compared with the bytes of the string
                    specified by addr and len. Comparison continues until
                    char does not equal the character in the string or
                    until the string is exhausted. If inequality is
                    detected, the Z bit is cleared; otherwise, the Z bit
                    is set.
    Notes:          After execution:

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

                    If the string has 0 length, condition code Z is set
                    just as though each byte of the entire string were
                    equal to the character.