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

    Purpose:        Bit set PSW - set trap enables
    Format:         opcode mask.rw
    Operation:      PSW = PSW OR mask
    C. Codes:       N = N OR mask<3>; Z = Z OR mask<2>
                    V = V OR mask<1>; C = C OR mask<0>
    Exceptions:     Reserved operand
    Opcode:         B8    BISPSW   Bit set PSW
    Description:    The PSW is ORed with mask and PSW is replaced by the
                    result.