/sys$common/syshlp/helplib.hlb RTL Routines, MTH$, MTH$RANDOM, Argument  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 seed

    OpenVMS usage:longword_unsigned
    type:         longword (unsigned)
    access:       modify
    mechanism:    by reference

    The integer seed, a 32-bit number whose high-order 24 bits
    are converted by MTH$RANDOM to an F-floating random number.
    The seed argument is the address of an unsigned longword that
    contains this integer seed. The seed is modified by each call to
    MTH$RANDOM.