VMS Help Sys Parameters, PSEUDOLOA  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    (VAX only) PSEUDOLOA specifies (in pages) the size of the PDA0
    system image. PSEUDOLOA is used to boot standalone BACKUP from
    magnetic tape.

    This special parameter is used by Compaq and is subject to
    change. Do not change this parameter unless Compaq recommends
    that you do so.