Library /sys$common/syshlp/sysgen.hlb SHOW, /UNIBUS, Qualifier, /ADAPTER  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /ADAPTER=nexus

    Specifies that the address of the specified UNIBUS adapter is to
    be displayed. The nexus value specifies the number of the UNIBUS
    adapter. It can be expressed as an integer or as one of the names
    listed by the SYSGEN command SHOW/ADAPTER.