VMS Help DECnet-Plus, DCL Commands, DIRECTORY, Qualifiers, /COLUMNS  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /COLUMNS[=n]

    Controls the number of columns in a brief directory display. In
    practice, a display contains as many of the specified number of
    columns as can fit within the display width or the screen width
    (whichever is narrowest).

    Default value:   A four column display