VMS Help FORTRAN, /CONVERT, BIG_ENDIAN  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Specifies that numeric data in unformatted files is in big endian
  integer data of the appropriate size (INTEGER*1, INTEGER*2, or
  INTEGER*4) and IEEE floating-point data of the appropriate size and
  type (REAL*4, REAL*8, COMPLEX*8, or COMPLEX*16).

  INTEGER*1 data is the same for little endian and big endian.