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

  /[NO]CONVERT=option        D=/CONVERT=NATIVE

  Specifies a nonnative numeric format for unformatted data.

  By default, an unformatted file containing numeric data is assumed
  to be in the little endian floating-point or integer format used
  for memory representation (/CONVERT=NATIVE or /NOCONVERT).

  There are other ways to specify numeric format for unformatted
  files:  you can specify a VMS logical name, OPEN (CONVERT=) or
  OPTIONS/CONVERT.  The order of precedence is VMS logical name, OPEN
  (CONVERT=), OPTIONS/CONVERT, and then compiler option /CONVERT.
  The /CONVERT compiler option and OPTIONS/CONVERT affect all unit
  numbers used by the program, while logical names and OPEN
  (CONVERT=) affect specific unit numbers.

  The /CONVERT compiler option specifies a default data-conversion
  type for all logical units opened in the program unit, either
  explicitly by an OPEN statement or implicitly by a READ, WRITE or
  other I/O statement (with the exception of DEFINE FILE).  You can
  override the default data-conversion type by specifying the
  CONVERT= keyword in the OPEN statement or by defining a logical
  name of the form FOR$CONVERTnnn, where "nnn" is the logical unit
  number (including leading zeros if necessary).

  For more information on using unformatted data files, using VMS
  logical names to specify CONVERT options, and information about the
  ranges of the various data types, see your user manual.

  Additional Information (explode) :

• BIG_ENDIAN
• CRAY
• FDX
• FGX
• IBM
• LITTLE_ENDIAN
• NATIVE
• VAXD
• VAXG