Indicates a nonnative numeric format for unformatted data.  It
  takes the following form:

  CONVERT = fm

  fm  Is a character expression with one of the following
      options:

     'LITTLE_ENDIAN'- Little endian integer data of the
                      appropriate size (INTEGER*1, INTEGER*2,
                      INTEGER*4, or INTEGER*8) and IEEE
                      floating-point data of the appropriate size
                      and type (REAL*4, REAL*8, REAL*16, COMPLEX*8,
                      COMPLEX*16, or COMPLEX*32).  INTEGER*1 data
                      is the same for little endian and big endian.

     'BIG_ENDIAN' -   Big endian integer data of the appropriate
                      size (INTEGER*1, INTEGER*2, INTEGER*4, or
                      INTEGER*8) and IEEE floating-point data of
                      the appropriate size and type (REAL*4, REAL*8,
                      REAL*16, COMPLEX*8, COMPLEX*16, or COMPLEX*32).
                      INTEGER*1 data is the same for little endian
                      and big endian.

     'CRAY' -         Big endian integer data of the appropriate
                      size (INTEGER*1, INTEGER*2, INTEGER*4, or
                      INTEGER*8) and CRAY floating-point data of
                      size REAL*8 or COMPLEX*16.

     'FDX' -          Little endian integer data of the appropriate
                      size (INTEGER*1, INTEGER*2, INTEGER*4, or
                      INTEGER*8) and HP VAX floating-point data
                      of format F_floating for REAL*4 or COMPLEX*8,
                      D_floating for size REAL*8 or COMPLEX*16, and
                      IEEE X_floating for REAL*16 or COMPLEX*32.

     'FGX' -          Little endian integer data of the appropriate
                      size (INTEGER*1, INTEGER*2, INTEGER*4, or
                      INTEGER*8) and HP VAX floating-point data
                      of format F_floating for REAL*4 or COMPLEX*8,
                      G_floating for size REAL*8 or COMPLEX*16, and
                      IEEE X_floating for REAL*16 or COMPLEX*32.

     'IBM' -          Big endian integer data of the appropriate
                      size (INTEGER*1, INTEGER*2, INTEGER*4, or
                      INTEGER*8) and IBM System\370 floating-point
                      data of size REAL*4 or COMPLEX*8 (IBM
                      short 4) and size REAL*8 or COMPLEX*16 (IBM
                      long 8).

     'VAXD' -         Little endian integer data of the appropriate
                      size (INTEGER*1, INTEGER*2, INTEGER*4, or
                      INTEGER*8) and HP VAX floating-point
                      data of format F_floating for size
                      REAL*4 or COMPLEX*8, D_floating for size
                      REAL*8 or COMPLEX*16, and H_floating for
                      REAL*16 or COMPLEX*32.

     'VAXG' -         Little endian integer data of the appropriate
                      size (INTEGER*1, INTEGER*2, INTEGER*4, or
                      INTEGER*8) and HP VAX floating-point
                      data of format F_floating for size
                      REAL*4 or COMPLEX*8, G_floating for size
                      REAL*8 or COMPLEX*16, and H_floating for
                      REAL*16 or COMPLEX*32.

     'NATIVE' -       No data conversion.  This is the default.

  You can use CONVERT to specify multiple formats in a single
  program, usually one format for each specified unit number.

  When reading a non-native format, the non-native format on disk is
  converted to native format in memory.  If a converted non-native
  value is outside the range of the native data type, a run-time
  message appears.

  There are other ways to specify numeric format for unformatted
  files:  you can specify an OpenVMS logical name or the compiler
  option /CONVERT (or OPTIONS/CONVERT).  The order of precedence is
  OpenVMS 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 following source code shows how to code the OPEN statement to
  read unformatted CRAY numeric data from unit 15, which might be
  processed and possibly written in little endian format to unit 20:

     OPEN (CONVERT='CRAY', FILE='graph3.dat', FORM='UNFORMATTED',
    1     UNIT=15)
     ...
     OPEN (FILE='graph3_native.dat', FORM='UNFORMATTED', UNIT=20)