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

  RECL = rl

  rl  Is an numeric expression whose value indicates the length
      of logical records in a file.

  The value of "rl" does not include space for control information,
  such as for two segment control bytes (if present) or the bytes
  that RMS requires for maintaining record length and deleted record
  control information.  The specification is for record data only.

  The value of "r1" is expressed in units of bytes or longwords,
  depending on the record's format.  Formatted records use byte units
  and unformatted records use longword units (which are equal to 4
  bytes).

  The following are the maximum values that can be specified for "r1"
  for disk files that use the fixed-length record format:

    Sequential formatted               32767 bytes
    Sequential unformatted              8191 longwords
    Relative formatted                 32255 bytes
    Relative unformatted                8063 longwords
    Indexed formatted                  32224 bytes
    Indexed unformatted                 8056 longwords
    Tape formatted                      9999 bytes
    Tape unformatted                    2499 longwords

  For other record formats and device types, the record size limit
  can be less, as described in the "OpenVMS Record Management
  Services Reference Manual".

  RECL is mandatory when opening new files (STATUS='NEW', 'UNKNOWN,
  or 'SCRATCH') and when one or more of the following conditions
  exists:

   o  The record format is fixed length (RECORDTYPE='FIXED').

   o  The file organization is relative or indexed
      (ORGANIZATION='RELATIVE' or 'INDEXED').

   o  The file is opened for direct access (ACCESS='DIRECT').

  RECL is optional in all other cases.  Default values for optional
  cases depend on the value of the RECORDTYPE parameter.

  The following are the RECL default values:

  RECORDTYPE value    RECL value
  ----------------    -----------------------------------------

  'FIXED'             None; value must be explicitly specified.
  All other types     133 bytes (for formatted records)
                      511 longwords (for unformatted records)

  The interpretation and effect of the logical record length varies
  as follows:

   o  If the file contains segmented records, RECL specifies the
      maximum length for any segment (including the two
      segment-control bytes).

   o  If the file contains fixed-length records, RECL specifies the
      size of each record.

   o  If the file contains variable-length records, RECL specifies
      the maximum length for any record.

   o  If your program attempts to write to an existing file a record
      that is longer than the logical record length, an error occurs.

   o  If you are opening an existing file that contains fixed-length
      records or has relative organization and you specify a value
      for RECL that is different from the actual length of the
      records in the file, an error occurs.