F Implementation details

The implementation uses FORTRAN I/O and FORTRAN 77 standards are used with the following exceptions:

F.1 Alpha OSF/1

• The READONLY keyword is used when opening files for reading only. This is required under VMS to allow a user to open a file for which only read access is permitted.
• The CARRIAGECONTROL keyword is used.
• The ACCESS $=$ APPEND keyword is available to permit the useful but non-standard facility of appending to files.
• The RECL option on the OPEN statement is allowed with sequential files.
• The keyword ORGANIZATION (= ’RELATIVE’) is used when creating direct access files.
• A byte array is used as the buffer for direct access I/O.

F.2 Sun4 Solaris

• The ACCESS $=$ APPEND keyword is available to permit the useful but non-standard facility of appending to files.

F.3 Ultrix and sunOS/4

These are no longer fully supported but the same features apply as for alpha OSF/1 and sun4 Solaris respectively.

F.4 VMS

• The READONLY keyword is used when opening files for reading only. This is required under VMS to allow a user to open a file for which only read access is permitted.
• The CARRIAGECONTROL keyword is used.
• The ACCESS $=$ APPEND keyword is available to permit the useful but non-standard facility of appending to files.
• The RECL option on the OPEN statement is allowed with sequential files.
• Keywords BLOCKSIZE ($=$ 11*512) and ORGANIZATION (= ’RELATIVE’) are used when creating direct access files.
• A byte array is used as the buffer for direct access I/O.

Note that the VMS implementation is frozen at release 1.4.