Device Checking                    {$D+}                             pp 316

 Default:   Active

 Scope:     Local

 Active:    {$D+}  I/O to device files are not buffered.

 Inactive:  {$D-}  I/O to device files is buffered.


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 Notes:     When a text file os opened by RESET, REWRITE or APPEND the
            status of the file is checked if the D directive is active.

            If DOS reports that the file is a device, then buffering is
            disabled and all I/O to the file is done on a character by
            character basis.

            The D directive set to inactive will disable this check and
            force all device I/O to buffered operation.