The FileMode variable determines the access code to pass to DOS when typed and untyped files (not text files) are opened using the Reset procedure.

The default FileMode is 2. Assigning another value to FileMode causes all subsequent Resets to use that mode.

The range of valid FileMode values depends on the version of DOS in use. For all versions, these modes are defined:

DOS version 3.x and higher defines additional modes, which are primarily concerned with file-sharing on networks.

(For more details, see your DOS programmer's reference manual.)