Compatibility: 1.0+
Expects: AH    0DH
                                                                  
Returns: none
                                                                  
Info: Flushes all file buffers.

This does NOT update file length in a directory.  To ensure a
file's length is correctly recorded, close the file via Fn 10H or

Notes:   All MS-DOS tools that buffer I/O data will honor this function,
including the SmartDrv disk cache and caching performed by
DoubleSpace.  For instance, if you want to avoid having
Smartdrv perform its periodic disk output during a time-
critical program function, use Fn 0dH before starting that
function.

  Control does not return until all buffers have been flushed.

  The default INT 23H Ctrl+Break handler calls this function when
DOS detects Ctrl+Break or Ctrl+C.

- -

DOS Fn 0dH: Reset Disk