See: Fn 4400H (query device/file type)              2.0+
Fn 4401H (set file/device flags)               2.0+
Fn 4402H (get control data from char device)   2.0+
Fn 4403H (send control data to char device)    2.0+
Fn 4404H (get control data from block device)  2.0+
Fn 4405H (send control data to block device)   2.0+
Fn 4406H (get input status)                    2.0+
Fn 4407H (get output status)                   2.0+
Fn 4408H (removable media query)               3.0+
Fn 4409H (remote device or SUBST drive query)  3.1+
Fn 440aH (remote handle query)                 3.1+
Fn 440bH (sharing retry count)                 3.0+

Fn 440cH     (Generic IOCTL: character devices)
Fn 440cH 45H (set iteration count)             3.3+
Fn 440cH 4aH (select a prepared code page)     3.3+
Fn 440cH 4cH (begin preparing a code page)     3.3+
Fn 440cH 4dH (done preparing a code page)      3.3+
Fn 440cH 5fH (set display information)         4.0+
Fn 440cH 65H (query retry iteration count)     3.3+
Fn 440cH 6aH (query active code page)          3.3+
Fn 440cH 6bH (get list of prepared code pages) 3.3+
Fn 440cH 7fH (query display information)       4.0+

Fn 440dH     (generic IOCTL: block devices)
Fn 440dH 40H (set device parameters)           3.2+
Fn 440dH 41H (write track)                     3.2+
Fn 440dH 42H (format and verify track)         3.2+
Fn 440dH 46H (set media ID)                    4.0+
Fn 440dH 47H (set disk access flag)            4.0 only
Fn 440dH 60H (get device parameters)           3.2+
Fn 440dH 61H (read track)                      3.2+
Fn 440dH 62H (verify track)                    3.2+
Fn 440dH 66H (query media ID)                  4.0+
Fn 440dH 67H (query disk access flag)          4.0 only
Fn 440dH 68H (sense media type)                5.0+

Fn 440eH (get logical drive)                   3.2+
Fn 440fH (set logical drive)                   3.2+
Fn 4410H (query IOCTL handle)                  5.0+
Fn 4411H (query IOCTL device)                  5.0+

Note: IOCTL is handled by device drivers and therefore the level of
support is controlled by the version of the driver as opposed to
the version of DOS.

- -

DOS Fn 44H: Device I/O Control -- IOCTL