)
Values for IOCTL category code:
 00h	unknown (DOS 3.3+)
 01h	COMn: (DOS 3.3+)
 02h	reserved for terminal control
 03h	CON (DOS 3.3+)
 04h	reserved for keyboard control
 05h	LPTn:
 07h	mouse control (European MS-DOS 4.0)
 08h	reserved for disk control -- same as for block devices
	(see INT 21/AX=440Dh)
 9Eh	Media Access Control driver (STARLITE)
 00h-7Fh reserved for Microsoft
 80h-FFh reserved for OEM/user-defined
SeeAlso: #01558