INT 21,44 - I/O Control for Devices (IOCTL)


	Standard Call Format

	AH = 44h
	AL = function value
	BX = file handle
	BL = logical device number (0=default, 1=A:, 2=B:, 3=C:, ...)
	CX = number of bytes to read or write
	DS:DX = data or buffer


	on return:
	AX = error code if CF set
	AX = # of bytes transferred if CF not set


	For more information, see the following topics:

	IOCTL,0   Get Device Information
	IOCTL,1   Set Device Information
	IOCTL,2   Read From Character Device
	IOCTL,3   Write to Character Device
	IOCTL,4   Read From Block Device
	IOCTL,5   Write to Block Device
	IOCTL,6   Get Input Status
	IOCTL,7   Get Output Status
	IOCTL,8   Device Removable Query
	IOCTL,9   Device Local or Remote Query
	IOCTL,A   Handle Local or Remote Query
	IOCTL,B   Set Sharing Retry Count
	IOCTL,C   Generic I/O for Handles
	IOCTL,D   Generic I/O for Block Devices (3.2+)
	IOCTL,E   Get Logical Drive (3.2+)
	IOCTL,F   Set Logical Drive (3.2+)


	- see:	DEVICE COMMAND CODES
		DEVICE REQUEST HEADER
		DEVICE STATUS
		DEVICE HEADER
		DEVICE ATTRIBUTES