INT 21,44,3 / IOCTL,3 - Write to Character Device

	AH = 44h
	AL = 03
	BX = handle
	CX = number of bytes to send
	DS:DX = pointer to data buffer

	on return
	AX = number of bytes written if CF clear
	   = error code if CF set   (see DOS ERROR CODES)

	- see bit 14 if IOCTL function 00h to determine if
	  driver can support IOCTL control strings