Category: <b>disk I/O enhancements</b>
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<pre><b>INT 21 - CD-ROM device driver - IOCTL INPUT</b>

	AX = 4402h
	BX = file handle referencing character device for CD-ROM driver
	CX = number of bytes to read
	DS:DX -&gt; control block (see <a href=../../it/49/14.html>#01449</a>)
Return: CF clear if successful
	    AX = number of bytes actually read
	CF set on error
	    AX = error code (01h,05h,06h,0Dh) (see <a href=../../it/80/16.html>#01680</a> at AH=59h/BX=0000h)
Notes:	the data returned depends on the first byte of the control block
	  (two bytes for functions 01h/07h/0Bh, see <a href=../../it/49/14.html>#01449</a>); the remainder of
	  the control block is filled by the driver
	some device drivers support several subunits (that is more than one
	  drive) but it is not possible to distinguish between them with this
	  function; use INT 2F/AX=1510h or INT 2F/AX=0802h instead
	under Windows95, the "mscd$$$$" device cannot be opened so you cannot
	  obtain the handle required by this function: use INT 2F/AX=1510h
	  or INT 2F/AX=0802h instead
SeeAlso: AX=4403h"CD-ROM",INT 2F/AX=0802h,INT 2F/AX=1510h

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