Int 21 Fn 4403  - Cd-rom Device Driver - Ioctl Output                      [d]

   AX = 4403h
   BX = file handle referencing character device for CD-ROM driver
   CX = number of bytes to write
   DS:DX -> control block (see #1211)

Return: CF clear if successful
       AX = number of bytes actually written
   CF set on error
       AX = error code (01h,05h,06h,0Dh) (see #1366 at AH=59h/BX=0000h)

Notes: 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

See Also: AX=4402h"CD-ROM",INT 2F/AX=0802h,INT 2F/AX=1510h

Format of CR-ROM control block:
Offset Size    Description (Table 1211)
 00h   BYTE    function code
       00h eject disk
       01h lock/unlock door
       02h reset drive
       03h control audio channel
       04h write device control string
       05h close tray
---functions 00h,02h,05h---
 no further fields
---function 01h---
 01h   BYTE    lock function
       00h unlock door
       01h lock door
---function 03h---
 01h   BYTE    input channel (0-3) for output channel 0
 02h   BYTE    volume for output channel 0
 03h   BYTE    input channel (0-3) for output channel 1
 04h   BYTE    volume for output channel 1
 05h   BYTE    input channel (0-3) for output channel 2
 06h   BYTE    volume for output channel 2
 07h   BYTE    input channel (0-3) for output channel 3
 08h   BYTE    volume for output channel 3

Note:  output channels 0 and 1 are left and right, 2 and 3 are left prime and
     right prime; a volume of 00h is off
---function 04h---
 01h  N BYTEs  bytes to send directly to the CD-ROM drive without
         interpretation