INT 21 - CD-ROM device driver - IOCTL OUTPUT
AX = 4403h
BX = file handle referencing character device for CD-ROM driver
CX = number of bytes to write
DS:DX -> control block (see below)
Return: CF clear if successful
AX = number of bytes actually written
CF set on error
AX = error code (01h,05h,06h,0Dh) (see AH=59h)
SeeAlso: INT 2F/AX=0802h

Format of control block:
Offset  Size    Description
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

See also: 214402

214403 - CD-ROM device driver - IOCTL OUTPUT