Patrick Haller wrote in a message to All / Peter Fitzsimmons:

 PH> Recently I found two interesting IOCtl-definitons when
 PH> browsing BSEDEV.H: IOCTL_CDROMDISK and IOCTL_CDROMAUDIO.

The API to OS2CDROM.DMD is mostly documented in the section "CD-ROM
Device Manager Interface Specification" in the IBM OS/2 Storage Device
Driver Reference, part number 71G1897.  You can buy it in paper format or
as part of the DevCon DDK subscription on CD-ROM by calling (800)6-DEVCON.

 PH> But I can't figure out, what my I/O-parameters/packets for
 PH> DosDevIOCtl have to look like so the OS2CDROM.CMD will
 PH> accept them. I keep getting an rc=65283. What does this
 PH> return code mean ?

OS/2 will bitwise-OR 0xFF00 with any value returned from an IOCtl, so your
65283 is 0xFF03, which means that the IOCtl function returned 0x0003. 
While the return codes from an IOCtl are technically user-defined, in
practice a zero return code indicates success and a non-zero return code
usually follows the common definitions in BSEERR.H -- at it does here,
where 0x0003 is the code for ERROR_I24_BAD_COMMAND.

 PH> I'd just like to implement a tool for "CDROM /EJECT" or
 PH> "CDROM /PLAYAUDIO", etc.

You could do this, but you would have to study the OS2CDROM.DMD source code.
 
-- Mike


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