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

Here's a canned sample that will eject.   The cdrom ioctls are fully
documented in the standard ibm warp "Control Program Guide and
Reference",under "Generic Ioctl Commands --> Category 80h
..."

 -------------------------------------------------------------

 GC> Hello All!  I'm having a bit of trouble using DosOpen
 GC> to open my CD-ROM drive for access (specifically to

You were close.  Your DosOpen() parms were specified a little wrong. You
also called the ioctl with some unintilized len variables. After I fixed
those,  the program caused a kernel trap in "cdrom2$"!!.   After
about 1/2 hour of digging around the DDK (I should have just looked up the
category 0x80 stuff in the *.inf file,  instead of trying to debug the
source to the cdrom driver),  I solved the problem.  Here you go:

 // eject cdrom
 #define INCL_DOS
 #define INCL_NOPMAPI
 #include 
 #include 
 #include 

 VOID main(VOID)
 {
     HFILE CDHandle;
     ULONG action;
     APIRET rc;
     ULONG ParmLenInOut, DataLenInOut;

     rc = DosOpen("I:",
                  &CDHandle,
                  &action,
                  0,
                  FILE_NORMAL,
                  FILE_OPEN,
                  OPEN_ACCESS_READONLY | OPEN_FLAGS_DASD | OPEN_SHARE_DENYNONE,
                  NULL);

    if (rc != 0)
    {
       printf("DosOpen failed (rc = %ld)\n", rc);
       exit(EXIT_FAILURE);
    }

    ParmLenInOut = 4;    // setting these to something is important!
    DataLenInOut = 0;
    rc = DosDevIOCtl(CDHandle,
                     0x80,              // IOCTL_CDROMDISK
                     0x44,              // CDROMDISK_EJECTDISK
                     "CD01",
                     4,
                     &ParmLenInOut,
                     NULL,
                     0,
                     &DataLenInOut);

    if (rc != 0)
    {
         printf("DosDevIOCtl failed (rc = %ld)\n", rc);
         exit(EXIT_FAILURE);
    }

    DosClose(CDHandle);
 }


--- Maximus/2 3.00