How to Address Multiple CDAudio Devices in Windows NT

ID: Q137579

The information in this article applies to:

Microsoft Win32 Software Development Kit (SDK), versions 3.5, 5.51, 4.0

SUMMARY

To use more than one CDAudio device in Windows 3.1, you had to change the System.ini file. For more information on this process, please see the following article in the Microsoft Knowledge Base:

Q82469Using Multiple CD-ROM Drives on One Machine

Now, in Windows NT 3.5 and Windows 95, support for multiple CDAudio devices has been added to the MCI CDAudio driver. However, the problem now becomes one of how to address a particular CDAudio device.

MORE INFORMATION

MCI solves the problem of how to control a particular CDAudio device. All you need to do is open the CDAudio device, specifying the drive letter of the CD-ROM drive to be used as the element to open. The MCI string syntax to do this is as follows:


   open d: type cdaudio alias cd

In this case, the CD-ROM drive is drive D:

The following code fragment demonstrates the equivalent MCI command syntax code:


    MCI_OPEN_PARMS  mciOpen;
    TCHAR           szElementName[4];
    TCHAR           szAliasName[32];
    DWORD           dwFlags;
    DWORD           dwAliasCount = GetCurrentTime();
    DWORD           dwRet;
    TCHAR           chDrive;

    chDrive = TEXT("D"); // Use drive D

    ZeroMemory( &mciOpen, sizeof(mciOpen) );
    mciOpen.lpstrDeviceType = (LPTSTR)MCI_DEVTYPE_CD_AUDIO;
    wsprintf( szElementName, TEXT("%c:"), chDrive );
    wsprintf( szAliasName, TEXT("CD%lu:"), dwAliasCount );

    mciOpen.lpstrElementName = szElementName;
    mciOpen.lpstrAlias = szAliasName;

    dwFlags = MCI_OPEN_ELEMENT | MCI_OPEN_SHAREABLE | MCI_OPEN_ALIAS |
              MCI_OPEN_TYPE | MCI_OPEN_TYPE_ID | MCI_WAIT;

    dwRet = mciSendCommand(0, MCI_OPEN, dwFlags, (DWORD)(LPVOID)&mciOpen);

    if ( dwRet == MMSYSERR_NOERROR ) {

        // The device was opened successfully

    }
    else {

        // The device was not opened successfully

    }

Additional query words: 3.50 4.00 Windows 95

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