Revision 1 of 2, by Trev on 2-10-2020. The page as it is now.

CD open close

(Windows only)

These procedures open and close a CD / DVD drive:

pascal

uses MMSystem, ...;

...

procedure TForm1.Button1Click(Sender: TObject);
begin
// opens the CD-ROM drive
mciSendstring('SET CDAUDIO DOOR OPEN', nil , 0, Form1.Handle);
mciSendString ('close cdlw', nil, 0, 0)
end;

procedure TForm1.Button2Click (Sender: TObject);
begin
// closes the CD-ROM drive
mciSendstring('SET CDAUDIO DOOR CLOSED', nil , 0, Form1.Handle);
mciSendString ('close cdlw', nil, 0, 0)
end;

...

If you want to wait until the last operation is finished then this procedure will open/close a CD-ROM/DVD depending on the value of the blnOpen boolean variable:

pascal

uses
  MMSystem, ...;
  
  ...
  
procedure cdOpenClose(chrDriveChar: char; blnOpen: boolean);
begin
  if mciSendString(PChar('open ' + chrDriveChar + ': type cdaudio alias cdlw'), nil, 0, 0) = 0 then
    begin
      // open CD-ROM drive
      if blnOpen = True then
        mciSendString('set cdlw door open wait', nil, 0, 0)
      // close CD-ROM drive
      else
        mciSendString('set cdlw door closed wait', nil, 0, 0);

      mciSendString('close cdlw', nil, 0, 0);
    end;
end;
  
  ...

From the Free Pascal wiki, page "CD open close", as it stood on 2020-02-10 after a change by Trev, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's Licensing page. If you have concerns about this material, message the admin.