with frmMain.ImageEnMView1.MIO do
  begin
    {DEVICES INTO CBO LIST}
    AcquireParams.FillListWithSources( cboSource.Items );
...

{DEVICES INTO CBO LIST}
    sl := TStringList.Create;
    try
    cboSource.Clear;
    AcquireParams.FillListWithSources(sl);
    for i := 0 to sl.Count - 1 do
      cboSource.Items.Add(Copy(sl[i],1,Pos('|',sl[i])-1));
    finally
      FreeAndNil(sl);
    end;

ImageEnMView1.MIO.AcquireParams.FillListWithSources( cboSource.Items, [], True );

// Save the current acquisition source to the registry
procedure TMainForm.FormClose(Sender: TObject; var Action: TCloseAction);
var
  sDevice : string;
begin
  ...
  // Read the selected device
  sDevice := AcquireSourceToStr( ImageEnMView1.MIO.SelectedAcquireSource );
  WRegistry.WriteString( 'SelectedAcquireSource', sDevice );
  ...
end;

// Read the current acquisition source to the registry
procedure TMainForm.FormShow(Sender: TObject);
var
  sDevice : string;
  ADevice : TIEAcquireSource;
begin
  ...
  // Restore the device selection
  sDevice := WRegistry.ReadString( 'SelectedAcquireSource', '' );
  if sDevice <> '' then
  begin
    ADevice := StrToAcquireSource( sDevice );
    ImageEnView1.IO.SetAcquireSource( ADevice.Api, ADevice.Location );
    Label1.Caption := 'Scanner: ' + ADevice.Name;
  end;
  ...
end;

for i := 0 to frmMain.ImageEnView1.IO.TwainParams.SourceCount - 1 do
    cboSource.Items.Add( String( frmMain.ImageEnView1.IO.TwainParams.SourceName[i] ));

frmMain.ImageEnMView1.MIO.AcquireParams.FillListWithSources( cboSource.Items, [], True );