private void U12AddClick(object sender, EventArgs e)
        {
            OpenFileDialog OF = new OpenFileDialog
            {
                Title            = "Load a U12 ROM",
                InitialDirectory = ROMImportDir,
                Filter           = "All files (*) | *.*"
            };

            if (OF.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                OF.FilterIndex = 0;
                ROMImportDir   = System.IO.Path.GetDirectoryName(OF.FileName);
                U12List.Nodes.Add(OF.FileName);
                U12List.EndUpdate();
            }
        }
 private void U12ClearClick(object sender, EventArgs e)
 {
     U12List.Nodes.Clear();
     U12List.EndUpdate();
 }