Support for multiple sound engines. The existing engine is named blanket stitch.
    New running stitch engine, which has a faster (but variable) loop time.
    Output to cassette port in addition to speaker port.
    New standalone player.
    Display edit/play status.
    Release source for the sound engines.
    Adjust range after a delete operation (it may be pointing outside of song data).
    Reset row, field, and range when a song is opened.