GR-20 Updates & Drivers GR-20 System Update Version 2.00 (PC) This is the Version 2 Operating System for the GR-20, adding support for Bass. Please refer to the "readme.pdf" for the update procedure. GR-20 System Update Version 2.00 (MAC) This is the Version 2 Operating System for the GR-20, adding support for Bass. Please refer to the "readme.pdf" for the update procedure. SMF Player for Windows