The 'Happy' upgrade for these drives comprised of single chip added to the drive, and software run during the boot-up of the Atari 8bit machine. It dramatically improved the speed of the drive, raising the transfer rate to 52k vice the standard 19.2k, as well as allowed the drive to copy nearly any 810-format diskette. The software for the upgrade went through many revisions during it's production. Needless to say, this product was a favorite for copying commercial software, which often used on-disk copy protection.