 Some years later, enthusiasts developed the NitrOS9 operating system based upon the original Microware OS9.Series II of the Fairlight CMI (computer musical instrument) used dual 6809 CPUs and OS9, and also used one 6809 CPU per voice card.The 6809 was often employed in music synthesizers from other manufacturers such as Oberheim (Xpander, Matrix 6/12/1000), PPG (Wave 2/2.2/2.3, Waveterm A), and Ensoniq (Mirage sampler, SDP-1, ESQ1, SQ80).