The DMX was a programmable, sample-based digital drum machine. The DMX shipped in the fall of 1981 with eight independent drum voices each containing up to three sounds, for a total of 24 drum sounds triggerable from the front panel buttons. Each voice could be individually tuned, mixed via faders, and had a direct audio output on the rear panel. Each voice was contained on its own dedicated voice card, which could be swapped out by the user with alternative drum voice cards that were sold separately. The DMX could record, save, and edit sequences and songs stored in internal battery backed-up memory, with a maximum sequence time of over 5 hours and up to 2000 events. It could also quantize and add rhythm humanizations like shuffles, flams, and rolls.