 ND also sold multiprocessor configurations, naming them ND-580/"n" and an ND-590"n", where "n" represented the number of CPUs in a given configuration, 2, 3, or 4.Sold as the ND-500, ND-520, ND-540, and ND-560.Sold as the ND-570, ND-570/CX, and the ND-570/ACX.