 A number of chips, each with different sets of interfaces, are sold under the names ColdFire and DragonBall.Model numbers with even second-to-last digit (68000, 68020, 68040, 68060) were reserved for major revisions to the 680x0 core architecture.Model numbers with odd second-to-last digit (68010, 68030) were reserved for upgrades to the architecture of the previous chip.