After the failure of their first portable, the Macintosh Portable (released in 1989), Apple reevaluated and came back two years later with their more portable laptop, the PowerBook. Three PowerBook models were released initially; the PowerBook 100, 140, & 170. The PowerBook was revolutionary upon release with innovations like the trackball in front of the keyboard, which most computers required external mice. The PowerBook's were expensive upon release, with the lowest end model costing $2500! The PowerBook line was ultimately discontinued in 2006, to make way for the MacBook line.