Gavin Ivester is currently VP of Design at Bang & Olufsen. He started his career at Apple though, working on the PowerBook. He told TechRader how the product took shape.
The ergonomic goal was to get that front edge to be as thin as possible, for comfort, assuming you would use the laptop on a desk. The breakthrough came from a system integration engineer named Jonathan Krakower, who proposed we push the keyboard back, and then put the battery in one of the now-empty front corners, and the disc drive in the other corner. That left a space in the middle for some kind of cursor control, and trackballs were the best solution at that moment… My challenge was then to design options to bring that layout idea to life as a product, prototype them, test them with real users, and design better ones until we either had a final design or proved it would never work.
Check It Out: The Story Behind Apple PowerBook’s Design