Apple II - Power Source

Power Source

Wozniak, whose passion was the circuitry, didn't concern himself with the issue of heat. But the power source necessary to keep all those circuits functioning can make a lot of heat, and that can require a fan, a low-tech contraption in itself, to disperse said heat. Steve Jobs thought fans an inelegant solution, and looked for someone who could come up with a better one.

Rod Holt is credited (for example in the Walter Isaacson biography of Jobs) with the solution. Holt employed a Switched-mode power supply design. This generated far less unwanted heat than a linear power supply, which most other home computers of the time used.

Isaacson quotes Wozniak saying that this was not something he could have done. "I only knew vaguely what a switching power supply was."