One important showdown occurred when Atkinson decided that the screen should have a white background rather than a dark one.
This would allow an attribute that both Atkinson and Jobs wanted: WYSIWYG, pronounced "wiz-ee-wig," an acronym for "What you see is what you get."
What you saw on the screen was what you'd get when you printed it out.
"The hardware team screamed bloody murder," Atkinson recalled.
"They said it would force us to use a phosphor that was a lot less persistent and would flicker more."
So Atkinson enlisted Jobs, who came down on his side.
The hardware folks grumbled, but then went off and figured it out.
"Steve wasn't much of an engineer himself, but he was very good at assessing people's answers.
He could tell whether the engineers were defensive or unsure of themselves."
One of Atkinson's amazing feats (which we are so accustomed to nowadays that we rarely marvel at it) was to allow the windows on a screen to overlap so that the "top" one clipped into the ones "below" it.
Atkinson made it possible to move these windows around, just like shuffling papers on a desk, with those below becoming visible or hidden as you moved the top ones.
Of course, on a computer screen there are no layers of pixels underneath the pixels that you see, so there are no windows actually lurking underneath the ones that appear to be on top.
To create the illusion of overlapping windows requires complex coding that involves what are called "regions."
Atkinson pushed himself to make this trick work because he thought he had seen this capability during his visit to Xerox PARC.
In fact the folks at PARC had never accomplished it, and they later told him they were amazed that he had done so.
"I got a feeling for the empowering aspect of naivet," Atkinson said.
"Because I didn't know it couldn't be done, I was enabled to do it."