My recollection may be off, but this is straight from
Woz, Al.
Woz is a nice guy, but after his plane crash / amnesia there is
a lot that he doesn't remember. The story came from Al Alcorn
who had to fix the unshippable mess that Woz created.
I had wondered about the story about a year ago, while Al and I
were going through some of the old Atari documentation that he
still has, and I made a point of asking him EXACTLY why they
couldn't ship what Woz had built. The specific part of the circuit
is the on screen score circuit. There is a fairly complicated
glob of gates there around a seven segment decoder IC which
HP had reduced to a single IC. Woz had used that part in the proto
that he built. Atari had to replace it with conventional logic.
They knew EXACTLY what he had built, they just couldn't put it
into production using the parts they could buy.