<Does the 336 apply to every microprocessor system with a variable speed and an independent external clock>

No. Perfect example is Uhlenhoff prior art which White and Case was planning to use against us, but rejected. I believe it had a ring oscillator on chip and and external clock. But the critical difference was the ring oscillator would signal the external clock that it should take over because we need to access external memory. The ring oscillator would shut down until the external fetching was done. This is why the language of the second clock signaling had to be revised. The second clock signal does not originate from the ring oscillator.

<Is there such a thing as a microprocessor system with a variable speed clock that does not use a "ring oscillator" circuit???>

That's a good question. I believe the answer is yes. Much depends on what the definition of variable speed is. The frequency of a non-ring oscillator will vary according to the amount of juice or heat or other conditions, just as a ring oscillator. But those older systems could never run at max. And those are the systems that the 336 made obsolete. My 2 cents, but propably should defer to someone better qualified.

Opty