In fact, the "History" doesn't provide much technical detail (as you might
expect).
And at least the early versions of "Beneath Apple DOS" didn't have the details
right, either.
The first description of the actual head positioning and recording method that
I saw was a text file from a member of a user group, around 1980. The writer
had actually reverse-engineered not only RWTS, but the Disk ][ Controller
state machine. It seems likely that this description might be available on
the Web somewhere, but I can't find it at the moment.
The best, and most accurate, description currently "available" is Jim Sather's
books, "Understanding the Apple II" and "Understanding the Apple //e", which
have become hard to find (though they do turn up on eBay from time to time).
If anyone knows how to contact Jim, I would not be surprised if he would
consent to posting the chapter on the Disk ][ Controller. This controller
is perhaps one of the most beautiful designs ever to emerge in the PC
age, and it would be great if it were more publicly visible.
-michael