> And you only get 4 bits to use out of that byte because the leading four are a way to disambiguate it (also iirc, this stuff is terribly documented). No, it

> And you only get 4 bits to use out of that byte because the leading four are a way to disambiguate it (also iirc, this stuff is terribly documented). No, it has been extremely well documented since 2000 (three years before AMD had the first 64-bit chip ready).