time ago appears to be based not on the typical 1.8432MHz clock, or
the other more typical multiple of 8 of this (14.7456MHz), but instead
it appears to be 1/2 the PCI clock rate or 16.50000MHz. I'm not 100%
sure that this is right, but since I did the original entry, I'm going
to go ahead and modify it. With the 14.7456MHz value, I was getting
bits that were ~7.3us instead of ~8.6us like they are supposed to be.
My measuring gear for today is a stupid handheld scope with two
signficant digits. So I don't know if it is 33.000000/2 MHz or some
other value close to 16.5MHz, but 16.5MHz works well enough for me to
use a couple of different devices at 115200 baud, and is a nice even
multiple of a well known clock frequency...