My hack at boot time in Open Firmware:
>	ok> dev /PowerPC,604
>	ok> A7D8C0 encode-int " timebase-frequency" property
>	ok> boot
>
>(0xA7d8C0 is not what I used, it was slightly smaller.  This is 11M.
>My notes are upstairs)

seems to have done the trick.  I'm now gaining 0.12 seconds or
thereabouts every 4 hours.  That's less than a second a day.
Not wonderful, but acceptable.

I may tweak it a bit more to get closer, or I might try running
ntpd now, but my original question has not been addressed by anyone
on the list.

Does the NTP option in the kernel work properly?  It appears not
to be enabled by default, and that tells me that it has some downside.
If I build a kernel with the NTP option, will it work?

I'm guessing that the comments on the mac68K list about ntpd not
working has more to do with the "missing ticks" problems than
something fundamentally wrong with the code.  Is that right?

???

-dgl-