On Mon, 13 Mar 2000, Bill Studenmund wrote:

> On Mon, 13 Mar 2000, Simon Baker wrote:
> 
> > BTW, you should be aware that mac's are notoriously bad for keeping 
> > time.  See http://www.macbsd.com/macbsd/macbsd-docs/faq/faq-3.html#ss3.17 
> > for an explanation....
> 
> Uhm, that FAQ is for m68k macs. Interrupt handling on powermacs is
> different, and the clock should be able to run at a higher interrupt
> level.
> 
> If it's systematically sucking on a powermac, we should look at the
> problem. :-)

If I'm remembering correctly how MkLinux does this stuff....  The clock on
a Powermac shouldn't even _use_ interrupts except for keeping the OS
up-to-date.  The processor has a RTC built-in that counts in nanoseconds.  
If you have a clock drift beyond the natural frequency drift of the
crystal, you're doing something wrong.  ;-)

Note: RTC in PowerPC context is not the same as an RTC in x86 context. 
RTC in x86 context is equivalent to the bbclock (battery backed clock) in
PowerPC context, which ticks in seconds, IIRC.


David