Re: Clock drift?

[Tim Preston <tim%flibble.org@localhost>]

Michael K. Sanders wibbled one day
> I had this exact same problem with my A3000 under NetBSD 1.0, and
> I never found a solution. I ended up running ntpdate once an hour
> from cron to keep the clock current... if anyone knows why xntpd
> just stops working after a while, I'd like to know too.
> 
> :: Mike ::
> 
> In message 
> <Pine.NEB.3.96.970705040354.4291J-100000%blkhole.resun.com@localhost>, Net BSD
>  Support writes:
> >Hi, All:
> >
> >I've just finished installing xntpd on my A3000, running NetBSD 1.2.
> >When running under SVR4, I suffered a lossage of time >30 seconds per
> >day.  Xntpd would seem to be the answer, but after about 4 hours of
> >running, it no longer syncronizes the clock.  I'm guessing that this
> >is because the drift on my clock is too great.  Also, the 'tickadj'
> >program provided as part of the package wants to use a tickadj of 5
> >instead of the kernel value of 40.  When it tries to open /dev/kmem to
> >make the change, the open is refused.
> >
> >Does anybody have any suggestions on what I could do to fix the clock?

Quick thought...


A3000s have a jumper to set the Angus into either PAL or NTSC mode. as
screens it PAL at 50 Hz are noticbaly flickery many people kick PAL
models into NTSC mode.

Genuine NTSC machines have a slightly different CIA clock speed. Now
NetBSD seems to check for those timers by looking at the default screen
mode under AmigaOS (somthing along those lines anyway). 

So if you've kicked you A3000 into NTSC all the internal timings our out
by about 10% =(


A PAL A3000 should have the following line on boot/in dmesg

clock0 at mainbus0: CIA B system hz 100 hardware hz 709379

If it thinks you have an NTSC model you get

clock0 at mainbus0: CIA B system hz 100 hardware hz 714??? [1]


That /might/ be you problem. It only took me about 9 months to work that
one out, <sigh> =)

If it is you problem then fix that and xntpd will work fine.


[1] Sorry my memory is not *that* good.
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