Subject: Re: date and time
To: Paul Sander <paul@wakawaka.com>
From: Henry B. Hotz <hotz@jpl.nasa.gov>
List: port-mac68k
Date: 02/02/2000 14:16:57
What most people do is run ntpdate in a cron entry.  I've heard from one
person who said he got xntp to run OK, but I never have and so I wouldn't
expect it to work in general on the Mac68k architecture.

At 11:00 PM -0800 2/1/00, Paul Sander wrote:
>I was just wondering (in a vacuum, because I haven't read the code or
>understand the design of the kernel in any detail):  Isn't there some way
>to give the clock a very high priority interrupt that does nothing but
>increment a counter, and periodically read that counter and update the
>clock accordingly?  One would think the overhead of such a thing would

Yes, there's the rub.  That's basically how NetBSD is *supposed* to work.

The problem is a basic philosophical decision made when the first Mac's
were designed:  The most important task of the machine was the user
interface, therefore the mouse is highest priority, etc, etc.  The timer
interrupt is lowest priority and you can't change it.

Except that some models like the C/Q650 have an alternate priority order
which was put in to improve A/UX support.  Some work has been done to
enable it in NetBSD, but I haven't heard it's there yet.

BTW, the problem with reading/sync'ing to the hardware clock is that you
can only read it to the nearest second, or so I've heard.  Pretty poor
resolution for ntp.

Signature failed Preliminary Design Review.
Feasibility of a new signature is currently being evaluated.
h.b.hotz@jpl.nasa.gov, or hbhotz@oxy.edu