Accurate time without a network connection?

David Kelly dkelly at
Wed Apr 23 17:58:22 PDT 2003

On Wednesday 23 April 2003 02:30 pm, Arthur W. Neilson III wrote:
> Hey David.  I built a gps clock for ~200 bucks, it's really good.
> It's based on the Motorola UT+ board which is 5" x 3" all SMT and
> prebuilt, this is interfaced to a smaller daughtercard from TAPR
> (Tuscon Amateur Packet Radio club)  I am a ham myself and also
> a freebsd guy since v2.1.2 ... the daughtercard converts the TTL
> PPS (pulse per sec) signal from the gps to rs232 with a MAX232
> chip, you'll need some soldering skills to build the daughtercard,
> connect things together and mount it in the enclosure of your
> choice. Here check it out at my website:
> <>

That is really cool!

I haven't found the ntpd documentation to as useful as it might. Lots of 
documentation in html format in /usr/share/doc/ntp/ but somehow I 
haven't found a table of contents. Eventually found 
file:/usr/share/doc/ntp/howto.htm but your example goes a long way 
toward my understanding.

Many years ago I had a heck of a time with the xntpd documentation until 
I finally figured out only "server hostname" was needed in ntpd.conf. 
Then not too many years ago in a conversation with a friend who has a 
commit bit, learned he too had been stymied by ntpd and was running 
ntpdate from cron every hour or so on his servers. Not any more.

As for the situation which prompted this thread, the worker bees on both 
ends have finally done an end-run around management and are talking 
direct. Apparently we will be allowed an ethernet tap to speak ntp 

As for other fun things I have my GPS sitting in a window trying to get 
a lock. It actually holds a lock about half the time. So I'm starting 
to play with the NMEA clock driver in ntpd.

I may never get around to creating a webcam driver for ntpd. But it 
would be fun.

David Kelly N4HHE, dkelly at
The human mind ordinarily operates at only ten percent of its
capacity -- the rest is overhead for the operating system.

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