[time-nuts] Set time on Solaris computer from HP 58503A

Chris Albertson albertson.chris at gmail.com
Sun Dec 14 13:30:25 EST 2014

I would still like to experiment with it. As I wrote earlier I bought this
> for a frequency reference,  not a clock, but I would not object to a bit of
> fun messing around with it.
If the goal is just getting good enough time onto the Solaris machine then
use NTP and some pool servers on the Internet.  You get about 10
millisecond level accuracy and the cost is zero.  If you have solaris
running you might even have this all setup and running.  If not do this as
the first step and verify it works.

If 10ms is unacceptable, next step is to connect the PPS signal.  Doing
this will move you from milli to micro second level accuracy.   It is easy
if the Solaris machine has a real serial port.   If you have to go through
a USB dongle you loose about an order of magnitude accuracy but this is
still very good.

There is zero point in buying a special computer to run NTP.  Just use any
computer you own that is already running 24x7.  Of course if you don't have
a computer that runs 24x7 then you would look for one that uses very little

Don't worry to much if the USB connection skews the time on the NTP server
by some tens of microseconds, your server can't transfer time to your other
computers on the LAN any better than millisecond level so a few tenths of
an millisecond hardly mater.

My opinion of computer time is that for normal use being a few milliseconds
off is OK because the typical monitor is refreshed no faster than 100Hz so
you have lag cause by screen refresh times even if the internal clock is
dead-on perfect.  Same for disk time stamps, these is lag in the IO system


Chris Albertson
Redondo Beach, California

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