OT: Alternative clock display

Hello Mike,

Thanks. I found the firewall hints. The gist is that it must be opened for outbound connection. Nah, I'd rather stay with WWVB and the clock is just a few feet from my desk. Keeping things simple ;-)

Regards, Joerg

Sorry, I don't remember the exact process for setting it up. I'll tell you what I remember.

1. w32time.dll runs as a service named "Windows Time". In addition to syncing with a NTP server, it also figures out a fudge factor for your PC's clock and applies it to maintain accuracy between server queries. Find it in the Admin Tools -> Services tool and change the startup type to "Automatic".
2. Open a DOS box and type: NET TIME /SETSNTP[:ntp server list]

You may need to reboot to have this take effect. If things are working, you should have registry entries something like this:

[HKEY_LOCAL_MACHINE\\SYSTEM\\CurrentControlSet\\Services\\W32Time\\Parameters] "LocalNTP"=dword:00000000 "Period"="SpecialSkew" "type"="NTP" "ntpserver"="timelord.uregina.ca" "Adj"=dword:0001873c "msSkewPerDay"="603.0000"

There is a white paper on setting up the service on the Micro$oft website. I think I found it by searching for NTP or SNTP. There is also documentation in the Windows help system.

I was using the US Navy NTP server (TICK/TOCK...), but I found it to be very unreliable. It is possible (and not unreasonable) that it was filtering out-of-country requests so YMMV.

It was a bit of a pain to setup initially, but it has been chunking along without intervention for quite a while now.

--
Tim Hubberstey, P.Eng. . . . . . Hardware/Software Consulting Engineer
Marmot Engineering . . . . . . .  VHDL, ASICs, FPGAs, embedded systems
Vancouver, BC, Canada  . . . . . . . . . . . http://www.marmot-eng.com

Yep. If it ain't broke, don't fix it.

However, you might want to verify that it keeps the PC clock adjusted between server queries. Sudden time changes can really screw up some build processes, with "interesting" results. If your PC clock runs slow, it's not usually an issue, but if it runs fast and gets set back, watch out! This is why Sun boxes allow you to speed up or slow down the clock to change the time.

--
Tim Hubberstey, P.Eng. . . . . . Hardware/Software Consulting Engineer
Marmot Engineering . . . . . . .  VHDL, ASICs, FPGAs, embedded systems
Vancouver, BC, Canada  . . . . . . . . . . . http://www.marmot-eng.com

Hello Guy,

Well, both. The atomic clock was low cost, about $20. But it perfectly corroborates the WWV time signal on 15MHz. The signal via the web was again about two seconds late this morning, right now it is a little over one second late.

We do use a HW firewall, maybe that has indeed something to do with it. Also, I did not use any SW that performs latency averaging.

Regards, Joerg

I expect if you ask NIST, that web page is intended as a concept / gimmick / demo. It'd be highly susceptible to rendering delays in your browser, which is what you're probably seeing.

The page is actually pretty clever under the hood. It's a multi-part MIME document - each second, the server sends the next part, which is configured to overlay the prior page in-place. It looks like a reloading page, but it's really one page that takes 31 seconds to load fully. Each block of info is small enough to fit a single packet, and there wouldn't be a perceptable delay in the Internet transport.

For a simple real-time check, try this one: telnet time-a.timefreq.bldrdoc.gov 13 Info at

Cheers, Richard

Well, my home firewall (Netgear RP614v2) offers "port forwarding", which sounds like what Microsoft is telling you, and "port triggering".

They describe forwarding as opening the port permanently for outside access. I don't blame you, I wouldn't do this, either.

Port triggering, on the other hand, allows computers inside the firewall to open a port for a limited time, so that outsiders (ntp servers) can get through for the limited period.

Their minimum opening is 1 minute, which makes me a bit uneasy; on the other hand, after the minute, it's closed tight again. I wish the minimum limit were shorter, but I expect (hope?) it would take longer than a minute for a hacker to get control of even my wife's XP machine.

Of course, we run other intrusion checks, too.

John Perry

Hello Frank,

No, as I said I compared it with WWVH this morning and this afternoon. Both times it was right on and WWVH is realtime, with voice announcing and all. There is a delay because of the shortwave path but that is minimal.

Regards, Joerg

Impossible. He said he listened to the WWV time signal on 15MHz. There is a slight delay because of the speed of light from WWV to his antenna, a slight delay because of the speed of sound from his speaker to his ear, then whatever error his nervous system has when comparing audio and visual events. All far less than a second, and not able to make the signal come early.

So we have narrowed it down to five possibilities:

[1] tycho.usno.navy.mil, home of the US Naval Observatory Master Clock (based on dozens of independently operating cesium atomic clocks and a dozen hydrogen maser clocks [ ] and the primary reference for the GPS system), is off by 2 seconds one day and one second the next, and nobody has noticed that the GPS system is giving answers that are off by many thousands of miles. [2] WWV, which is derived from the USNO master clock as well, is off by 2 seconds one day and one second the next and only one of the many, many people who listen to WWV has noticed this. [3] Joerg is an alien invader and his interstellar fleet was two light seconds away yesterday and one light-second away today, but for some reason having to do with alien technology he can hear WWV with no delay. [4] Rich is pretending to be Joerg and is laughing at us as we puzzle over this clever deception of his. [5] There can be a 1-2 second delay between tycho.usno.navy.mil updating it's webpage and Joerg's browser displaying the change, and I and others were wrong about how big delays through the Internet can get.

"Joerg" schreef in bericht news:DiIpe.1338$ snipped-for-privacy@newssvr21.news.prodigy.com...

Maybe your WWV(B?) clock is early. These clocks only try to synchronize once a day, typically around midnight. The rest of the day the clock runs on a poorly calibrated crystal, easily loosing seconds per day. You might want to check by removing the batteries, and reinserting them and wait until it synchronizes again.

Don't think that would make a difference.

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Thanks, Frank.
(remove \'q\' and \'invalid\' when replying by email)

Any idea why the rendering delay might be 2 seconds one day and 1 second the next?

I just looked at it using a 56K modem on a 100Mhz 486 running W2K, testing with IE, Firefox, and Opera, and the digits seemed to be changing on my screen at the same time the data light on the modem would blink.

--
Steve Sousa

Hello Richard,

Thanks. I had looked at that but it requires to install SW. Since it is from NIST I trust the SW but I'll have to wait a couple weeks or so for enough time to do it and test it.

Regards, Joerg

Hello John,

That is exactly where my concerns start. One minute is plenty of time if some kid were to hog traffic along the path and just sit and wait for all the openings from gazillions of users that fly by. I'd rather not.

One minute is plenty of time access your PC and compromise it.

Regards, Joerg

It's showing my system clock time, which is set to Pacific Daylight Time.

I got lucky and got to see it change from 07:59:59 to 08:00:00. Kinda busy! :-)

Cheers! Rich

On Thu, 09 Jun 2005 00:46:32 +0000, Guy Macon wrote: ...

"Ticking away the moments that make up a dull day You fritter and waste the hours in an off hand way Kicking around on a piece of ground in your home town Waiting for someone or something to show you the way ..."

;-)

Cheers! Rich

I figure, as long as it's close enough that I don't miss lunch, it's good enough. ;-)

Cheers! Rich

The last time I tried to install Windows 2000 with an open connection, I got hacked before I even had time to run "windows update" - i.e., it seemed like a matter of seconds. I think the hackers have bots going 24/7 - you can poll an awful lot of IPs in a minute!

Cheers! Rich

Hello Rich,

And crooks can install an awful lot of spyware in that time. If the port is opened regularly for 1-minute intervals that seems to be comparable to leaving your house keys on top of the mail box. Well, not in our case because then there are two large dogs to negotiate entry with but they won't protect the Internet link.

Regards, Joerg

Ummm... this uses telnet... :-)

Telnet to port 13 on telnet time-a.timefreq.bldrdoc.gov... you'll get back:

53532 05-06-11 04:10:01 50 0 0 533.0 UTC(NIST) *

The command-line syntax is commonly: telnet time-a.timefreq.bldrdoc.gov 13

Format info at the URL above.

Cheers, Richard