OT: Alternative clock display

Terry Pinnell · Jun 7, 2005

Makes a change from those boring LED displays...
http://www.lares.dti.ne.jp/~yugo/storage/monocrafts_ver3/03/

....but, after about a minute, not a welcome change!

BTW, time is correct here (Timezone = GMT, currently plus 1 hour
Daylight Saving Time); how is it for others?

--
Terry Pinnell
Hobbyist, West Sussex, UK
Tue 7 June 2005, 13:12 UK time

Frank Bemelman · Jun 7, 2005

"Terry Pinnell" <terrypinDELETE@THESEdial.pipex.com> schreef in bericht
news:ki3ba1l6qslkt71odvsvpj9ib0jbghdknr@4ax.com...

Makes a change from those boring LED displays...
http://www.lares.dti.ne.jp/~yugo/storage/monocrafts_ver3/03/

...but, after about a minute, not a welcome change!

BTW, time is correct here (Timezone = GMT, currently plus 1 hour
Daylight Saving Time); how is it for others?

The script uses your own PC's clock - you can set it at any
time you want.

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

Joerg · Jun 7, 2005

Hello Guy,

Here is one that gives you the actual time instead of parroting
your computer's clock:

[ http://tycho.usno.navy.mil/cgi-bin/anim ]

Just tried and it was two seconds late versus WWVB. I don't think
accurate time can be sent via the web.

Regards, Joerg

http://www.analogconsultants.com

John Devereux · Jun 7, 2005

Joerg <notthisjoergsch@removethispacbell.net> writes:

Hello Guy,

Here is one that gives you the actual time instead of parroting
your computer's clock:
[ http://tycho.usno.navy.mil/cgi-bin/anim ]

Just tried and it was two seconds late versus WWVB. I don't think
accurate time can be sent via the web.

I think you will find it can; google for ntp!

--

John Devereux

Jim Thompson · Jun 7, 2005

On Tue, 07 Jun 2005 17:22:00 -0400, Spehro Pefhany
<speffSNIP@interlogDOTyou.knowwhat> wrote:

On Tue, 07 Jun 2005 21:02:19 GMT, the renowned Joerg
notthisjoergsch@removethispacbell.net> wrote:

Hello Guy,

Here is one that gives you the actual time instead of parroting
your computer's clock:

[ http://tycho.usno.navy.mil/cgi-bin/anim ]

Just tried and it was two seconds late versus WWVB. I don't think
accurate time can be sent via the web.

Regards, Joerg

http://www.analogconsultants.com

I had one (didn't need it so I uninstalled it) that would measure the
round trip time to a time server, divide by two, and compensate. The
round trip time was typically in the tens of msec.

Best regards,
Spehro Pefhany

480)460-2350 | |
| E-mail Address at Website Fax

Spehro Pefhany · Jun 7, 2005

On Tue, 07 Jun 2005 21:02:19 GMT, the renowned Joerg
<notthisjoergsch@removethispacbell.net> wrote:

Hello Guy,

Here is one that gives you the actual time instead of parroting
your computer's clock:

[ http://tycho.usno.navy.mil/cgi-bin/anim ]

Just tried and it was two seconds late versus WWVB. I don't think
accurate time can be sent via the web.

Regards, Joerg

http://www.analogconsultants.com

I had one (didn't need it so I uninstalled it) that would measure the
round trip time to a time server, divide by two, and compensate. The
round trip time was typically in the tens of msec.

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

Frank Bemelman · Jun 7, 2005

"Joerg" <notthisjoergsch@removethispacbell.net> schreef in bericht
news:vXnpe.25572$J12.44@newssvr14.news.prodigy.com...

Hello Guy,

Here is one that gives you the actual time instead of parroting
your computer's clock:

[ http://tycho.usno.navy.mil/cgi-bin/anim ]

Just tried and it was two seconds late versus WWVB. I don't think
accurate time can be sent via the web.

The network itself is pretty fast, it has to be -> if it
were slow all the data/traffic had to sit/wait in large
fifo buffers. That would not make sense.

If you notice a delay, it is often the server not responding
fast enough, or just too much traffic at certain nodes and
data being thrown away. The upper layers of the protocols
will retry, but then things slow down immensely.

Yet I'm always surprised when a simple ping gives a nice list
of respond times of tens of milliseconds, and even more
surprised when Google spits a full screen almost *before* I
have even touched the enter key... as if they knew what I
was going to ask

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

Guy Macon · Jun 7, 2005

Joerg wrote:

Hello Guy,

Here is one that gives you the actual time instead of parroting
your computer's clock:

[ http://tycho.usno.navy.mil/cgi-bin/anim ]

Just tried and it was two seconds late versus WWVB. I don't think
accurate time can be sent via the web.

Interesting. Any chance that there is a proxy or firewall between
you and the web? I could easily believe a sizable fraction of a
second because of the internet, but 2 seconds seems too high.
Even bouncing off a geosynchronous satellite only adds a qurter of
a second or so.

John Perry · Jun 7, 2005

Jim Thompson wrote:

On Tue, 07 Jun 2005 17:22:00 -0400, Spehro Pefhany
speffSNIP@interlogDOTyou.knowwhat> wrote:

On Tue, 07 Jun 2005 21:02:19 GMT, the renowned Joerg
notthisjoergsch@removethispacbell.net> wrote:

Hello Guy,

Here is one that gives you the actual time instead of parroting
your computer's clock:

[ http://tycho.usno.navy.mil/cgi-bin/anim ]

Just tried and it was two seconds late versus WWVB. I don't think
accurate time can be sent via the web.

Regards, Joerg

http://www.analogconsultants.com

I had one (didn't need it so I uninstalled it) that would measure the
round trip time to a time server, divide by two, and compensate. The
round trip time was typically in the tens of msec.

Best regards,
Spehro Pefhany

I use SocketWatch...

http://www.locutuscodeware.com/swatch.htm

...Jim Thompson

....How about a full-featured SNTPv4 time setting utility:

http://oneguycoding.com/automachron/

fully free, allows a large selection of NTP servers, keeps track of your
PC's errors, sets the time to within milliseconds, tells you how far off
your setting is (my wife's is usually within 50ms after a sync), ...

Almost as good as the real OS time-sync utilities

.

John Perry

Guy Macon · Jun 7, 2005

Spehro Pefhany wrote:

I had one (didn't need it so I uninstalled it) that would measure the
round trip time to a time server, divide by two, and compensate. The
round trip time was typically in the tens of msec.

Here is an interesting survey of over 175,000 hosts NTP servers.
[ http://xenia.media.mit.edu/~nelson/research/ntp-survey99/html/ ].
10% of the hosts were off by more than 20ms, 1% by more than 1s,
and a few are off by up to a full year (!).

I seriously doubt that tycho.usno.navy.mil is off by even a 1ms...)

Joerg · Jun 7, 2005

Hello Spehro,

I had one (didn't need it so I uninstalled it) that would measure the
round trip time to a time server, divide by two, and compensate. The
round trip time was typically in the tens of msec.

It you don't need fractions of a second in accuracy it could work. But
when I looked at round trip to some servers outside California I found
that the times jumped up and down rather erratically. Up to 200msec.

Regards, Joerg

http://www.analogconsultants.com

Joerg · Jun 7, 2005

Hello Frank,

The network itself is pretty fast, it has to be -> if it
were slow all the data/traffic had to sit/wait in large
fifo buffers. That would not make sense.

Well, it does have to sit in buffers for any realtime stuff. I used to
listen to Deutsche Welle radio on the web occasionally. Not in the last
6 months though because it kept cutting out despite several seconds of
local buffering. And this was 64kbps or so over my >1Mbps connection.
Shortwave doesn't have that problem, neither for radio nor for the time
signal. Yes, the path lengths change but they do that much slower than
the web.

Also, all it takes to make it unreliable is some hacker who spoofs
traffic and brings part of the web to a crawl. T'has happened.

Regards, Joerg

http://www.analogconsultants.com

Joerg · Jun 7, 2005

Hello Guy,

Interesting. Any chance that there is a proxy or firewall between
you and the web? ...

Yes, hardware. But disabling that would be the same as leaving your door
unlocked when going to work. A neighbor supposedly did that and regrets
it badly now.

...I could easily believe a sizable fraction of a
second because of the internet, but 2 seconds seems too high.
Even bouncing off a geosynchronous satellite only adds a qurter of
a second or so.

Yes, usually I see between 10msec and 200msec. But what good does it do
if you have to disable a firewall to take advantage of a web based time
signal?

Regards, Joerg

http://www.analogconsultants.com

Guy Macon · Jun 8, 2005

Frank Bemelman wrote:

Joerg schreef ...

Hello Guy,

Here is one that gives you the actual time instead of parroting
your computer's clock:

[ http://tycho.usno.navy.mil/cgi-bin/anim ]

Just tried and it was two seconds late versus WWVB. I don't think
accurate time can be sent via the web.

The network itself is pretty fast, it has to be -> if it
were slow all the data/traffic had to sit/wait in large
fifo buffers. That would not make sense.

If you notice a delay, it is often the server not responding
fast enough, or just too much traffic at certain nodes and
data being thrown away. The upper layers of the protocols
will retry, but then things slow down immensely.

I thought that too, but such delays really can't explain why
[ http://tycho.usno.navy.mil/cgi-bin/anim ] would be two seconds
off. If you look at the traffic, once the page is loaded it
sends a handful of bytes once per second, regular as clockwork.
It's hard to come to any conclusion other than tycho.usno.navy.mil
sending late or whatever Joerg is using to detect WWVB being early.
(The latter is remotely plausable if he is using one of those low-
cost "atomic clocks", impossible if he is listening to it.)

Mike Monett · Jun 8, 2005

Joerg wrote:

[...]

Yes, usually I see between 10msec and 200msec. But what good does it do
if you have to disable a firewall to take advantage of a web based time
signal?

Regards, Joerg

NIST has link to info on firewalls on their time server page:

http://www.boulder.nist.gov/timefreq/service/its.htm

Mike Monett

Tim Hubberstey · Jun 8, 2005

Jim Thompson wrote:

On Tue, 07 Jun 2005 17:22:00 -0400, Spehro Pefhany
speffSNIP@interlogDOTyou.knowwhat> wrote:

I had one (didn't need it so I uninstalled it) that would measure the
round trip time to a time server, divide by two, and compensate. The
round trip time was typically in the tens of msec.

I use SocketWatch...

http://www.locutuscodeware.com/swatch.htm

If you're running Windows 2000 (and probably XP), there is an NTP client
built into the OS (called W32time, IIRC). All you need to do is enable
it and point it at a server.
--
Tim Hubberstey, P.Eng. . . . . . Hardware/Software Consulting Engineer
Marmot Engineering . . . . . . . VHDL, ASICs, FPGAs, embedded systems
Vancouver, BC, Canada . . . . . . . . . . . http://www.marmot-eng.com

Frank Bemelman · Jun 8, 2005

"Joerg" <notthisjoergsch@removethispacbell.net> schreef in bericht
news:HIppe.25605$J12.8501@newssvr14.news.prodigy.com...

Hello Frank,

The network itself is pretty fast, it has to be -> if it
were slow all the data/traffic had to sit/wait in large
fifo buffers. That would not make sense.

Well, it does have to sit in buffers for any realtime stuff. I used to

Very small buffers, not so much to preserve data packets, but just to
give the router/switch some time to figure out to which output port it
will send the data packet(s). When there's too much input to route to a
given output, data gets lost. At least that is my mental model of
routers - I could be wrong. Perhaps modern router do have very large
buffers, but as I see it, this would only delay the approaching overflow
a bit and therefore not worth trying to prevent it.

listen to Deutsche Welle radio on the web occasionally. Not in the last
6 months though because it kept cutting out despite several seconds of
local buffering. And this was 64kbps or so over my >1Mbps connection.
Shortwave doesn't have that problem, neither for radio nor for the time
signal. Yes, the path lengths change but they do that much slower than
the web.

Your connection may have enough bandwidth, but other sections of the
entire route may not.

Also, all it takes to make it unreliable is some hacker who spoofs
traffic and brings part of the web to a crawl. T'has happened.

Yes, I don't think there is a mechanism to claim guaranteed bandwidth
on the public internet

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

Jim Thompson · Jun 8, 2005

On Wed, 08 Jun 2005 04:10:44 GMT, Tim Hubberstey <bogus@bogusname.com>
wrote:

Jim Thompson wrote:

On Tue, 07 Jun 2005 17:22:00 -0400, Spehro Pefhany
speffSNIP@interlogDOTyou.knowwhat> wrote:

I had one (didn't need it so I uninstalled it) that would measure the
round trip time to a time server, divide by two, and compensate. The
round trip time was typically in the tens of msec.

I use SocketWatch...

http://www.locutuscodeware.com/swatch.htm

If you're running Windows 2000 (and probably XP), there is an NTP client
built into the OS (called W32time, IIRC). All you need to do is enable
it and point it at a server.

480)460-2350 | |
| E-mail Address at Website Fax

Joerg · Jun 8, 2005

Hello Mike,

NIST has link to info on firewalls on their time server page:

http://www.boulder.nist.gov/timefreq/service/its.htm

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

http://www.analogconsultants.com

Tim Hubberstey · Jun 8, 2005

Jim Thompson wrote:

On Wed, 08 Jun 2005 04:10:44 GMT, Tim Hubberstey <bogus@bogusname.com
wrote:

If you're running Windows 2000 (and probably XP), there is an NTP client
built into the OS (called W32time, IIRC). All you need to do is enable
it and point it at a server.

All I can find on my Win2K system is w32time.dll

How do you use it?

Socketwatch queries multiple servers. It's presently showing 11
active servers.

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

OT: Alternative clock display

Terry Pinnell

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Frank Bemelman

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Joerg

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John Devereux

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Jim Thompson

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Spehro Pefhany

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Frank Bemelman

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Guy Macon

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John Perry

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Guy Macon

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Joerg

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Joerg

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Joerg

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Guy Macon

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Mike Monett

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Tim Hubberstey

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