Re: [ntp:questions] Timekeeping broken on Windows XP with multimedia timer enabled (-M option)
http://www.veracityuk.com/products/timenet/timenet.php http://www.veracityusa.com/products/timenet/timenet.php http://www.gpsntp.com/economic-ntpserver/ Thanks, most interesting - I knew about neither of those products. http://www.veracityuk.com/products/timenet/timenet.php Accuracy: Ethernet NTP ±100ms overall is not what I call good timekeeping. http://www.gpsntp.com/economic-ntpserver/ NTP time stamp resolution: +/- 15 usec - nice that it has SNMP, but no specification of accuracy! You can't buy directly from either site, which discourages an impulse purchase. I already have the GPS, and was looking for a simple computer (small and low-powered) where I could run a FreeBSD or similar system. Will see what emerges from the router or David Lord's approaches. Cheers, David ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Timekeeping broken on Windows XP with multimedia timer enabled (-M option)
Evandro Menezes wrote: On Jan 25, 8:15 am, Martin Burnicki martin.burni...@meinberg.de wrote: Yes, it helps indeed ;-) I'm glad it does. And just for completion, the current generation of AMD processors derive the CPU clock from the memory controller clock instead of the FSB. Moreover, the memory controller clock may also be changed on the fly and is thus subject to power management policies too, effectively making its TSC not invariant if the memory controller power is managed. However, I don't know of any OS that does this yet. Argh, I just began to hope things could become easier in the future. I'm sure the OS maintainers will find a way to fiddle with this to degrade timekeeping ;-) Martin -- Martin Burnicki Meinberg Funkuhren Bad Pyrmont Germany ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Simple but good NTP server
Richard B. Gilbert wrote: If you are talking about REAL routers, they are not cheap. If you are talking about SOHO routers such as sold by LinkSys they are cheap enough but building NTPD to run on one might be fairly difficult. OpenWRT and similar Linux Distributions have binary packages for ntpd. ( And it is not much hassle to set up a crossbuild environment. Well if you are on windows : SOL ) Just about any PC built in the last ten years should be able to run Solaris or Linux and serve time using a GPS reference clock. Those small ARM platforms take about 10W, $ANY x86 PC takes about 100++W. Occupied real estate is quite different too. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Simple but good NTP server
OpenMoko's FreeRunner Hardware could be interesting. GPS, WLAN, USB-Net on Board ( Arm platform, ntpd works out of the box ). http://wiki.openmoko.org/wiki/Neo_FreeRunner_GTA02_Hardware uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Date Jumped
David Woolley da...@ex.djwhome.demon.invalid wrote: Richard B. Gilbert wrote: If I see a notation in code saying, in effect, can't get here I add whatever call means suicide with crash dump if it's not already present. I don't get many crash dumps but if the impossible happens I like to have it documented. In the environment in which I work, that strategy would be totally uncacceptable to Marketing, as it essential that customer systems do not stop dead. I suspect that applies to many politically critical uses of NTP. Logging is desirable, but stopping is not. Note it also was the way in which the first Ariane 5 launch failed. The control system stopped dead because it encountered an overflow in an unimportant calculation. The backup system ran the same code and stopped dead the same way. Sometimes it is simply not clever to handle errors that way. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Timekeeping broken on Windows XP with multimedia timer enabled (-M option)
David J Taylor wrote: http://www.veracityuk.com/products/timenet/timenet.php http://www.veracityusa.com/products/timenet/timenet.php http://www.gpsntp.com/economic-ntpserver/ Thanks, most interesting - I knew about neither of those products. http://www.veracityuk.com/products/timenet/timenet.php Accuracy: Ethernet NTP ±100ms overall is not what I call good timekeeping. http://www.gpsntp.com/economic-ntpserver/ NTP time stamp resolution: +/- 15 usec - nice that it has SNMP, but no specification of accuracy! You can't buy directly from either site, which discourages an impulse purchase. I already have the GPS, and was looking for a simple computer (small and low-powered) where I could run a FreeBSD or similar system. Will see what emerges from the router or David Lord's approaches. I've moved away from using ntp over ethernet as main method for keeping systems in sync. Network and system load along with temperature variations cause relative havoc which I'll see if I can cure using pps from the radioclock. It could be possible to stabilise system clock oscillators but I'm not sure if that is effective or practical on modern pcs and it really involves too much work vs pps via parallel port (last system I purchased has neither serial nor parallel). The ADM5120P may become base for generating a pps signal to be distributed around network via rs422 and possibly 433MHz tx/rx if that doesn't add too much variation. I'm not sure my programming skills are up to this though. I also have a 486dx with a very stable (at least long term) crystal but lacking ram (I still have another 3x 486 but only 40MB ram total to split between four pcs). My order for some D25 connectors from CPC turned up on Friday, D25 hoods + all the extra items I'd added to take value up to give free delivery, but stock discrepancy and no D25 bodies. Anyway I had a search through my rubbish last night and found a couple of connectors. Meanwhile due to cold weather I've had heating turned up and server using Conrad MSF receiver has had periods of much reduced offsets ( 300us), so suspicion that the ttl out from Conrad is on borderline for the rs232 on that server seems confirmed and I'll give parallel port method a try on a different system later this week. David ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Date Jumped
Rob wrote: David Woolley da...@ex.djwhome.demon.invalid wrote: Richard B. Gilbert wrote: If I see a notation in code saying, in effect, can't get here I add whatever call means suicide with crash dump if it's not already present. I don't get many crash dumps but if the impossible happens I like to have it documented. In the environment in which I work, that strategy would be totally uncacceptable to Marketing, as it essential that customer systems do not stop dead. I suspect that applies to many politically critical uses of NTP. Logging is desirable, but stopping is not. Note it also was the way in which the first Ariane 5 launch failed. The control system stopped dead because it encountered an overflow in an unimportant calculation. The backup system ran the same code and stopped dead the same way. Sometimes it is simply not clever to handle errors that way. But then the question becomes how DO you handle errors? A Drop dead halt is not a good way to handle errors if you have some other way. Writing code that can continue following any conceivable error is not a job for the faint hearted! ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Simple but good NTP server
Maarten Wiltink wrote: Why did you get 4801s? I recall reading here that the 4501 was no longer for sale, but Soekris' own website offers them. I didn't get them specifically for timing purposes, but rather to act as a platform on which to build my own access routers (with added DSL and wifi peripherals). Not the cheapest way of doing that (which would be to get a Linksys box and run openwrt), but fun nonetheless. Jan ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Timekeeping broken on Windows XP with multimedia timer enabled (-M option)
David J Taylor wrote: http://www.veracityuk.com/products/timenet/timenet.php http://www.veracityusa.com/products/timenet/timenet.php http://www.gpsntp.com/economic-ntpserver/ Thanks, most interesting - I knew about neither of those products. http://www.veracityuk.com/products/timenet/timenet.php Accuracy: Ethernet NTP ±100ms overall is not what I call good timekeeping. http://www.gpsntp.com/economic-ntpserver/ NTP time stamp resolution: +/- 15 usec - nice that it has SNMP, but no specification of accuracy! You can't buy directly from either site, which discourages an impulse purchase. I already have the GPS, and was looking for a simple computer (small and low-powered) where I could run a FreeBSD or similar system. Will see what emerges from the router or David Lord's approaches. http://www.marvell.com/platforms/plug_computer/ -- E-Mail Sent to this address blackl...@anitech-systems.com will be added to the BlackLists. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
