Richard Laager said: > I believe Hal is incorrect. NTPsec has not removed this driver. It's the > "modem" driver. Thanks for the correction. Does anybody have any data? How well does it work these days? What do I need in the way of a modem or PCI card so that I can test/use that driver and service? Will an old modem from eBay work if I plug it into the phone socket on the side of my internet phone box? Are there any models or buzzwords to get or avoid? -- These are my opinions. I hate spam.

Hi Traditionally, the gotcha with doing it dial up was getting the timing somewhere near close to correct. The obvious stuff internal to the PC is similar to what you go through with a PPS input. With a serial port, you don’t have an interrupt based on an edge. This makes things a bit more convoluted. The modem side of things also has delays. Working out just what they are is a bit exciting. Like a lot of things, you got it close and then moved on. You then have telecom network delays. This is fundamentally the same as internet delays. All of the stuff above can be / is / might be asymmetric. most cases all the delays turned out to be a bit variable. In an era of tenth second timing, that probably was not a big deal. These days with GPS giving you < 1 us the competition is in a different league. You have the same sort of issue with WWVB. The driver needs to know the propagation delay. One high profile public server in PA ran WWVB and got the sign on the delay backwards. Not a good thing ……Since the delay varies night vs day, you would pick one or the other. That might have changed in newer drivers. Yes, all that info is a bit dated…… Bob > On Sep 13, 2022, at 12:48 PM, Hal Murray via time-nuts <time-nuts@lists.febo.com> wrote: > > > Richard Laager said: >> I believe Hal is incorrect. NTPsec has not removed this driver. It's the >> "modem" driver. > > Thanks for the correction. > > Does anybody have any data? How well does it work these days? > > What do I need in the way of a modem or PCI card so that I can test/use that > driver and service? > > Will an old modem from eBay work if I plug it into the phone socket on the > side of my internet phone box? Are there any models or buzzwords to get or > avoid? > > > > -- > These are my opinions. I hate spam. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-leave@lists.febo.com