CHRIS@COLUMBIA-20.ARPA (09/09/84)
From: Chris Maio <CHRIS@COLUMBIA-20.ARPA> Can anyone point me to programs for 4.2bsd to poll the net for the time at system startup, and a companion daemon to service those requests? TCP would be preferred, but UDP is ok too. Thanks. - Chris -------
rusty@sdcc3.UUCP (09/11/84)
someone just told me that heathkit is making a device that listens on the various frequencies that have the time transmitted on them. i don't know what frequencies these are. if you have a radio with some shortwave bands you may have come across one; you hear a sort of blipping tone and then every so often (once a second i think) you hear a man's voice give the time. it is given in what used to be called greenwich mean time (now its called universal something or other). the time reference they are using is an atomic clock. these broadcasts are by the national bureau of standards. anyhow, back to this heathkit device; it has an rs232 connection on it. it is designed to be hooked up to a computer. i guess one of these frequencies has the time transmitted in a way that can be decoded by a computer? i guess you can have your computer ask it every so often what time it is, or maybe the heathkit box spits out the time on the rs232 connection every so often. i have no idea about the format of the data into or out of of the rs232 connector. so, what i was thinking is that if you get a time server going you might want to get one of these gizmos.
rusty@sdcc3.UUCP (09/11/84)
i think i meant once a minute instead of once a second (don't think he could talk that fast).
rpw3@redwood.UUCP (09/13/84)
Although there was some talk about discontinuing it (due to local abuse),
for long-distance users at least, the following number in Boulder, CO,
(NOT toll-free) gets you the WWV baseband signal (beeps, clicks, time
announcements on the minute, etc.):
(303)499-7111
As far as I know, this is exactly the same as what goes out over the air.
Do NOT try to use this for precision work, as your long-distance call
may be delayed several milliseconds; it seems fine for checking your local
phone company time number for being "right on" or "sloppy". (The Pacific
Bell number(s) in the Bay Area [767-xxxx, also known as "POPCORN"] seem
to be "right on".)
Note that there is a published standard for how to decode these things
automatically (I saw a version in an Electronic Engineering Handbook).
Little things like the "tick" on the 59th second being delayed (the "ticks"
are really 5 cycles of a 5000 Hertz tone), etc. I suppose NBS would send
you an "official" one if you asked.
Rob Warnock
UUCP: {ihnp4,ucbvax!amd}!fortune!redwood!rpw3
DDD: (415)369-7437
Envoy: rob.warnock/kingfisher
USPS: Suite 203, 4012 Farm Hill Blvd, Redwood City, CA 94061henry@utzoo.UUCP (Henry Spencer) (09/17/84)
> someone just told me that heathkit is making a device that listens on > the various frequencies that have the time transmitted on them... It's the pretentiously-named "Most Accurate Clock". We've got one. The only thing you need to watch is that if your reception for the WWV time signal isn't good, you're in trouble -- the clock has neither battery backup nor a manual-set procedure, so it *must* pick up WWV well if you want it to function properly immediately after a power outage. -- Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,linus,decvax}!utzoo!henry