[aprssig] Com port SHARING vs Com Port JOINING

Ray McKnight shortsheep at worldnet.att.net
Tue Jan 15 01:15:21 EST 2008

> My desire here is to use a Garmin GPS receiver to feed data to a 
> DeLorme Street Atlas program and at the same time feed the GPS data to 
> a program that would keep the computer (a Dell Latitude laptop) time 
> correct. I have found an inexpensive program that will set the 
> computer's time using GPS data, but it does not share access to the 
> COM port.

Also, most folks don't realize that "GPS Time" is NOT
Earth time!  The GPS constellation does not follow leap seconds.
This has happened something like 13 times, so GPS time is off by
About that much from official "Earth Time".  Merely using a GPS
To update your computer's CMOS clock will not make your computer's
Time "correct".  A GPS is generally a fantastic tool for a time
"reference", like a 1ppm time base standard, but it's not an earth
clock.  You probably will be much better off simply using a NTP
utility to update the computer time from the Internet, such as
"SocketWatch 32" (www.locutuscodeware.com).

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