[ntp:questions] One last release candidate (in name only) and a new -stable

David J Taylor david-taylor at blueyonder.delete-this-bit.and-this-part.co.uk.invalid
Sat Dec 12 16:53:30 UTC 2009

"G8KBV" <> wrote in message 
news:MPG.258dc4812a1f0c84989680 at news.demon.co.uk...
> Hi.
> Can you confirm (or otherwise) the baudrate I need to set my GPS16LVC
> to, to work correctly with Dave Hart's binaries on Windows?  I know the
> default NMEA rate is 4800 (I think) but I want to be sure on this, if
> just to remove one variable for the next stage of my master plan.  Once
> I've found a "happy place" to site the GPS receiver itself.
> Also, how do all the various binaries in the serialpps-yyyymmdd.zip
> files work together, or have I missed a document download somewhere?
> The patched NTPD binaries continue to work OK lan/wan synched at the
> moment.
> Cheers.
> Dave Baxter.


I have my GPS18 LVCs set to 4800 baud for Dave Hart's Windows version.  I 
don't know whether they will work with NTP at other rates.

Serial PPS - I can't be sure what documentation is included - I thought 
there was enough.  The serialpps.sys files are functional replacements for 
the serial.sys driver supplied with Windows, there are both 32-bit and two 
64-bit versions provided.  These live along alongside the existing 
serial.sys drivers, and a registry edit determines which is loaded at boot 
time.  You can swap back just by reverting the registry edit.  Batch files 
are provided to help with the registry edit.

There is only one version of the DLL (32-bit), and ntpd.exe will try to 
call that DLL if a certain environment variable is set.  Dave hart wrote:

There's a new .dll there which ntpd currently finds by way of environment 
variable PPSAPI_DLLS.  If you put it in the same directory as ntpd.exe, 
this should work


you can also use a path:


Keeping it out of the ntpd.exe directory avoids having it stepped on by 
running the Meinberg installer.

but that text isn't in the version I have (serialpps-20090606.zip).  As 
I've mentioned before, on the system I tested which some may say is 
lightly loaded, adding the kernel-mode serialpps.sys routine did make some 
improvement, but not a lot compared to having a PPS-sync rather than a 

David GM8ARV 

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