PPSkit-0.3.9 for Linux 2.0.36

Ulrich Windl wrote on linux-kernel:

I’ve updated the PPSkit for Linux 2.0.36. This is an important
update, because I finally tamed the 200us jitter on the PPS signal
that prevented any reasonable work! I strongly advise any
PPSkit-0.3 users to update. (Linux 2.2 does not have this

If you want to verify the jitter quick, easy and dirty, you
could use “enable_pps -j -k Remaining problems are the receive
timestamps wandering around, and finally wrapping at the end of a
time tick, and sometime no PPS pulses are detected on the first
open after reboot (I’m using loadable modules for the serial

Along with this fix come a few other cleanups (similar to those
in the 0.5 version)

So, as usual, here is the NEWS and the LSM.


P.S.: Just in time for the CeBIT 😉

NEWS for 0.3.9

  • Stole a piece of Pentium timing code from Linux-2.2 to avoid
    the jitter of 200us that makes the PPS signal unusable. This fix
    replaces the patch for “Completely Mad Time”.
  • Updated `enable_pps.c’ from PPSkit-0.6. Updated example
    configuration file for xntpd (3-5.93, used for testing)
  • Improved accuracy of `hardware_pps()’ by getting the correct
  • Made `TIME_ERROR’ less sticky, and relax some restrictions of
    `adjtimex()’. Ignore the bug that has to do with
  • This release is actually a branch release, because the actual
    development is at 0.6 (Linux 2.2) now. Don’t expect exciting new
    stuff here.
Title:          PPSkit
Version:        0.3.9
Entered-date:   1999-03-14
Description:    NTP PPS support (and other time patches) for Linux 2.0.36+
                (kernel patch, documentation, test programs)
Keywords:       NTP, PPS, kernel, xntp, time, pulse-per-second,
                synchronization, adjtimex
Author:         [email protected] (Ulrich Windl)
Maintained-by:  [email protected] (Ulrich Windl)
Primary-site:   linux.kernel.org /pub/linux/daemons/ntp/PPS
                37kB PPSkit-0.3.9.tar.gz
Original-site:  pcphy4.physik.uni-regensburg.de /pub/wiu09524/PPS
Platform:       RS232-compatible precision pulse-per-second with an error
                less than 200ppm (0.0002%, 0.2ms)
Copying-policy: GPL, but payment welcome!