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1*abb0f93cSkardelHP e3000 MPE/iX NTP Hints - May 29, 2001
2*abb0f93cSkardel----------------------------------------
3*abb0f93cSkardel
4*abb0f93cSkardelNTP was first ported to MPE several years ago, but those diffs were never
5*abb0f93cSkardelsubmitted back to the official NTP distribution.  For more information about
6*abb0f93cSkardelthat deprecated port, please see http://www.bixby.org/mark/xntpix.html.
7*abb0f93cSkardel
8*abb0f93cSkardelNTP was re-ported to MPE in May 2001.  What follows are hints learned from
9*abb0f93cSkardelworking with NTP 4.0.99k23.  For additional information about NTP on MPE,
10*abb0f93cSkardelplease see http://jazz.external.hp.com/src/hp_freeware/ntp/.
11*abb0f93cSkardel
12*abb0f93cSkardelMPE lacks the clock-related APIs expected by NTP, so adjtime(), gettimeofday(),
13*abb0f93cSkardeland settimeofday() all had to be implemented from scratch by calling
14*abb0f93cSkardelprivileged, undocumented internal OS functions.
15*abb0f93cSkardel
16*abb0f93cSkardelUnfortunately the implementation of adjtime() has exposed a sub-second accuracy
17*abb0f93cSkardelbug when slewing the system time.  This bug is documented in SR 5003462838, and
18*abb0f93cSkardelexists on all current versions of MPE.  It has not been fixed at the time of
19*abb0f93cSkardelthis writing.  The adjtime() code may possibly need to be altered if/when this
20*abb0f93cSkardelbug is fixed.
21*abb0f93cSkardel
22*abb0f93cSkardelThis bug has a side-effect whereby the ntpd daemon will screw up the hardware
23*abb0f93cSkardelPDC clock time by many minutes if used for continuous clock adjustments or in
24*abb0f93cSkardelthe one-time -q mode.  But note that you can safely run ntpd in order to become
25*abb0f93cSkardela time server if you include "disable ntp" in the ntp.conf configuration file.
26*abb0f93cSkardel
27*abb0f93cSkardelThe one-time clock adjustment functionality of ntpdate and ntp_timeset is not
28*abb0f93cSkardelaffected by this bug side-effect.  You can safely use these commands to alter
29*abb0f93cSkardelyour system time with reasonable accuracy.
30*abb0f93cSkardel
31*abb0f93cSkardelThe only reference clock that has been tested on MPE is the local clock.  So
32*abb0f93cSkardelbuilding NTP with --disable-all-clocks --enable-LOCAL_CLOCK is strongly
33*abb0f93cSkardelrecommended.
34*abb0f93cSkardel
35*abb0f93cSkardelNTP makes use of Privileged Mode (PM) capability in order to bind to the NTP
36*abb0f93cSkardelnetwork port (123) and to access the low-level clock functions.
37*abb0f93cSkardel
38*abb0f93cSkardelNTP was ported using the gcc compiler.  Attempting to use the HP C/iX compiler
39*abb0f93cSkardelis not recommended and has not been tested.
40*abb0f93cSkardel
41*abb0f93cSkardelPlease note that NTP is not an HP product and is NOT supported by HP.  The best
42*abb0f93cSkardelplace for asking MPE-specific questions about NTP is the HP3000-L mailing list
43*abb0f93cSkardelat http://raven.utc.edu/Archives/hp3000-l.html or the associated Usenet
44*abb0f93cSkardelnewsgroup of comp.sys.hp.mpe.
45*abb0f93cSkardel
46*abb0f93cSkardelThe original author of this port is:
47*abb0f93cSkardel
48*abb0f93cSkardelMark Bixby
49*abb0f93cSkardelHP CSY MPE Internet & Interoperability Engineer
50*abb0f93cSkardelmark_bixby@hp.com
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