HP e3000 MPE/iX NTP Hints - May 29, 2001----------------------------------------NTP was first ported to MPE several years ago, but those diffs were neversubmitted back to the official NTP distribution.  For more information aboutthat deprecated port, please see http://www.bixby.org/mark/xntpix.html.NTP was re-ported to MPE in May 2001.  What follows are hints learned fromworking with NTP 4.0.99k23.  For additional information about NTP on MPE,please see http://jazz.external.hp.com/src/hp_freeware/ntp/.MPE lacks the clock-related APIs expected by NTP, so adjtime(), gettimeofday(),and settimeofday() all had to be implemented from scratch by callingprivileged, undocumented internal OS functions.Unfortunately the implementation of adjtime() has exposed a sub-second accuracybug when slewing the system time.  This bug is documented in SR 5003462838, andexists on all current versions of MPE.  It has not been fixed at the time ofthis writing.  The adjtime() code may possibly need to be altered if/when thisbug is fixed.This bug has a side-effect whereby the ntpd daemon will screw up the hardwarePDC clock time by many minutes if used for continuous clock adjustments or inthe one-time -q mode.  But note that you can safely run ntpd in order to becomea time server if you include "disable ntp" in the ntp.conf configuration file.The one-time clock adjustment functionality of ntpdate and ntp_timeset is notaffected by this bug side-effect.  You can safely use these commands to alteryour system time with reasonable accuracy.The only reference clock that has been tested on MPE is the local clock.  Sobuilding NTP with --disable-all-clocks --enable-LOCAL_CLOCK is stronglyrecommended.NTP makes use of Privileged Mode (PM) capability in order to bind to the NTPnetwork port (123) and to access the low-level clock functions.NTP was ported using the gcc compiler.  Attempting to use the HP C/iX compileris not recommended and has not been tested.Please note that NTP is not an HP product and is NOT supported by HP.  The bestplace for asking MPE-specific questions about NTP is the HP3000-L mailing listat http://raven.utc.edu/Archives/hp3000-l.html or the associated Usenetnewsgroup of comp.sys.hp.mpe.The original author of this port is:Mark BixbyHP CSY MPE Internet & Interoperability Engineermark_bixby@hp.com