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Annotation of embedaddon/ntp/html/hints/mpeix, revision 1.1

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