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Conference wrksys::alphastation

Title:Alpha Workstation Conference
Notice:See note 1.* for conference notices
Moderator:WRKSYS::HOUSE
Created:Wed Sep 07 1994
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:1996
Total number of notes:9122

1991.0. "Please Help :au433 Alphastation" by ZPOVC::SOONHENG () Tue Jun 03 1997 21:35

    Hi all,
    
    I have a customer who wants to know the accuracy of RTC(real Time
    clock) for the 433au Alpha Workstation.
    
    Would appreciate if anyone could tell me the pointers to such info
    or any relevant person I could contact in Engineering to get further
    details.
    
    Thank you.
    Soon Heng
T.RTitleUserPersonal
Name		DateLines
1991.1same as a quartz wristwatchWRKSYS::SCHUMANNTue Jun 03 1997 21:447
It's typically about +/- 1 min per month. We don't test it or guarantee
a specific limit. Also note that OS sometimes will lose ticks because of driver
bugs (too long at high IPL, etc.) and this can further degrade accuracy. For
accurate long-term timekeeping, you should use an internet time reference or
cesium clock, etc.

--RS
1991.2Many Previous Discussions...XDELTA::HOFFMANSteve, OpenVMS EngineeringWed Jun 04 1997 11:0916
   This question has been asked (and answered) a number of times before.

   See note 530.2 in WRKSYS::MIKASA, and VAXAXP::NOTES$ARCHIVE:ALPHANOTES_V2
   notes 48.* and 730.*, and particularly 48.6, for the BB_WATCH (TOY) clock.

   The interval clock drift is specified as 50 ppm or better, for the OpenVMS
   PALcode.  See ALPHANOTES_V2 notes 172.*, TURRIS::DIGITAL_UNIX 185.*, etc.
   I suspect this will be the minimum for NT and UNIX as well, and that the
   actual drift will be less than this.

   Be aware that the tick size calculation can vary.  See ALPHANOTES_V1, note
   564.8, among others.

   There are other discussions.  See http://altavista.notes.lkg.dec.com:8000/.
1991.3ZPOVC::SOONHENGWed Jun 04 1997 21:185
    Thanks for the information.
    
    Regards,
    Soon Heng