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From: jmaynard@thesis1.med.uth.tmc.edu (Jay Maynard)
Newsgroups: comp.sys.ncr
Subject: Re: My Tower XP clock is slow
Message-ID: <4900@lib.tmc.edu>
Date: 1 Apr 91 03:25:05 GMT
References: <4886@lib.tmc.edu> <1991Mar30.191005.11553@seachg.uucp>
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In article <1991Mar30.191005.11553@seachg.uucp> burke@seachg.UUCP (Michael Burke) writes:
>The Tower XP uses a "soft" clock to keep track of actual time. This "soft"
>clock works ok (generally) as long as it does not miss too many interrupts
>from the "hard" clock. On busy systems, one finds that the clock is a tad
>slow over a couple of days. Your example, while favourable for the
>reliability of the Tower XP, shows how bad the error can become.

My system isn't that busy, but there's another possible cause: at least
on the XP, if you shut the system down, the clock is frozen and picks up
where it left off. Part of my startup routine after a power outage or
shutdown will be to examine the clock, and reset if needed. (Thanks, Steve.)
It may be that the last time I checked the clock was before the last power
outage.

I've been tickled pink about the Tower's reliability. It's run longer than
any continuous run my previous Unix box (a 286 running Microport) ever
thought of. Now if I can just turn 1-meg memory boards (the 256K-chip
variety) into bigger memory boards...

>We once looked providing a "fix" - the Tower XP actually has a TOD clock -
>but we never got around to doing the work.

I would guess this is beyond the ability of us poor souls without a source
license...
Is there a way to read the TOD clock from user-mode software? If so, I could
reuse a trick from the Microport system: let cron fire off a process every
day or so to read the clock and reset the Unix date value.

-- 
Jay Maynard, EMT-P, K5ZC, PP-ASEL | Never ascribe to malice that which can
jmaynard@thesis1.med.uth.tmc.edu  | adequately be explained by stupidity.
  "You can even run GNUemacs under X-windows without paging if you allow
          about 32MB per user." -- Bill Davidsen  "Oink!" -- me