Re: Wanted: A Very Accurate Timer



Peter Duck wrote:
> In message <1119938446.446717.307410@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>
> Searcher7@xxxxxxxxxxxxx wrote:
>
> > ... I thought that there might be an affordable timer that would somehow
> > keep it's accuracy by via 60Hertz AC. But I guess not.
>
> As has been mentioned repeatedly in this thread, the short-term accuracy
> of power-system frequencies is several (many?) orders of magnitude worse
> than your stated requirement (they 'run slow' at times of high demand,
> but are carefully made to 'catch up' at other times so that domestic
> clocks, etc., don't develop cumulative gross errors).

That's why that won't work...

> Your confidence that the videogame's(!) registers 'will have undergone
> 1,296,000 increments over the course of 6 hours' is certain to be
> similarly misplaced, though if crystal-controlled perhaps only to the
> extent of a few hundred increments.

I'm well aware of the drift.

> This, basically, is IMO why no-one can see the point of your
> accuracy-requirement - you seem to believe that you need it to 'keep in
> step' with a process that is proceeding at rate only approximately-known
> but from which you can't derive any synchronising-information.

No. It is only approximately known, but the "synchronising-information"
will be *visually* assessible from the monitor screen.

Darren Harris
Staten Island, New York.

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