[DSP-10] A Clock Question

[ww2r at mgef.org]

answer: no problems

all my radio computers run in utc for some of the reasons you mention

what i need is a DOS program to automatically set the clock from an nme
gps stream...like nmeatime does in windows. Havent found one yet

dave

ww2r

> Hello All,
>
> I am in the process of "unifying" the clocks used inside the DSP-10
> program
> UHFA.  This is spurred on by wanting to have automatic, precision setting
> of the clock from a GPS.  I have that part more-or-less under control, but
> I am seeing complications in the handling of time zones, and particularly
> daylight time.
>
> First a couple of comments. DOS allows for time zones through the
> environmental variable TZ, which can be read and applied.  The C routines
> use this to automatically change the offset for daylight time, if this is
> specified, i.e., "SET TZ=PST8PDT"
>
> DOS does NOT change the computer time in April and October, it only
> automatically adjusts for it when computing GMT from local time. If you do
> not use the DOS command TIME it will be wrong.  Windows (I don't know
> which
> versions) allows for automatic time change, if Windows is run.
>
> All of this becomes very simple if the TIME command is set to GMT and the
> environment is "SET TZ=GMT0"
> With this, the program never checks for daylight time, and, it turns out,
> all the clock operations can run from a single software time source (the
> source that has the daylight info does not have fractional seconds, and
> visa versa).
>
> Tell me what kind of problems running everything in GMT would create for
> people?  I have always done this, but I know others have used local time
> in
> some way.
>
> Many thanks,
> Bob Larkin  W7PUA
>
> PS- It may not be obvious, but internally to UHFA GMT is a must, as it is
> needed for Moon calculations, Sun calculations, and PUA43 code stirring.
>
>
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