[Coco] OS9 NITROS9 Accurate timer/clock

Gene Heskett gheskett at shentel.net
Wed May 29 13:20:20 EDT 2019

On Wednesday 29 May 2019 09:53:06 am Walter Zambotti wrote:

> I'm looking for a os9 call that can return a better timer resolution
> than 1 second.
There isn't, and the 'tick' could be added to the gettime call I suppose 
but even that would only give 100 millisecond accuracy with the software 
clock.  Some of the other hardware clocks might get better than that, 
but getting into the clock chip to read it would start to take up cpu 
cycles it does not have to spare.

> There doesn't seem to be one!

if you add the ticks to gettime, then you could fine tune it to wake uo 
on the exact tick that starts a second and d0 that to a tick max error.

Thats a technique Jim and I used when we wrote ezcron for the amiga's at 
the tv station, and published it on aminet at the time, as the amigados 
had no cron of any kind. That worked by ending a given seconds work 
calls by getting the current time including ticks and multiplying it by 
the ticks that actually existed between now and the next scheduled 
wakeup, and it then always woke up at a given 1st tick  
of that second. I think I used a similar bit of code in the cron you can 
get from my web site.  You may want to take a look at it.

> Walter
> Sent from my Xperia by Sony smartphone

Cheers, Gene Heskett
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
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