[Coco] Timer interrupt frequency (50Hz vs 60 Hz)

[Allen Huffman]

> On Mar 20, 2025, at 4:17 PM, Juan Castro via Coco <coco at maltedmedia.com> wrote:
> 
> The timer interrupt hits 60 timer per second in CoCos made in the Americas
> and a couple of other places, and 50 Hz in Europe and elsewhere. This means
> if I want to count seconds with BASIC's TIMER function, I need to be aware
> which kind of CoCo I have, 50Hz or 60Hz. Is there a way to find out which
> frequency I have by software?

Considering this was one of the questions apps would ask (like Nick Marentes’ games), I think not :(

> I just thought of a horrid solution: count how many times a loop ran
> between two interrupts, and apply some tolerance. Of course, I'd have to
> set CPU frequency to baseline 0.89 MHz beforehand. Get typical values and
> apply some tolerance. Do I really need to do that?

That might indeed be the way to go. It would only take a 1/50th of a second, if you could time it that fast ;-)

		— A