Hello,
When reading the 6502 primer (clock generation topic), I had few generic doubts. Can anyone please clarify them?
1. In the primer, there is a mention about series and parallel resonant crystal. How do we identify one? is there any marking on the crystal? or it is just the connection we make to them?
2. In the market, I found two types of through hole crystals (Shape)
https://robu.in/wp-content/uploads/2019 ... ator-2.jpg
https://robu.in/wp-content/uploads/2019 ... 863346.jpg
is there any difference between the two?
3. For dividing the oscillator frequency, is a counter IC reliable? like a decade counter?

Thanks,

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

Hi Garth,

Thanks for your replies.

I "assumed" the same when reading through the primer.
But when I was reading some article online, from a company called ECS, I got this doubt.
They say this in that article :

Here is the link to the article :
https://ecsxtal.com/choosing-series-or- ... pacitance/
I was confused when I read this. Does they mean that, all crystals are made same and based on the application, they differ?(parallel and series)

Thanks.

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

Thanks for your inputs.
And interesting. I came to know that there exist ovens for crystals!

I'm reassured that Garth's clock generation page does mention all-in-one oscillators, aka clock cans. I think it's worth saying that these days most people would prefer those: they produce a clock, and you don't need to worry about making them oscillate. It's relatively common to divide by 2, to get a precisely even mark-space ration. Here's what Garth says


(I quote it and mention it here because it's not front-and-centre and I think could easily be missed.)

Hi BigEd,

Thanks. Yes. I read that indeed. I also have one such oscillator (1Mhz) in my 6502 prototype.
Since I am from a microcontroller background (where we just plug the crystal and two load capacitors to the XTAL pins), I was just curious about the oscillator circuits and their types. When we purchase the cystals, they just give randomly the big one or the small one. Honestly, I never knew the difference and why they are shaped like that until today!.

On a side note : Garth mentions that the oscillators cost almost same as crystals (double? triple? the cost)? But where I live in India, it is not the case, we can easily get crystals for 0.1 to 0.2 USD. But the can oscillators has a minimum cost of around 5 USD and they are not easily available in Radio shops. You have to go to digikey or mouser.

Ah, an interesting difference in local conditions!