Getting Crystals Made

[Chuckt]

I heard that it wasn't too expensive to get crystals made.

www.quartslab.com/
http://www.icmfg.com/

[brad]

I heard that it wasn't too expensive to get crystals made.

www.quartslab.com/
http://www.icmfg.com/

Thats quite interesting. Im just wondering what application I would need a crystal made to an exact specification. I guess some sort of radio circuit where you need the frequency to be locked to a dead set frequency?

[Chuckt]

I'm thinking about running a 65C02 or 65C816S processor at faster speeds than 1 or 2 MHZ like 14 MHZ and I think the crystal is used for running the clock. It also has something to do with generating a signal for NTSC or PAL video which is now replaced by our current standard which is ATSC and some people just stick with VGA. Some people use digital PLLs to generate clock speed but they are beyond other people's understanding to explain it so I would have to learn it myself.

I suppose if you want to overclock some of these microcontrollers, a crystal would be needed but things can get involved including random misbehavior of chips through exceeding the CPU timings. I'm told that it isn't worth having a crystal made until I learn to run a processor at regular speeds.

[Garth]

I've used Jan Crystals too. They used to have (and hopefully still do-- their website is being re-done ATM) an inexpensive service for custom frequencies which I helped myself to when I was active in amateur radio. For processors though, the off-the-shelf frequencies probably are plenty good.

To see how fast I could get a home-made computer to run before it started having problems, I have made a couple of variable-frequency oscillators, and turned the trimmer until problems showed up, measure the frequency, and reduce that number a bit to get some safety margin before committing to a crystal or crystal oscillator. Diagrams and more explanation are at http://forum.6502.org/viewtopic.php?f=1 ... 478#p17478 and http://forum.6502.org/viewtopic.php?t=1576 .