But if it was recommended, chances are good that it was because they are common. If there's no need for a specific frequency (because the crystal isn't being used to supply something else that does need it) one might as well go with a cheap crystal in the general range desired.
Michael
Gee, Brian, I've known this since the mid '60s. I have a few oddball color burst crystals, including an early Zenith one in a glass envelope like a miniature TV tube. I am disabled, but I have worked as a broadcast engineer at three TV stations. I guess you didn't see the winking smiley?
-- ? Michael A. Terrell Central Florida
Hi Brian, Everyone else answered your question for me! As they said, NTSC colorburst crystals are very common and very cheap. The firmware in the micro doesn't need a higher clock frequency than that, so that's why I chose it. The micro internally divides the 3.58MHz by 8950 (179 x 50) to produce a 400Hz reference for all its timing. It worked out pretty well. :)
Regards, Bob
"Brian Goldsmith" wrote:
Oooops, I was replying to Michael not Brian! :)
Bob
Bob Parker wrote:
How are you doing these days, Bob?
-- ? Michael A. Terrell Central Florida
Hi Michael, I'm pretty busy now. I've done what I told everyone I'd never do again = working for someone else, designing circuitry for engine control computers (or trying to). How's things down in 'gator-filled Florida these days? Maybe we should continue this by e-mail...? :)
Regards, Bob
"Michael A. Terrell" wrote:
Ahhh go and visit him Bob. If you still have all that hardware in your leg the gators 'll only break their teeth
David
Bob Parker wrote:
G'day David, You sure do pop up at the least expected times! (1) Florida's further from Sydney than you might realize. (2) There are only 2 screws in my leg now, so I wouldn't trust that to protect me from 'gators. Do you realize that believe it or not, it's
30 years ago in just over a month from now, that they put all that stuff in my leg? Where does the time go???Bob
quietguy wrote:
You would be surprised what a gator can bite through. I've seen cars on the Orlando TV stations where a gator bit a chunk out of a car or pickup truck. One man left his tailgate down on his truck and had a gator in the truck bed the next morning. he had to wait for the state to send a licensed trapper to remove it and take it to the Everglades to release it.
Not many gators in Marion County, but there were plenty about 30 miles south of here at my old house in Lake County. It was a common sight to to see a gator run across the yard heading to or from the marsh behind my workshop.
I'd like to meet Bob. I think he's almost as crazy as me! ;)
-- ? Michael A. Terrell Central Florida
He's a great bloke to work with - good tech and laugh a minute. But if the bugger ever offers you a cup of coffee be sure to check the inside of the mug handle - you never know what you might find there
David
"Michael A. Terrell" wrote:
No problem! I don't drink coffee. I've talked to him by e-mail for several years and I think he's an OK guy.
Maybe I should send him a small gator to fatten up for Phil?
-- ? Michael A. Terrell Central Florida
Hey, fair go. We have animal cruelty laws here you know :-)
David
"Michael A. Terrell" wrote:
Now David, you know that I would *never* stoop so low as to play practical jokes on anyone!! Thanks for telling nice lies about me, though.
Bob
quietguy wrote:
How about "Impractical jokes"? ;)
-- ? Michael A. Terrell Central Florida
It wouldn't work anyway. The gator would get one taste and spit him out.
-- ? Michael A. Terrell Central Florida
Hey Bob, send me a $1.33 in used notes and I'll keep quiet
David
Bob Parker wrote:
OK, I'll do that! Or maybe I could tell them about the time you got someone to hang onto the exposed ends of the wires coming out of a plug you inserted into the 240V power outlet, and were about to throw the switch....? Now that is something I'll never ever forget!
Bob
The look on your face as I hit the power switch was priceless - and when the apprentice (who was holding those leads) hit the floor I thought you were going to freak out!
David
Bob Parker wrote:
Ahhh, now you understand the motivation for some person (not further described) sabotaging your coffee mug!!
Bob
quietguy wrote:
So what frequency was it after all? Mark
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