Need Crystal for a PAL Conversion, But I'm in the U.S.

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DistantStar001
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What do I need for a NTSC to PAL conversion on a short board?

Post by DistantStar001 »

So like the title says, I have an NTSC VIC-20 sort board and would like to convert it to PAL since I live in the U.S. and PAL VIC-20s are hard to come by over here. Also, 6561 VICs are far easier to find than 6560s just about any where.

In any case, I have a short board missing its ROMs, CPU, VIC, and VIAs. I've already sourced replacements for the CPU, VIC (I have two spare tested 6561s), VIAs and Character ROM. Still working on the BASIC and Kernal (I know I need the PAL specific Kernal). I also know the crystal needs replacing. But it's the Passives that are the issue. The only sight that describes the process showed a picture of the parts but not the values of the ceramic capacitors. So if anyone knows the full parts list that I need for this conversion it would be appreciated.
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Mike
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Re: What do I need for a NTSC to PAL conversion on a short board?

Post by Mike »

You might want to take a look at this thread: VIC20 NTSC > PAL Conversion.

The OP links to a document on zimmers.net: PAL VIC20 Goes NTSC (just backwards).
DistantStar001
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Need Crystal for a PAL Conversion, But I'm in the U.S.

Post by DistantStar001 »

Just as the title says. I have all the passive components, the 6561 VIC, the -07 Kernal ROM... all the bits are good to go, except the 4.43618MHz crystal. It's just not a common frequency where I live, and I couldn't find it on Mouser or Digikey either. Any ideas?

(mod: thread merged with already existing NTSC->PAL conversion thread of yours)
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srowe
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Re: Need Crystal for a PAL Conversion, But I'm in the U.S.

Post by srowe »

I can find 4.433MHz crystals here in the UK quite cheap, no idea if that's close enough.

Edit: the only exact match I can find are in France

https://www.ebay.co.uk/itm/324091049707
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Mike
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Re: Need Crystal for a PAL Conversion, But I'm in the U.S.

Post by Mike »

The PAL colour carrier frequency is 4.43361875 MHz, BTW. Note the extra 3.

These quartzes are easily found on mouser.com or other distributors.
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JonBrawn
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Re: Need Crystal for a PAL Conversion, But I'm in the U.S.

Post by JonBrawn »

https://www.mouser.com/ProductDetail/AB ... amrg%3D%3D

I recall that there is an extra capacitor required to get the crystal to start oscillating at the correct harmonic, so keep an eye open for that.
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mythic66
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Re: Need Crystal for a PAL Conversion, But I'm in the U.S.

Post by mythic66 »

This is the cap that Jon is talking about. You must install it.
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DistantStar001
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Re: Need Crystal for a PAL Conversion, But I'm in the U.S.

Post by DistantStar001 »

Mike wrote: Sat Jul 06, 2024 4:33 am The PAL colour carrier frequency is 4.43361875 MHz, BTW. Note the extra 3.

These quartzes are easily found on mouser.com or other distributors.
Thanks! I had been going with the parts listed on this website: http://blog.tynemouthsoftware.co.uk/201 ... rsion.html

Having the correct frequency makes things a lot easier!
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