1200XL to Pal, is it 100% possible?

[Mclaneinc]

 

Hi folks,

 

If I were to get a 1200XL at some distant point in the future, would it be possible to do a full PAL conversion. I HAVE read quite a few old threads on here today and there was talk of CIO and keyboard repeat awkwardness, but as most of the threads are years old I wondered if there's been any progress in a possible full conversion.

 

I doubt there are any kits of what is needed, but a list of what is possibly needed would be appreciated.

 

I'm stuck between doing a PAL convert or just getting a Sophia 2 and running via RGB or HDMI. The issue being that none of my vintage monitors will accept NTSC, be it aerial or composite..

 

All this is just a thought, but input for possible future happenings would be great.

 

Paul..

 

[flashjazzcat]

Repace the master crystal, put a PAL ANTIC in it, and install Sophia 2. Job done. This is by far the easiest (if not the cheapest) way of going about it now, and you get DVI and perfect PAL operation over the legacy video output (which you will want to fix up with ClearPic, BTW) too.

 

[Mclaneinc]

Thanks, Jon, I saw lots of mentions of double to single OS roms and it threw me..

 

Will research clearpic and ask re the crystal when the time comes but that is a long way off..

[Rybags]

Pretty certain the key repeat shouldn't be an issue if the relevant GTIA and Antic are present.  The XL OS (even 1200XL I believe) was written to work universally (though of course you can upset that by running opposing GTIA and Antic)

 

I'm not even sure you'd need to worry about the master crystal if running on a PC type monitor with Sophia - I was surprised how all the ones I tried handled the signal just fine and I doubt they'd care about the difference between e.g. 49.95 and 50.05 Hz refresh.

[flashjazzcat]

6 minutes ago, Rybags said:

I'm not even sure you'd need to worry about the master crystal if running on a PC type monitor with Sophia - I was surprised how all the ones I tried handled the signal just fine and I doubt they'd care about the difference between e.g. 49.95 and 50.05 Hz refresh.

DVI probably won't care, but if you want colour out of the legacy jack, Sophia will only generate the proper PAL colourburst when it senses the correct PAL master clock. So, if the NTSC crystal is left in or even if the PAL crystal is off by a small margin, problems are likely. I saw this recently on a machine here when performing the exact modification under discussion here (the owner sent in some 'iffy' crystals and I couldn't get colour until I pulled one off an 800XL).

[+mytek]

Yes I agree with Jon that the easiest solution would be installing a Sophia 2, PAL Antic, and a PAL master clock crystal. It will not only give you a choice of great looking digital video outputs, but also correct the analog outputs to PAL at the same time.

 

There's also another way to go if all you want to do is convert the original NTSC analog video to PAL. It's a module coming out of the 576NUC+ project called the PALburst board, meant to sit directly under the GTIA chip. Of course you will still need a PAL GTIA as well as a PAL Antic, and the PAL clock crystal. But other then the PAL clock crystal, it's virtually a solder-less upgrade.

 

 

I know MacRorie is very near to selling the 576NUC+ from his TBA website, having place markers and pricing at this time. And since this is a 'separate' piece for that system, perhaps he would also consider selling it independently.

 

[flashjazzcat]

Lenore stopped selling her SMD version of the same device for reasons unknown, but either your or her design going on sale again would be most welcome indeed.

 

Edited June 15, 2021 by flashjazzcat

[+mytek]

1 hour ago, flashjazzcat said:

Lenore stopped selling her SMD version of the same device for reasons unknown, but either your or her design going on sale again would be most welcome indeed.

I never even realized until after the fact that Lenore had made something to do the same thing many years ago.

 

 

Lenore's version was 100% the same as far as the electronic circuit is concerned, but the new PALburst board is much more compact even though it utilizes a lot of THT components instead. Essentially when plugged in with the GTIA piggybacked on top, you hardly even know it's there because the footprint matches the GTIA socket perfectly. The height increase is also very minimal.

[flashjazzcat]

Yeah. Lenore's board could have been a lot smaller (indeed it could easily be confined to the chip footprint), but I was hardly complaining when there was nothing else available.

[+mytek]

Yeah I hear you, and in no way was I inferring that what she created wasn't very useful. But like all things when it comes to technology, stuff can usually be made smaller on subsequent retries.

 

So now lets give a shout out to @MacRorie to see if he might be persuaded to sell the PALburst board separately

[flashjazzcat]

18 minutes ago, mytek said:

Yeah I hear you, and in no way was I inferring that what she created wasn't very useful.

Oh - I didn't get the impression you were inferring any such thing. I just meant that although I thought the routing and footprint could be improved, I wasn't too critical at the time (it's not as if I have ever designed a PCB before, after all).

 

[Gunstar]

I've had my 1200XL converted to 100% PAL with 100% success for quite a few years now. I used Lenore's PAL GTIA board shown above. I converted my 800 to PAL last year by replacing the mobo crystal and buying a PAL CPU board from MyAtari off eBay. Again, works 100%, I've installed an Incognito and Sophia 2 as well now.

Edited June 15, 2021 by Gunstar