Switching crystals on a PSOne screen

[Kyo]

Ok, so the NTSC psone screen has a 3.579545 crystal, and the pal ones has a 4.433619 crystal. I'm thinking about trying to see what happens when I replace my PAL crystal with an NTSC one and give it an NTSC signal. My supplier happens to carry both these crystals (must be some kind of standard) so I figure maybe it'll be able to play ntsc, it's a reasonable assumption. Sort of. Maybe it'll be PAL60, that'd make more sense.

Any objections to this? I won't be able to do it until I have enough stuff I need together to justify placing another order (just placed one unfortunately - there's always something you end up needing afterwards. Ergh).

But some of you may now be asking "Kyo, why?"
Well the answer to that is somewhat simple;
1) If it takes NTSC (as opposed to just pal60) then that'd be an easier way for me to get NTSC screens without paying 40$ shipping
2) I could make a switch between two oscillators on a console that is modded to output both (like the SNES can be modded to go to 60Hz, the newer one to output ntsc - which is good for game compatibility and removing the "pal bars")
3) Why the hell not? I ain't got nuffin' better to do.

[Erlex]

I don't see why not. Unless there is something else that differentiates a PAL screen from a NTSC screen that would make them incompatible with each others signals. Look up some specs on those chips, I recall someone a while ago saying that a data sheet had some kind of information on the exact thing you are talking about.

[zenloc]

It won't work... The crystal is only for the refresh rate. The colour differences will not change. So it might work but you'll get a black and white image. There is another component which I believe you could switch which will give you colour but I'm not sure.

My findings:

On a NTSC screen I connected a pal composite signal. I get scrolling picture (50hz issue) en black and white screen. I then select 60hz in the game (double dash supports pal60) then scrolling stops but image is still black and white. BUT when I connect pal RGB the image is in colour I then switch game to pal 60 and voila!! perfect pal rgb on a ntsc psone screen. So a NTSC screen works with pal60 in rgb mode. So my conclusion is that the rgb lines / csync are the same for both regions but only the refresh rate is different. Composite works differently sadly and you will have to switch more components to get it to work.

I have yet to try a ntsc signal on a PAL screen. I'll be getting a ntsc console very soon so I can test it.

So switching the crystals would only solve the refresh rate issue. Not even sure if it will work but you can always try. It won't damage anything.

I'd be more than willing to help you out anyway I can. I also have been looking to make a ntsc/pal compostible psone screen.

[Kyo]

Well, I have a PAL Psone and an NTSC PSOne, and screens of both regions. I do realize that composite would give me a black and white image, but from what I found when I switched my screens (which run on RGB in the psone as well all know), they both support a colour picture. Of course you're absolutely right in that it will only work with RGB, zenloc but that's all I was going for anyway. Most consoles support RGB (sure, the N64 doesn't, but I don't know of any regionmods for that anyway. I'll admit I haven't researched it much, though)

I guess we have different definitions of "won't work"
Thanks for your input! This reassures me!

[vskid]

Skyone was once trying to reprogram the PSone screen. Maybe he knows how to make a PAL screen think it's NTSC (after switching crystals).
http://forums.benheck.com/viewtopic.php?f=8&t=24451" onclick="window.open(this.href);return false;

[zenloc]

sorry I take it back.... I don't mean it won't work period it just might only work for RGB (Since that's all your going for). I was talking about composite and rgb. Making it fully pal/ntsc compatible on all video inputs. That would not be possible with just a crystal switch.

Although I'm not quite sure about just a crystal switch. I was reading the datasheets soms of the chip a while back and I remember there were also other components but I'm not sure.

Let us know if the switch works!!!! I'm really interested to see if it works Might even be possible to make an automatic crystal switcher which detects the input and switches it accordingly

[Kyo]

Well I was going for a double throw switch that would switch the crystal and the console mode simultaneously. I'll definitely keep y'all updated