Image on screen scrolls up continuously.

[ClickKlick]

I am trying to make some portable handheld consoles. The first is a playstation one
. I purchased the following display screen http://www.amazon.com/gp/product/B0045IIZKU/ref=oh_details_o03_s00_i00?ie=UTF8&psc=1
When I hook the PSone up to it the Sony boot image looks fine and so does the memory card/ cd select screen. However, when I got to play a game, the video image continually scrolls up or down on the screen. What would cause the image to scroll when running a game, but not when the loading screen or boot selection screen are showing?

Any ideas?

[Bjs]

Scrolling is incompatible game frequency ... if you have a pal console and try to play nstc game then this happens.

Breaker Pro is a swap disc designed to allow one to play import games to allow nstc playback on pal consoles.

And yes it works in reverse, ie, pal on nstc console.

[ClickKlick]

Well supposedly the backup display supports ntsc and pal. However I know it is meant to be hooked up to a camera, not a video game console.

If it is the wrong frequency, is there anyway I can get the screen to stop scrolling? I function generator is too big to put in. But what about a filtering circuit?

[nic2k4]

It's supposed to auto-switch video input format, but I suspect it only does the detection at startup. Verify this by turning off the monitor power while the screen is scrolling, wait 30 seconds, then turn it back on. If you get a good picture, that's what it is. It means your PSone is changing display mode between the menu and the game screen. If there isn't a way to stop that in the console settings you could add a momentary N.O. switch in the power supply to the monitor. If you have a RF modulator, you could try that between the console RF out and the monitor input; the thinking is that video on the RF out should remain at PAL/NTSC rates.

[ClickKlick]

I tried this and it did not change the scrolling screen.

Apply video signal, wait till game is playing, then apply power to the display. Screen still scrolls but when I reset the Playstation one, the Sony screen and boot select screen are steady.

I've tried the YOBO Nes knockoff, the sega genesis, the N64 and the PSone all with the same effect.

[Bjs]

What are the consoles default output signal ... nstc or pal ?

[ClickKlick]

They should be NTSC since I am in the USA.

[ClickKlick]

I just hooked it up to my dvd player and the image on screen is perfect!

What's different about video game signals?

[nic2k4]

The way they display the menu on the screen. I've noticed odd behaviour like that with some VCR's too. If you were to hookup a scope to the composite output, you would probably see that the signal doesn't follow the specs. I wouldn't be surprised if it's related to the pedestal being set to the wrong level.

Try a RF converter between the monitor and console.

[jagabo]

As I understand it some of the old game consoles didn't produce by-the-book NTSC signals. Just something close enough that CRT TVs (which are pretty forgiving) could display it.

[Bjs]

What's different about video game signals?

Gaming consoles carry "sync signal" over the video output which causes scrolling screen issues ... it is not present while no game is being played ... you need to strip it from the consoles video output before it hits the screens input.

Camera's, dvd players ect do not have this issue ...you should have a look at this little project

Build it and your problem should be solved.

[jagabo]

you should have a look at this little project

And this datasheet: http://www.farnell.com/datasheets/78297.pdf

But I don't think that is what he needs. It's for connecting an composite video source to a RGB monitor.