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ramapcsx2 / gbs-control

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Dropouts and garbage on screen during resolution changes #332

Closed JaCkBoston closed 2 years ago

JaCkBoston commented 2 years ago

The setup: a PS2 Slim 90004, with a component cable running into the GBS, then through a lag-less VGA-HDMI adapter into the display.

The issue: When changing from interlaced to progressive scan modes the picture fills with garbage for a second, loses sync, blackouts for another, and then comes back to normal. The same happens between NTSC/PAL output changes.

How to replicate: Switch resolution on the fly while the GBS is running.

The issue can be seen in my video here: https://youtu.be/7csHB8WxTgk

This doesn't seem to happen in other people's setups and most people show the GBS to switch resolutions almost instantly and effortlessly.

I must add that this doesn't seem to happen with SCART cable when changing from PAL to NTSC and back, but I can't check 480p as it doesn't work due to sync-on-green not being supported, I guess.

Is this an issue with the GBS itself or the cables/PS2?

Finally, here's a picture of my unit(currently without enclosure as I wait for the model to get printed). Could the longer cable to the external clock generator cause something like this? I don't experience any sync problems apart from this.

photo_2022-05-24_14-51-57

ramapcsx2 commented 2 years ago

Those are pretty normal for these kind of switches (between standard res and the "HD" modes).

JaCkBoston commented 2 years ago

Those are pretty normal for these kind of switches (between standard res and the "HD" modes).

Hello rama, so it's nothing out of the ordinary, and changing caps for sync-on-green as you suggested in this issue (https://github.com/ramapcsx2/gbs-control/issues/219) won't mitigate this behaviour?

ramapcsx2 commented 2 years ago

Internally, the jump from ~240 active lines to ~480 (or more) is a big change. It causes a full reconfiguration of the chip, which is what causes the garbage and also a lot of sync issues. I tried a few tricks to mask this as best as possible, so what you get is already the improved version :p

Better parts (caps) won't be able to fix this, as the problem is that full reconfiguration, which is definitely necessary.

ramapcsx2 commented 2 years ago

In fact, only a few select resolution changes are able to do with just minor reconfigs: Interlaced to progressive (480i to 240p) or the other way around, for example.

JaCkBoston commented 2 years ago

I see, thanks for the clarification, Robert. I'm closing this since it's a non issue :)