MiSTer FPGA Forum

Posted: **Mon May 16, 2022 5:44 pm**

It does not look like the PSX has scanlines available just yet. But is it even possible with the option of wide screen?

Posted: **Mon May 16, 2022 5:58 pm**

Yes they are. PSX core fully implements the official framework. In fact, the framework had to be closely tailored during the development of the core, so the two would be perfectly compatible.

Mind you, as the BIOS screen (and many games) are 480i, you may not get what you're usually expecting from 'scanlines', so tweak your settings accordingly.

Posted: **Mon May 16, 2022 6:56 pm**

The scanline filters aren't visible until you get to a 3x scale. If you are viewing 480i stuff in weave mode, that means you need to be at least 1440p.

You can also use shadow masks to create scanlines, like the monochrone/Aperture Grille. However for 1080p you basically have to be using fixed vblank and 216 crop for the scanlines to line up appropriately. And of course actual interlacing does not display static scanlines but we don't have much of a fix for that right now.

Posted: **Thu Dec 22, 2022 8:39 pm**

Why can't we have scanlines at 2x scale? I tried shadowmask instead (2x rotated Sony PVM), which works but doesn't seem to be integer aligned so doesn't look quite right. I'm trying on some 480i PSX games (Tekken 3, Ridge Racer Turbo).

Posted: **Fri Dec 23, 2022 1:57 pm**

RowanDDX wrote: ↑Thu Dec 22, 2022 8:39 pm
Why can't we have scanlines at 2x scale? I tried shadowmask instead (2x rotated Sony PVM), which works but doesn't seem to be integer aligned so doesn't look quite right. I'm trying on some 480i PSX games (Tekken 3, Ridge Racer Turbo).

I think because 480p resolution scanlines are intended to be used with the scandoubler and the PSX core doesn't use that part of the framework.

Scanlines on 480p at full screen will have a lot of shimmering and issues because the original PSX system is not a stable 240 resolution, every game can just assert whatever resolution they want within the limits of the system.

Posted: **Wed Dec 28, 2022 2:37 pm**

No Rowan is running into a different issue. Sometime between when I last posted in this thread half a year ago, interlacing was changed so that it uses the horizontal filter in place of the vertical one, which is typically going to be some kind of interpolation. This was a cheap fix so that scanlines did not appear on interlaced content, because yeah you would not see stable and fixed scanlines using 480i on an actual CRT.

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Are Scanlines Possible for PSX Core?

Are Scanlines Possible for PSX Core?

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Re: Are Scanlines Possible for PSX Core?

Re: Are Scanlines Possible for PSX Core?

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Re: Are Scanlines Possible for PSX Core?