Aspect Ratio for Genesis games on PS2

I’m using Free McBoot 1.953, and I’m having issues with the aspect ratio on Genesis games – I’m trying to get everything set to 4:3, but it’s not working.

I downloaded the latest cores, and the only one that works for me is PicroDrive. Upon booting, the menu screens in games look great – 4:3. But when going into actual gameplay, the sides of the screen get cut off, or, in some cases, it looks skinny.

I’ve tried everything from different aspect ratios, to changing settings like ‘Core Provided’, ‘Par’, and turning ‘Crop Overscan’ on and off… nothing. The screen is still cropped.

Other emulators, such FCE Ultra (for NES) and SNES Station work great – no issues at all. So I’m thinking that it needs to be something within PicoDrive itself – unless there is a setting elsewhere that I can change (FreeMcBoot’s Configuration, GMS?) which won’t affect my other emulators.

Thanks for any help! I’m at a loss.

I think this may be a limitation of the PS2’s output resolution. That is, I think it’s always outputting a single, low resolution (720x480i, maybe?) and whether the image fits or not has to do with how the native res divides into the available res.


I think you’re right, and it depends on the game.

For example, Sonic looks perfect. But with games like Super Monaco GP and NHL 95, the screen squishes.

I’d love to know if anyone has played those two games in particular with any success.

It looks like both of those games use 256-width mode for the main gameplay:

Wow thanks, I never knew about that.

Is there anything I can to do fix it?

So, it seems like the PS2 is putting out 640-px width, so 320-width fits in just fine, but there’s not a lot of pixels to work with to average out the unevenness caused by fractional scaling. This is why the PS1 Mega Man X collection games have borders on the sides.

Bilinear filtering can help with some of that at the cost of sharpness, but you’ll have to figure out a way to get the image to stretch, and I’m afraid the PS2 may not be able to do that (a lot of older fixed-function graphics pipelines don’t have any straightforward way to do it).

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I’m able to get the image to stretch to the proper 4:3 if I set my TV to widescreen (at the cost of having non-gameplay sections wider than intended, but that’s fine).

In terms of sharpness, I’ll probably switch over to PGen, since games look a lot better for me with that emulator. It also has the aspect ratio issue, but I think that’s the best I can do when using the PS2.

Thanks for your help, I learned a lot!

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I believe the PS2 can output all PS1 modes, at least 512px res is also used by native PS2 games, so this is really a limitation of the homebrew. The commercial retro collections were often shoddy, may also have something to do with the development tools of Sony.