[Real_Character]

Just to keep it short, I am curious about something that someone familiar with SNES architecture might know, but I'm not sure if anyone would know this for certain.

Aside from the difficulty of creating such a thing, let's say there is a SNES homebrew SuperFX2 support. Would that be enough to run in 'higher' definition mode (512x448), with decent speed? Something like a typical SNES RPG, such as Final Fantasy, Dragon Quest, etc. (no 3d effects).

[KingMike]

I have assumed higher definition mode wasn't used much due to slowness caused by more tile updates needed when scrolling, as well as to avoid NES-like scrolling glitches (as if you used the maximum resolution, the entire tilemap would be displayed onscreen with no room to render in off-screen map data gracefully).

Then again, when I think about it, the NES problem might be caused by its attribute table system. The SNES allows per-tile palette selection. I do think the problem with displaying the entire tilemap is the issue (which means to shift a row means having to redraw the entire tilemap and rewrite to VRAM which I think is more data than can be safely written to the PPU in one frame).

[tomaitheous]

Just to keep it short, I am curious about something that someone familiar with SNES architecture might know, but I'm not sure if anyone would know this for certain.

Aside from the difficulty of creating such a thing, let's say there is a SNES homebrew SuperFX2 support. Would that be enough to run in 'higher' definition mode (512x448), with decent speed? Something like a typical SNES RPG, such as Final Fantasy, Dragon Quest, etc. (no 3d effects).

 The first question I have to ask is.. why? For what reason do you need that screen resolution???

I have assumed higher definition mode wasn't used much due to slowness caused by more tile updates needed when scrolling, as well as to avoid NES-like scrolling glitches (as if you used the maximum resolution, the entire tilemap would be displayed onscreen with no room to render in off-screen map data gracefully).

Then again, when I think about it, the NES problem might be caused by its attribute table system. The SNES allows per-tile palette selection. I do think the problem with displaying the entire tilemap is the issue (which means to shift a row means having to redraw the entire tilemap and rewrite to VRAM which I think is more data than can be safely written to the PPU in one frame).

You can clip the display to be slightly less than 512. Hell, one of the Final Fantasy games on the SNES runs with a 240 horizontal resolution (256 clipped to 240 visible pixels). Only the BG layer is going to be double horizontal res and double vertical res, and not the sprites (they'd be only double vert res). But even at that, you're going to "loose" vram space because of the increased storage space for the same screen realestate as low res objects and tiles. Some layering and color transparency abilities are lost in high res mode. I wouldn't say it's necessarily slow or taxing (you don't need an SFX chip or such to use it), just that you loose so much to gain so little.

[Real_Character]

The first question I have to ask is.. why? For what reason do you need that screen resolution???

I'm not sure what you mean by 'need'. Why do we need HD video? Higher resolutions opens up more creative possibilities (assuming the same amount of colors could be used).

But I guess that settles that, if the vram is a bottleneck.

Now that I remember, I have seen one game which apparently uses higher res, in-game (as opposed to just a still menu or logo), but I think it was only the vertical that was doubled. RPM Racing. And it ran choppy.

[tomaitheous]

I'm not sure what you mean by 'need'. Why do we need HD video? Higher resolutions opens up more creative possibilities (assuming the same amount of colors could be used).

 Because you're talking about a system, a retro system, with a specific design scope when it comes to capabilities and limitations. If you want something with less limitations, or more capability, move to dev'ing on a system from a different generation. Unless you need that resolution on the SNES that overrides the limitations that it inherits; thus the question. Is it possible to use that res to make an RPG? Yes. Do the advantages of a higher res out weight the limitations? That's for you to decide. The resolution is pretty much there for brag rights, more than practicality, just like the 64x64 sprite mode of the SNES.

But I guess that settles that, if the vram is a bottleneck.

VRAM is the least of your worries, if you not familiar with SNES homebrew/dev. SNES is not a beginner friendly system to learn to dev on (dev != hack).