OK, the original thread was locked by wd, and the locking has been discussed privately. For the record (stated here because I can't comment on the locking in the locked thread), I don't agree with the reasoning, since the post he quoted also explicitly ended the line of discussion he wasn't comfortable with, and this post (the last one of mine) put the thread well back on track, but the decision has been made. This is where we are now.

Still, I have wd's approval for starting a new thread on the topic, and here it is. We'll keep it civil. I'll refrain from off-topic digressions and hope others will, too. Hopefully the discussion will now properly concentrate on the proposed Normal4x functionality - provided, of course, that the topic still has some steam left.

So, I'll pick up where I left off, replying to gulikoza, and I'll replicate the relevant part of the aforementioned last post here to start off. For the original patch, more context and history, refer to the other thread if necessary.

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integral scaling(...)This gives the sharpest pixels possible (since 4x is used in the horizontal direction and 5x vertical), slight letterboxing and fairly close to real 4:3 AR and no bilinear scaling step.

OK, I'll have to try that with various different LCD's (1280x1024, 1680x1050 with fullresolution=1400x1050, 1900x1200 with fullresolution=1600x1200 - otherwise aspect=false would, if I understood correctly, stretch the image to 16:10 on a widescreen LCD?).

Still, I am of the opinion that 4x (and in the future, 5x, 6x etc.) is beneficial. MAME is the shining example when it comes to scaling compared to any emulator out there, and it accepts -prescale up to 8(!). Like with Normal scalers, there is the bilinear scaling step, but as long as the Nearest Neighbor scaling ends up as near as possible to the target resolution (i.e. the less "distance" the bilinear step has to cover, the better), the slight softening of the image caused by the bilinear step is actually beneficial, depending on taste. To me, that is exactly the case; it makes the image a bit more CRT-like and authentic, and I prefer it over all the other methods. And the resulting AR is precisely 4:3, not merely near it. Large enough NN scaling is extremely important here, or the softening will be too severe.

I'm planning on building a retro PC at some point with a pivoting 24" LCD, and I know that prescale factors well beyond 3 will come into use when running MAME. Bomb Jack, a vertical game, is 224 x 256. Given that a vertically pivoted display is 1200x1900, I can afford to use -prescale 5, making the pre-bilinear resolution 1120x1280. You can imagine how much better the image will look than if I only had 3x scaling (672x768) available 😀. I'm a bit scared at how DOSBox and WinUAE will look, although I've read that the upcoming (now beta) 1.50 version of WinUAE has major improvements scaling-wise.

The DOSBox devs may not see a personal need for more than 3x, especially if you're still running CRTs. But please acknowledge that for a portion of your user base, such a thing is significant. That's all. Thank you.