Lack of proper high resolution support in openmsx 0.10.1?

Yes, I am agree with this, I will search for another emulator using sdl 1.2 and I will confirm you if this behaviour is due to limitations present in 1.2 version of sdl and, if the issue persists the only solution would be to upgrade openmsx sdl libraries to 2.0 branch.

At https://wiki.libsdl.org/MigrationGuide I read things like this:

"This is nice in that you can change the logical rendering size to achieve various effects, but the primary use is this: instead of trying to make the system work with your rendering size, we can now make your rendering size work with the system. On my 1920x1200 monitor, this app thinks it's talking to a 640x480 resolution now, but SDL is using the GPU to scale it up to use all those pixels. Note that 640x480 and 1920x1200 aren't the same aspect ratio: SDL takes care of that, too, scaling as much as possible and letterboxing the difference"

Please, wait for my next post and i will confirm you if this limitation in SDL is the key for solving this "bug".

Vampier, I said "I hope such issues will be resolved when we move away from SDL 1.2 sometime in the future"

DrWh0 instead of emulators, you can try any other kind of application too. There are many games based on SDL 1.2 (e.g. Sopwith Camel).

OK, thanks for the effort. We're slowly working on things to be able to migrate to a different framework. But it will be a lot of work, so it won't be finished any time soon.

You cannot until we change something with the window size. We still have a 4:3 window (which fits MSX screens), also at full screen, so that gives you black areas at the sides.

It could also stretch the leftmost and rightmost pixel columns to cover the whole screen, but I'm not sure it's a good idea. I think that having black borders emulates a 4:3 TV better.