Sorry Galdelico, I didn’t see your question. PS1 games on PS1.
I did, in my research yesterday, find a great auto-patch program, for patching iso’s to disable dithering. The only one I’ve tested so far is Street Fighter EX 2 Plus Alpha, and the results were amazing. The dithering is gone, and it looks exactly as it did in emulation.
I will post some comparative screenshots tonight, but for anybody that wants the auto-patch tool, the download link is here:
Read the readme, it is as simple to use as it can possibly get.