I’m working on a home made upscaler similar to the Retrotink 2x, except I want it to display two inputs at once in a split screen configuration. For example, I want to play SNES while a friend plays Genesis at the same time on the same TV.
I’ve been trying to wrap my head around how to do this and realized that the refresh rate of the two inputs won’t be in sync with each other. In order to combine these I need two buffers or something and you end up with a lag of 1-2 frames just to combine them. That’s not including image processing. Assuming my understanding of all this is correct, that is. (it’s probably not).
Anyway, I just want to get an opinion from people on how much lag (in frames) is too much lag. It looks like the Retrotink and OSCC are a frame or less, so what about say 3 frames? Right now I play all my retro games on CRTs so I haven’t got a feel for lag issues on HD screens yet.