I always thought 1 fps meant 1 frame per second
Sure it is one frame per second... but is it a pc frame or a psx one?
Well, a while ago _Demo_ suggested to do it in the psx way (the psx is doing 50/60 screen updates in the second... not every frame is painting something new, though)... and we plugin coders did it
The new fps measuring has certain advantages, so it's much easier for the plugin to get the right mdec speed (with fps limitation enabled), and of course it's much easier for the user to see, if his system is reaching the 'right' psx speed - for PAL games now you have to reach always 50 psx FPS... in the old PC fps way (which only measured real bufferswaps on your gfx card) it was sometimes 25 PC fps, sometimes 50 PC fps, sometimes even something more weird like 42,736 (<- just an example, not calculated

)... much harder to say, if the game speed was 'right'.
Only very few games don't like the new psx fps limitation (like Winning Eleven), so you can still switch back in Lewpy's and my plugins to the old pc way.