> If you have your screen set to 60 Hz and play "Vs. Super Mario Bros." (which is also > set to 60 Hz) and Mario stands on the ground and you press the jump button, then it > will take 3 frames until he jumps. So, from pressing the button to the first jumping > animation on the screen it's 3 frames. That's our basis. And now we see how many > frames the whole procedure needs with additional options.
As another data point, I tested using a 60 fps camera on my Macbook Pro Retina with SDLmame 0.148. I couldn't use Vs. Super Mario Bros because apparently my ROM set is too old for that game. However, using Donkey Kong and 1943, I found that the time from the caps lock LED coming on to the first apparent on-screen action (first jump sequence frame, or first fired shot frame) was consistently 3 frames.
I also tried my desktop Linux system with an integrated AMD graphics card (on the motherboard) and SDLmame, can't remember what version, but a few versions old at least, and the delay was a consistent 7 frames.
I do wonder what the 'minimum' achievable delay is, I suspect it's not possible to do better than 3 frames; and I also wonder what the delay would be with the real hardware. It's quite possible that the game itself only samples inputs every 3 frames, or samples every frame but doesn't apply the action immediately for whatever reason.
|