Pal Vs Ntsc And Framerate Questions

[christo930]

Is it better to run PAL games when possible since they only run at 50 fps? Thats 20% fewwer frames than ntsc. All other things considered, is it best to run pal games?

I also have a question about what the minimum fps should be. In the US we have a tv refresh of 60, but interlaced, which means there is really only 30. When emulating consoles, would you miss anything by doing a frameskip of 1 (which would produce 30fps the same as a tv). Is this the same for PAL? Does PAL run at 50 interlaced frames per second producing 25 or is it 50 full frames per second.

One last thing, I noticed that many games can run with a much slower clock rate than the emulator defaults to. Many older games in MAME for example, can run at much slower cpu clock speeds and it greatly increases battery life. The same can be said for many of the console emulators. I make sure I run the cpu at the lowest possible speed for the game I am playing and it signifcanly improves battery life.

Chris

 

[Exophase]

NTSC accomplishes interlacing by having devices specify a frame as either even or odd, taking 262 or 263 scanlines each at 60Hz, for a perceived resolution of 525 scanlines per 30Hz (note that a lot of these scanlines take place during blanking and aren't actually on the screen, and the amount shown per screen varies per television but most old NTSC consoles have 224, some can do 240)

If the console specifies every frame as even or odd then a true 60Hz non-interlaced mode is achieved. Each scanline only takes up a certain percentage (more than 50%, maybe around 70%, probably depends on the TV) in order to make interlacing work. That's why old consoles tend to have dark gaps visible inbetween the scanlines, and why emulators have "scanline" mode.

Old consoles can be interlaced too (sometimes it's an option in the hardware) but it's still outputting at 60Hz, it's just alternating the lines. If you throw out half the lines you'd still be losing a lot of information. If you average them together you'd probably have something that looks closer to the original.