Hi, I just got a PC and was wondering if anyone knew the emulator Niftski uses for his runs or any other popular emulator for super mario bros. I've been looking for about an hour and can't find any good emulators that I know are safe. Thnx!

I just got an emulator that can play SMB1 roms but whenever I enter FCEUX it shows the screen not fit with my computer screen. Whenever I try to enter full-screen, the picture is too large and I can only see a corner of the game. I've been trying for hours now so if anyone has any suggestions I would love to hear them! Thanks!