Emulation FAQ


Jnes User Manual
Emulation FAQ

  • A game doesn't work as it should, what should I do ?
    If a rom doesn't work correctly, the first step is to verify you have a rom that is valid, download a ROM verification utility from the Internet, these tools can save you countless hours of work. If you encounter invalid rom images, try alternate sources. However, if you would like to fix the rom yourself, download a NES Header editor, the most common problems are:
    • The rom header contains invalid mapper number, mirroring or 4-window information
    • The rom was over-dumped, these are rather hard to fix if you aren't familiar with the NES format
    • it's possible you downloaded a bad dump that is unfixable
    • The game just doesn't work with Jnes, you are encouraged to try out other emulators.
  • What's that black 8 pixel wide line going down the left of the screen ?
    The NES has a "clipping" feature that clips the left 8 pixels on each scanline, if it bothers you turn it off. However you should be aware if you turn it off visual artifacts within those 8 pixels may show up, because they weren't meant to be displayed.
  • I am having problems with game genie support, I obtained a code for a game and when I use it there are some problems with the game or the code doesn't work. What can I do ?
    Some game genie codes are made by hackers and may not be done properly, use them at your own risk. Sometimes as seen they cause really strange behavior, I can't fix that.. Also people come across codes sometimes that simply do not work, the biggest problem here to get some of the codes to work is to reset the game after entering the code, some codes do not work when you enter them as the game is playing, just like on a real nes you can't do that, makes sense.
  • Any plans for FDS, or mappers that aren't supported?
    Nope, none at this time or in the future.
  • Does Jnes support PAL roms?
    Jnes has an option that allows you to either automatically detect the region or set it manually. The emulation is changed depending on region for things like CPU speed and frame rate, so generally, PAL games should work.