NES Warning

If you would like to use an NES controller on your system, be advised that they're pesky. They want more power than most computers will give them through the parallel port. Although some setups have worked without additional power, it is a common enough problem that you should assume it will happen to you if you try it.

The simple solution is to add more power. Some people have done this by leeching power off other cables in the computer. I prefer to add an additional battery pack with 2 AAs. This has done the trick in every case thus far.