NES Programming

The NES included rudimentary cartridge validation, meaning that only licensed games would work on it. NES emulators, however, don't bother with the validation, and there are other ways around it on hardware. Short answer: No.

By cartridge validation, do you mean the 10NES chip? To my understanding, all a cartridge needed was a 10NES chip on it to be able to run on the NES. There are tutorials on how to install a flashable PRG-ROM and CHR-ROM so you can run your games on a real NES. Here is one: http://www.raphnet.net/electronique/nes_cart/nes_cart_en.php. You need a real licenced nes cartridge however, so selling games might not work so well.

Yes, that's what I was referring to.