Is the NES and Famicom hardware identical?
From a software standpoint, yes. I know of no way for a game to detect whether it is running on an American system or a Japanese system, unless there are ways to detect the microphone or the absence of the Start and Select buttons on the 2nd controller. Even so, the new-style AV Famicom uses detachable, interchangeable controllers like the NES. From a hardware standpoint, there are some minor differences. The controllers are not detachable on the [older] Famicom, and there is a connector for a third joypad or other input/output device. This connector also serves as the expansion connector [which is found on the bottom of the NES unit). The second control pad has a microphone with volume control built-in, and it also lacks Start and Select buttons. The old Famicom outputs RF only for connection to a TV. The Famicom has no lockout chip, so its cartridge connector is only 60-pin. The cartridge connector also passes audio in and out of the cartridge, to allow for external sound chips to be
