Most of us know the Nintendo NES, some are also known by its Japanese predecessor, the Nintendo Famicom.
On a few differences these consoles are identical.
The only differences are in appearance, additional audio channels which the Famicom has, and the cartridge slot, which counts among Western NES 72 pins and 60 pins on the Famicom.
With a converter you can bridge this gap easily, and almost all Famicom games play on NES and vice versa.
But fewer people are aware of the retro gaming culture in countries where Nintendo was not active, such as behind the Iron Curtain, and in large parts of Asia.
Once the Famicom came out it was already disected by Chinese technicians and copied, these “Famiclones” were initially 1: 1 copies of the original, with exactly the same appearance and almost identical chipset.
These clones were distributed worldwide in countries where Nintendo saw no sales, and took very different forms, and integrated new qualities with original hardware, such as floppy drives, data recorders (whether or not incorporated) RF wireless to TV with antenna, wireless controllers, built arcade stick, multi-cartridge slots for additional SFC, SNES, NES and even Mega Drive compatibility.
Gamers in these countries never heard of Nintendo, and the clone consoles where what they played, therefore “the real thing” as far as they knew.
The Dendy, Pegasus, GRP, Micro Genius etc. were simply the only available consoles, and when the original hardware was later obtained many thought that this was clones of their beloved Dendy, Pegasus, GRP etc.
Many of these clones are not 100% compatible with all games, Castlevania III and Rad Racer II are well-known examples.
However, independent of Nintendo games were also released by software developers who had nothing to do with them.
In many unlicensed games you also find more blood, nudity, violence then you will encounter in official releases.
Although clone consoles are region free, and carts have no region lock, becaus of differences in teh software, some original systems can not run some games.
Many have once had a multi-cart which does not work on their NES or Famicom, but that of the neighbors worked.
Many unlicensed games are “originals”, meaning that there is nothing of the content derived from the work of other developers or franchises, build from the ground up.
There are also unlicensed games where indeed there is piracy, when in fact the used characters or trademarks from other games or franchises, then without permission intellectual property (IP) is used, even though everything is programmed and is accompanied by the code of his own.
A bootleg cart is nothing but a copy of the original game on a cartridge released by a company other than the one who has the rights of the respective game.
Hacks are games where the content is changed, such as backgrounds, title screen, or the characters.
here usually involves games with a copyright, and this is also piracy.
Piracy still produces very funny games.
A backport is based on a game of later or advanced consoles.
Known 8 bit backports for example. World of Warcraft, Plants vs. Zombies, Angry Birds, and Tekken.
Until 2010, there are new games developed for the Famicom / NES, a system that was already nearly 30 years old.
Some of these games look graphically very impressive, partly because the developers after nearly 30 years are more familiar with the technical constraints of the Famicom / NES, and its easier to work around it.