We suspect that many that own a Nintendo Entertainment System: NES Classic Edition (Nintendo Classic Mini: Nintendo Entertainment System in Europe) will have fallen in love with it, but it has some flaws. One of these is the incredibly short controller cable; putting aside the retro 'realism' of wired controllers in this day and age (a weird argument for a tiny box running ROMs), the cables on the accompanying controllers are about as short as is feasible. Ultimately you'll need to be sitting very close to the little system to play it.
A post on Reddit has tried to break down why the cable is so short, and has focused on the controller being - in essence - a Classic Controller that can be plugged into Wii Remotes, as seen by the port it uses. The post by 'emuboy85' focuses on the cable and technology in the Nunchuk, primarily how it communicates signals such as button presses and control inputs. It's the 'communication protocol' used, the theory goes, that means cables for the Nunchuk and Classic Controllers need to be short (especially when keeping costs low).
The communication protocol used is I2C , this protocol was designed in 1982 by Phillips (now NXP) and was designed for "high speed" chip to chip communication, it does have some limit for the actual standards , first is the speed, second is the length, according to this the length of the NES mini/Nunchuck is right 50pF , which is the maximum you can get from a yet-flexible cable.
So, why they didn't make a thicker cable? Because would have been more expensive and less practical.
And what about the extension cables? The probably works but are pushing the limit of the protocol, you probably get some communication errors but you don't notice them while you are playing.
Why Nintendo didn't use another communication protocol? Because otherwise they would had to make a new set of controllers just for the mini, not compatible with the wii and wii u which is an expensive procedure, design and manufacture the connector itself is really expensive and the NES mini is a small product for Nintendo.
It seems feasible, though the NES Mini controller could have had a longer cable. We compared our NES Mini pad with a Nunchuk and a Super NES Classic Controller (an old Club Nintendo reward) - both the older controllers have a slightly longer cable. So even if this theory is 100% correct, which it may be, the NES Mini controller could have still had a little more length in the cable.
It's an interesting theory, in any case. Let us know what you think in the comments.
With thanks to Benson for the heads up.