I overread the “adapter”. Why is that there? You are right, it can be easily mistaken.
Didn’t know about the NES. I actually own one, but it is on my parent’s attic since I realiced it looks like crap. Always thought the connection port is the same. But still it’s true for SNES, N64 and Gamececube (PAL+NTSC). Never tried my NES on the OSSC thought.