Back in December, I bought a (officially sanctioned!) reproduction cartridge of Tamtex/Irem's excellent Metal Storm NES game. Eager to play it on my Famicom, I had to get my hands on an adaptor. The two brother consoles have a different cartridge port and a slightly different feature set, requiring something inbetween the game and the console to make the connection work. When shopping around, I had my wires crossed entirely, I accidentally bought a NES->FC 60 to 72 pin adaptor, not a FC->NES 72 to 60 pin adaptor, completely the wrong way around, what a plonker.
Oops, anyway! I let the game slumber on my shelf for a while and eventually I bought the correct orientation. Being a cheap bastard, I went for the absolute lowest cost one that fit the bill on the market, lets take a quick look at it;
And here it is alongside it's counterpart.
BOTTOM : If you have a NES and want to play Famicom games.
If you're forgetful (like I am) about which console has which number of pins and which side goes where, the version intended for playing Famicom games on NES consoles has a little itsy bitsy chip on the board, bottom right with a blue mark in this photo. I assume this chip is designed to designed to deal with the NES's infamous 10NES CIC lockout mechanism, while the version intended for Famicom consoles (which had no such lockout device) are entirely passive with no circuitry or much of anything on the board besides the traces and the cartridge port.
The soldering quality is far better than in the preview image, and curiously, the PCB has ©1998 Nintendo on the board, a hilariously illegitimate claim. This badge wasn't on the page image when I bought it, so it may be an on-again off-again kinda deal or depending entirely what factory it was sourced from. Many of these Alibaba Chinese produced doohickeys have a common PCB layout with little tweaks and adjustments depending on who ordered it, when they ordered it and what factory it was made in, so details and markings do fluctuate.
Connected to that aforementioned Metal Storm cartridge and stacked on my Famicom, it looks like this.
A strong gust of wind or a gentle knock is more than enough to disconnect the cartridge and crash the game. Normally when a Famicom cartridge sits in the slot it is held tight enough to prevent it from wobbling, you can actually lift a console up entirely via the inserted cartridge and it will still work (please don't do this - but you can). This thing sits extremely loosely in the slot and it lifts out with absolutely zero resistance!
Unfortunately, the ability to easily remove the adaptor from the console is not mirrored on the game side of the equation. This is my biggest grievance against this product, that the grip force on the cartridge is monstrously high, I fear for the safety of a cartridge plugged in using this contraption, you can feel and hear it scraping against the contacts, not good!
I assume this will loosen up with some usage, but in the meantime I will avoid using it on legitimate cartridges and stick to reproductions like this one, I fear there's a real risk of damage here!
The cartridge faces label rearwards in the slot because the Famicom and NES have an inverted cartridge connector, not just a different pinout. Some other, fancier, adaptors have visible traces running in and out of the board to correct the orientation, but this style wasn't (cheaply) available at the time I ordered this, you can see it clearly on this board here;
Back to the device, once you get over the stability and grip issues from it's wonky design, it works exactly as you'd hope, American NTSC games work flawlessly! If you're in a 60hz region, this is great! But being a completely passive adaptor, this does absolutely nothing to ensure UK/European PAL NES cartridges work correctly. As a UK native, this prohibits me from playing games picked up from my local game shop, but this isn't the fault of the adaptor. The 60hz NES and Japanese Famicom are more similar to each other than the 60hz NES and 50hz NES consoles, which while looking very similar externally, use different components running at different speeds and are adapted to different TV standards.
Some PAL released games will not work, others will run at the wrong speed, others will run at the correct speed (finally), some will somewhat work but have bizarre issues and graphical bugs. Not even the fanciest of flashcarts can account for this difference, playing such games cross-region is a compatibility minefield, and this is nothing to do with the adaptor. The only way to fix this for sure is to modify the console itself to run 50hz software. I'm not doing that, but you may want to if you're itching to play a legitimate PAL copy of Gimmick or Elite, for example.
On a lesser note, but still a little concerning is these anomalous tabs that stick out from the device. They serve the dual purpose of giving you something to grab onto when removing a cartridge from the top of the adaptor, and when inserted they rest on the upper body of the Famicom so all the weight of the cartridge isn't going directly into the cartridge port. Not a bad idea, but they're so wide and ungainly they rub against the back of docked controllers on an original style Famicom! It likely won't cause anything worse than light scuff damage, and won't affect you if you're using it with a later AV Famicom model, but it's another mark against these. I've personally snipped mine down since taking this photo.
Overall? Not great! Even giving it the benefit of the doubt and assuming the problems I had with mine are manufacturing aberrations that may or not be fixed, this thing is ghoulish and untrustworthy. I'm personally cool with bare PCB products, but I don't think that makes sense here and will upgrade to one that's enclosed in a proper shell at some point.