Gyromite NES Import Adapter Guide

Presented by CRTGAMER, Ziggy587 & Ack

This article is based upon CRTGAMER’s guide on the Racketboy forums indicating how to identify copies of Gyromite for the NES which house an adapter to play Famicom games on the US NES.  Special thanks to CRTGAMER and Ziggy587.

Once in a while the inside of the Gyromite game cart has an NTSC-J Gyromite game PCB with a 60 pin Famicom to 72 pin U.S. NES adapter. While the cart itself is a bit of a novelty, owners can swap the PCB out with other NTSC-J NES PCBs, allowing them a way to play Japanese games on their US systems.

Gyromite Cart Comparison

Internals of a cartridge with the adapter and without.

There are several ways to identify whether a copy of Gyromite is the NTSC-U version or the special adapter version.  First, the adapter causes a change in weight, though the difference is only slight, coming in at roughly an ounce.  Normal cartridges weigh around 3.5 ounces, while the adapter version weighs in at about 4.5 oz.  While it’s not a great method for identifying an adapter unless one owns a postal scale, it can be a means to further one’s identification of a cart if it is suspected.  The weight increase also shifts the cartridge’s center of gravity, causing it to balance more towards the center, where the word “CAUTION” at the underline.  Regular carts will tip over at this point, but the adapter-equipped Gyromite will stay balanced.

As Gyromite cartridges have been released in the US, they have undergone some cosmetic changes.  Specifically the image of ROB the Robot in the lower left corner of the game has varied in color between purple and dark blue.  While there is some belief that the dark blue may indicate a cartridge with an adapter, forum member CRTGAMER has found one in a cart with the ROB icon in purple, proving that this also isn’t a good indicator.

The number of screws on the back of the cartridge can also help indicate whether the cart contains an adapter.  Later NES cartridges feature 3 screws (and eventually 3 security screws) on the back and hinges on the top of the cartridge.  These cartridges did not house the adapter.  But the earliest cartridges from Nintendo were held together by 5 screws and lacked the hinges of the later design.  While it’s not a foolproof method, a 5-screw Gyromite instantly warrants a closer inspection.

By far the best method to identify a copy of Gyromite with an adapter is to examine the contacts of the cartridge.  Normal copies of Gyromite contain small lines in the center of the contacts of the cartridge.  These lines extend from the end of the contacts towards the examiner and can be difficult to see unless you know what you are looking for.  Gyromite carts with the adapter also have these lines, but instead of extending from the center of the cartridge, these extend from the side.  These pictures will help illustrate the difference so you know what you’re looking for:

Example of a regular Gyromite PCB

Example of a Gyromite PCB with an adapter

Those looking for the game have reported that any five screw Gyromite cartridge with this style of contacts has an adapter inside.  It should also be noted that regular cartridges have PCB green sealer over the far ends of the contacts, though this may also be difficult to see when the cartridge hasn’t been opened.

Of course the easiest way to tell is to open up the cartridge.  Some members have claimed that certain retro game stores are ok with customers opening up Gyromite carts to identify which ones have adapters.  While your store may be ok with you doing this, make sure to ask before you pull out your screwdriver and start going to town.

Here some quick advice from Ziggy587 on his routine when checking these carts:

“”The easiest way to identify a cart that has the adapter inside is by looking at the contacts. It’s a little hard to explain with words alone, so check out the pictures. A Gyromite cart that does NOT have the adapter inside, and most (if not all) other NES games have a little line extending out from each contact. The line is dead center of each contact. Carts that DO have the adapter inside have a line as well, but it’s not centered, it’s clearly to one side of each contact.

This is by far the best way to find a cart with the adapter inside. You won’t look like a weirdo bringing a postal scale into the store or trying to balance it weird. And asking to open up carts might lead to the store owner not wanting to sell the game for its typical price if you find one with an adapter inside. They might even start opening all the carts to try and find the adapters, only to sell them for more money. I say leave them in the dark so we can found these carts in the wild with out any inflated prices.

So when I go into a used game shop, here’s what I do: First, I’ll identify all the 5-screw carts. This is easy to do since they don’t have the hinges. And since most retro game shops store their NES carts with the top side of the label facing you, it’s easy to look through a wall or bin of NES games and find all the 5-screw carts. I’ll take a look at the contacts of each and every 5-screw cart, and if I find one with the tell-tale sign of the contacts, I’ll probably notice the extra weight compared to the other carts I just handled.

No hinges on 5-screw carts

From what I’ve read, and experienced, if you find a 5-screw NES cart and the lines on the contacts are NOT centered, then 100% of the time it has an adapter inside. This is not limited to just Gyromite carts, but any 5 screw cart that was a launch game (although I believe the Gyromites carts with adapters are more common).”

For some additional information on the topic, here’s an article by Benj Edwards at Vintage Computing talking about the differences

“It’s not a myth if it’s true. Yes, Mario, there might be a Famicom to NES adapter in your copy of Gyromite. In fact, there might be an adapter in other early NES games, but so far, Gyromite is the only game cart I have personally found adapters in.”
-Benj Edwards

Stack-Up is another early NES release title which has a solid chance of containing an adapter.  This entry from the blog ? + 0 / 9 discusses it

“When Nintendo released Stack-Up and Gyromite for America, they were in hurry to sell American systems, so they didn’t manufactured independently NES cartridges, and put these 60 to 72 pin converters inside the NES cartridges. Some other games had these converters too, but the chance to find one is smaller than in Stack-Up cartridges.”
-? + 0 / 9

And here’s more information on which carts may contain the NES converter from Famicom World:


  1. Carts with adapters are slightly heavier, weighing 4.5 ounces (above the 3.5 ounce norm).  A postal scale will prove the exact difference.
  2. Cart balance also could be a factor, as the adaptor is more balanced towards the center.
  3. Gyromite carts with the adaptor have contacts that are individual unlike most other NES game carts.
  4. Gyromite carts have five screws not three, unlike most NES carts.
  5. The carts usually have slotted screws, not Game bit screws.
  6. The R.O.B. color label trick is too hard to tell even a close look, so it’s not a positive indicator.
  7. Look for carts without hinges to easily identify 5 screw carts on the store shelf.

Once again, thanks to CRTGAMER and Ziggy587.  Feel free to check out the original forum thread