How to Make a CX4 Multi Cart – Mega Man X2 and X3

Today I finally got around to editing a video on my 27C322 to CX4 adapter board for making CX4 multi-carts. Check out the video!

The video covers how to install the hardware but I figured I’d also write up something here explaining how to create the ROM file for this cartridge.

Supplies Needed:


  1.  A legally acquired ROM of both Mega Man X2 and Mega Man X3 respectively.
  2. A Hex editor like HxD.
  3. For convenience I made a 512k pad file that you can download here.



How to do it:


Open HxD and navigate to Tools > File Tools > Concatenate


Click add and navigate to the location of you Mega Man X2, X3 ROM files and you 512k Pad file.


Highlight all three files and click Open.


Organize the files so that Mega Man X2 is on top, followed by the 512k Pad file with Mega Man X3 at the bottom. Also set an output file location and name then hit OK to run the process.

Once you are done you should have a 4MB file with X2 and X3 combined together which you can burn directly to your EPROM.


It’s really that simple. My adapter is available for sale now. I can also provide programming services for anyone buying the adapter and an EPROM from me, but you must send me your own file. I can’t provide the ROM file for obvious reasons.

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June 20, 2019 arthrimus

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