If I understand well this is not normal RAM where you can can save banks or individual patches in standard way on DX7.

It has to be programmed in EPROM programmer, and common SysEx bank data has to be converted before.

So if Chris will not offer his card with some pre-programmed EPROM (for example with all original Yamaha ROM’s and some usual random garbage from the internet - because I don’t think he would make some order or patch categorization in it, it’s too much work, or maybe he can use DEXED archive), you have to send him your own patch selection (256 banks) what you want to have on the card, and he will program it.

That means probably don’t expect you will get some “rom card ready for use”.

Daniel Forro?