via this auction
"Yamaha DX7 FM 1024 HYPRA ROM sound bank cartridge [Extremely Rare!] 1024 Patches. Comes with the original Yamaha ADP-1 adapter cradle for the different versions of the Yamaha DX7 type FM synths which in itself is quite rare and seemingly quite expensive by itself if other Ebay auctions are to go by (feel free to check).
Reasonable condition (apart from missing switch cover - see pic) although this has been kicking around since the 80s so shows the signs of being used, scratches and dings as per the pic - This is very hard to find data rom cartridge made in Germany for the DX7 1024 sounds. There are 3 switches to chose between banks and patches. Switch 1 from A-D, 1 from 1-4, 1 with Alpha and Beta, resulting in 4 x 2 x 4 banks - which means 32 x 32 = 1024 presets for the DX7.
I have absolutely no way of testing this unit as my DX7 has long since gone and there is a real possibility that it may have lost its memory or does not even work thus I am selling this with this caveat. Then again it might work absolutely fine if you plug it in.... I have genuinly no way of telling but the adapter is probably worth quite a bit by itself."
