Offered for sale is this Maartists MusicPack MR-5 RAM pack suitable for DX-7 MKII and other vintage modules that accept data cartridges like RX-5, TX-802 and DMP-7.
This is a RAM4 pack and had four 128mb banks - Level 1 and 2 banks A and B. I last used this cartridge on a DX-7 MKII about 3 years ago so cannot say whether any internal lithium battery installed is still OK so please bear this in mind.