Roland JX-10 aka Super JX has three EPROMs: ROM A (the main board or Assigner board), ROM B and ROM C (these are the module boards, or voice boards). The modules boards EPROMs are version 2.10.

There is a ton of bug fixes and improvements with every new version.

To check your ROM version, just hold the H button (under "PATCH") while powering up your synth.
Contact if you need help.

Price with shipping charge included (registered mail).