Hi Ron - I reached out to BOSS to enquire, and this is what I got back ...
I'm sorry to say, that there is no specific MIDI implementation manual for the EQ-200.
The EQ-200 doesn't really have a static list of CC mappings, as when using the MIDI menu, you can effectively decide what each CC does.
For example:
SW CC → 1 (Define CC# to toggle EQ A/the left switch, I choose 1)
SW MEM → 2 (Define CC# to toggle EQ B/the right switch, I choose 2)
Not massively helpful, I guess ...