Partial tested midi interface.
Schematics based on https://groups.google.com/forum/#!topic/comp.sys.cbm/bPifzgUwfro
with 8k rom socket ($8000-9FFF).
To use rom, close JP1 and JP2
design partial tested
Rom found and running, midi detected by cynthcart v2.0
(note, running cynthcard V2.0 from 8k rom needs some crunching and relocation routine in rom as well)
Midi part not tested (I don't have midi...