Hi All,
I've got a likely fully working KAS Board up for auction in the US on E-bay:
https://www.ebay.com/itm/Yamaha-CS80-CS-80-vintage-synth-KAS-Board-YM-26600-and-YM-26700-IC-chips/152875868286?hash=item23981ca07e:g:oYAAAOSwRLZaXp7m
Regards,
Kyle
jkjelec