That's the NOA-60022 digital harness. If you don't have one, they're quite rare and very expensive! The European and Japanese ones were different - I'd imagine the US ones were, too. Try asking Sega... if not, you'd have to import one: http://www.giz10p.co.uk/Cabinet-Par...Harness-Japanese-Ver-NOA-60022-/prod_429.html Note that's the Japanese version and he explains the differences.
I've bought a few off eBay in the past year or two for my New Astro City JVS refit project. Best things to look for are parted out Nami universals.