@lethargyman, a lot of arcade boards output TTL Csync but it doesnt hurt to run it through a stripper/cleaner anyway ; this is what @Frank_fjs 's syncbooster does (you can grab gerbers from his minigun post page1) it strips 8 pin mini din input's sync to TTL csync, outputting it to a db15 which plugs directly into the OSSC. i have spares and will be buying more PCB's soon. syncbooster is great, i also use it with my RetroScaler A1 as it gives me a no-fuss, always sync-able solution. Also, while jamma is RGBS format (whatever that actually means), jamma sync can be in so many forms, its quite rare for a console or even arcade board to sync up on an OSSC on AV3 using RGBS option.
needless to say im very excited about the new betsubetsu too! (ive already annoyed @buffi about it a bunch and he knows I am keen for the gerbers and BOM, when they're ready)
needless to say im very excited about the new betsubetsu too! (ive already annoyed @buffi about it a bunch and he knows I am keen for the gerbers and BOM, when they're ready)

