Was each publisher using their own connector or was there an industry standard? Before the JAMMA standard, it was truly chaotic. Manufacturers didn't real

Was each publisher using their own connector or was there an industry standard? Before the JAMMA standard, it was truly chaotic. Manufacturers didn't really have their own per-manufacturer connectors; it was more like each individual game had its own custom wiring setup. Manufacturers would sometimes release upgrade kits for specific existing machines. For example, Atari created Black Widow as an upgrade kit for existing Gravitar machines (and only Gravitar) JAMMA wasn't a magic cure for everything. It specifies pinouts for buttons and things but there can still be e.g. video sync issues. But it was a huge step forward. In Japanese arcades you would see a lot of these standardized cabinets. They allowed arcade operators to swap in a new JAMMA (etc) game at low cost with close to zero effort. Sega's Astro City cabinet is probably the most famous, I think. https://en.wikipedia.org/wiki/List_of_Japanese_arcade_cabinets https://en.wikipedia.org/wiki/List_of_Japanese_arcade_cabine...