Just to add to the comments from others... These sort of cards were used in industrial controllers, where lots of I/O was needed... stuff like relay controll & sensor inputs. They plugged into what's called a passive backplane, which is just a bunch of ISA or PCI connectors wired in paralell. - Just like the ISA slots in the big box Amigas. They get power from the bus, but can use it as well. If you put one of these in the Amiga, it could use the ISA cards, but the Amiga would never know it was there. For that you need a Bridgeboard, that plugs into both the Amiga and ISA slots. Commodore and a couple 3rd parties made them, back in the day.