I still remember having my mind blown at a Pirates of Puget Sound party in the 80s where there were banks of 1541 drives connected in pairs happily copying disk

I still remember having my mind blown at a Pirates of Puget Sound party in the 80s where there were banks of 1541 drives connected in pairs happily copying disks with no C64 connected to the drives. Just insert two disks and it would copy from A to B. That was when I realized the 1541 drives weren't just drives, they were computers themselves.