These are some very modular SMD disk controllers emulating DEC MASSBUS controllers and their drives. They use two differnd kinds of controller boards, both have connectors for two B-cables but only one has a connector for an A-cable. You can install up to four controller boards, connecting up to eight drives daisy-chained using one controller board with an A-cable connector and three without or four drives using four boards with A-cable connectors. Each controller needs at least one interface board which connects through a ribbon cable to a unibus controller, but you can stuff four of them in to let four VAXen or PDPs access the disks at the same time. I haven't played with them yet, and even if i would hook it up to the -11 i don't think i could find any of the CDC disks they need.
