This disk drive has a capacity of 168.5MB. I found a Emulex SC41 MSCP-emulating SMD controller configured for it, and the configuration sheets in its manual state that it was supposed to run with the 11/24 with RSX-11M+. I guess it still has an installation of RSX on its platters.
The paper on the cover says that it got its last maintenance in 10/1982. It is quite impressive that it still works today. (Well, at least its "Ready"-light goes on after some minutes, and i was able to read it with the UD33 firmware.)