[cctalk] Drum memory on pdp11's? Wikipedia thinks so....

Was reading the Wikipedia article on Drum memories: https://en.wikipedia.org/wiki/Drum_memory#External_links And came across this tidbit. As late as 1980, PDP-11/45 machines using magnetic core main memory and drums for swapping were still in use at many of the original UNIX sites. Any thoughts on what they are talking about? I could see running the RS03/RS04 on a 11/45 with the dual Unibus configured so the RS03's talk to memory directly instead of the Unibus, but that's not quite the same as true drum memory. Closest thing I remember was the DF32 on a pdp8 which could be addressed by word as opposed to track/sector. Thoughts? C