🚀 go-pugleaf

My love is the pdp-11, but a microprocessor company has given small-address
machines such a bad name ...

With regard to the pdp-11 and the -10, I recall a puzzling fact from the
PDP-11 Peripherals Handbook.  Out of a large collection of peripheral products
there was one which did not have "11" in its name.  This was the DL10
Unibus window.  It was also unusual in that it might not return slave sync
for a ridiculously long time, like 30 seconds.

I know DEC-20's used 11/40's as front end machines.  Did they interface via
a DL10?  Could someone briefly describe what services the 11/40 did?
(Or it might have been labelled 11/35 -- same set of CPU cards.)