DU device became available with RT V5.0. It supported
RQDX1. I
think that RQDX2 was supported with V5.1 (though it may have been
latently supported with V5.0).
I had to trade back some RQDX2s for RQDX1s on some PDP-11/73s I delivered
to the gummint because RT-11 didn't support them. I don't recall which
version we were using; it would have been at least 5.0. I remember
grumbling about how fancy (read "bloated") RT-11 was getting, but I don't
recall doing _that_ until 5.2; I thought it happened during the 11/73
incident, though. I also don't remember why I thought 5.2 was bloated
(it may have been the UCL/UCF stuff, which I thought was unnecessary),
but I did stash away a 5.0 distribution kit as a hedge against bloatation.
Roger Ivie
ivie(a)cc.usu.edu