HOWEVER, while the PDP-11 is still unable to perform
an
LLF on an RX50 when an RQDX3 is present, it is possible
to perform an LLF on a floppy in an RX33. Does that still
seem compatible with your explanation?
Yes, that confused me too. The RQDX3 is clearly capable of
LLFing a floppy. So either (unlikely) DEC specifically do
not allow the right set of commands to LLF an RX50 or
(more likely) that bit of software you have doesn't do it
(although others can) possibly so as not to cut into DEC's
sales of pre-formatted disks.
Sorry I don't know more, the RQDXs are too modern for me.
-tony