As i remember DEC was selling its high speed reader (
PC11 ?) but only
for fanfold tapes.
There were also 3rd-party paper tape punch/reader systems that were
software-compatible with the PC11. I have an interface card in my 11/45
that talks to a Trend HSR700 (700 cps) reader and a Facit 4070 (75 cps)
punch. I am pretty sure Facit sold a Unibus interace card for their
reader too.
Maybe this can archived by adding one extra interface to the unibus
and a piece of software.
AFAIK there is no reason why you can't add another DL11 serial interface
(with a different Unius address and Interrupt vector) to link to your
ASR33. I am not sure about the driver -- the DL11 is somewhat
register-compatible with the PC11, so it might be a very simple
modification of the PC: driver.
-tony