26 Feb
2003
26 Feb
'03
1:40 p.m.
--- Tony Duell <ard(a)p850ug1.demon.co.uk> wrote:
What the heck is an ASR33 if not a serial terminal????
Umm... well... yes. But that's not what I was thinking of... I was
thinking more along the lines of LA-36s and DECwriter IVs and
everything in between - RS-232 (EIA) dot-matrix serial printing
terminals/serial printers (no keyboard).
I stand (multiply) corrected that the ASR-33 _is_ a serial terminal.
COnsidering there's little, if any, difference
between the 2 types of
machine _in software_, there's no real reason why Q-bus machines would
have multiple DL11-type ports and Unibus machines wouldn't. Other than
possibly the fact that DEC made a 4-port DL11 for Q-bus (DLV11-J) but not
for Unibus.
That's the reason. In my experience, more F-11-based Qbus machines
had DLV11Js than DLV11Es (J-11s tended to have things like the quad
DZ cards also found in MicroVAXen).
3rd parties made 4 and 8 port Unibus DL11s, though.
Haven't seen those. They sound interesting. I have seen (and have
myself) quantities of Emulex Unibus 16-port DZ (and DH?) cards.
Depending on the firmware and PALs, under VMS they show up as 16
TT devices (TTA0-TTA7/TTB0-TTB7) or 16 TX devices (TXA0-TXA7/etc.)
But as mentioned before, those aren't necessarily going to be happy
under RT-11.
-ethan