[pups] 11/23 and other qbus machines

Tim Shoppa SHOPPA at trailing-edge.com
Sat Jul 1 21:00:37 AEST 2000

>I'm maybe going to acquire an 11/23.  It looks like this is kind of
>small for running v7 and/or 2.11 as it has no split I/D (it does have
>an MMU in it but only an 18-bit one I think).

Yeah, perhaps the best choice here would be the set of RL02's I found with
a V6 system on RL02 packs.  Hook up a RLV11 or a RLV12, a couple of
RL02 drives, and you're in business.

>How similar is the physical hardware (card cage I mean really) of this
>to things like 11/73,11/83?  I'm wondering if I might one day be able
>to acquire a card-set from something bigger and install it in the same
>rack, my logic being that cards are a lot easier to get from far away
>than racks, and this machine is only a few miles away.

It's very similar, but it's also rather likely that the card cage that your
11/23 comes in will only support 18-bit bus addresses.  If you want
to run 2.11BSD that's not really enough memory.  For some
details about what Q-bus hardware supports 18-bit stuff and what 
Q-bus hardware supports 22-bit stuff, please look at your Micronotes,
specifically #5, _Q22 Compatible Options_.  If you aren't lucky enough
to own a set, you can browse them at


In large part, it's impossible to specify a PDP-11 as a "PDP-11/23" and
know with any certainty what any single part of it is.  There's much
more to a system than the CPU (and note there are several very different
CPU boards sold as 11/23's), you also have to consider backplane, memory,
and disk/tape storage.  It'd be nice if Warren linked to some not-on-
Minnie resources for these subjects important to many PUPS members (hint hint,
nudge nudge!)

 Tim Shoppa                        Email: shoppa at trailing-edge.com
 Trailing Edge Technology          WWW:   http://www.trailing-edge.com/
 7328 Bradley Blvd		   Voice: 301-767-5917
 Bethesda, MD, USA 20817           Fax:   301-767-5927

Received: (from major at localhost)
	by minnie.cs.adfa.edu.au (8.9.3/8.9.3) id VAA05783
	for pups-liszt; Sat, 1 Jul 2000 21:13:56 +1000 (EST)
	(envelope-from owner-pups at minnie.cs.adfa.edu.au)

More information about the TUHS mailing list