decserver 550 in Kansas City

From: Ethan Dicks <>
Date: Thu Feb 27 13:03:00 2003

--- "Zane H. Healy" <> wrote:
> I can't remember how much memory is onboard, but there should be enough
> to to run RT-11.

Mine has 512KB.

> Such a setup seems to be popular for 2.11BSD for some odd
> reason.

Is that sarcastic? I have lots of experience with 2.9BSD (I've had
distro tapes for 15+ years and have installed it on a number of real
PDP-11s and some old versions of SIMH (which is how I helped Bob find
the implementation bug with the RP emulation). I have stuck with it,
because until I recently aquired the DECserver CPU board, I didn't
_have_ a Q-bus J-11 board, just several F-11 boards (11/23 and 11/23+
CPUs). 2.9BSD does not require Split I&D and runs fine on an 11/23
or 11/24 (but it's nice to have more than a pair of RL02s to house it)

2.11BSD is desired by lots of folks because it has MSCP support built-
in (ISTR there are patches for 2.9BSD for it). These same people don't
mind that 2.11BSD requires Split I&D because now, J-11 systems are
widely available and, below the 11/83, inexpensive. You can have a
servicable 2.11BSD system in a BA-23 with this CPU board, an RQDX3
and an ST-225 (RD31). You can have a decent system with an ST-251 (RD32).
With an RD53 or RD54, you can really play. There are other disk options,
but the commonly available arrangements are more than satisfactory.

Also, MHz aside, you don't typically need what an 11/53 CPU offers
if you are going to be dabbling in RT-11. Even v5.7 is servicable
with far older hardware. The speed is nice, but I never complained
about running v5.3 on my 11/23 w/256K. I don't think there's much
out there for the RT-11 world that you *need* a J-11 chip. TSXplus
might be different; don't know - only ever run that on an 11/73 and
I was a lowly user.

> The big problem with these boards is that due to the bulkheads on the
> boards, they'll work best in a BA213, rather than the normal chassis used
> for a PDP-11.

Good point. I was going to remove my bulkhead since I have *no* BA213
equipment anywhere (and I have some COMBOARD handles...) I just wasn't
sure how I was going to handle (no pun intended) the I/O board that's
mounted up in there... too long and thin for a regular BA23 I/O panel.

I'm still looking for a BA213 or two for "haul-it-away" prices. I wish
I'd gotten to the trailer at the back of the Hamvention lot last Spring
before Mitch Miller did - I'd have loved to get that uVAX-III with
dual Ethernet for a song. I might have even left the CPU in it. :-)


> Zane
> --
> | Zane H. Healy | UNIX Systems Administrator |
> | (primary) | OpenVMS Enthusiast |
> | | Classic Computer Collector |
> +----------------------------------+----------------------------+
> | Empire of the Petal Throne and Traveller Role Playing, |
> | PDP-10 Emulation and Zane's Computer Museum. |
> | |
Received on Thu Feb 27 2003 - 13:03:00 GMT

This archive was generated by hypermail 2.3.0 : Fri Oct 10 2014 - 23:35:57 BST