12 Dec
2005
12 Dec
'05
8:03 p.m.
Subject: Re: PDP-11/73 booting!
From: Doc Shipley <doc at mdrconsult.com>
Date: Mon, 12 Dec 2005 20:59:26 -0500
To: General at mdrconsult.com, "Discussion at mdrconsult.com":On-Topic and
Off-Topic
Posts <cctalk at classiccmp.org>
Allison wrote:
The BA23 came with a microPDP-11 backplane or one for the uVAX-II.
While the differences are small when used with care they are differnt.
For the PDP-11 use the MicroPDP11 backplane is desired as the uVAX
one has three slots that are CD wired for PMI bussed memory.
the DISK interface and distribution board in the back of the drive
cavity however are the same.
So if you have a uPDP-11 ba23 you have the disti board and all you need
is a 50pin to 50pin to connect that to the RQDXn and the from there the
needed (short) cables to the specific drives.
Allison
Certainly if you can find a BA23 with the rack kit that would be an ideal
solution just make sure it has the PDP-11 backplane (can have a different
one for VAX). Then you can transfer the modules you have to it and have
more usable slots as the backplane is 18 slots (ABAB config). There's
a plus you'll have the distribution board for the in box mounted RX
and RD drives.
Can you elaborate on this?
I'm running a PDP-11/53 and a PDP-11/83 in BA23s that originally
housed MV-IIs. I never knew there's a difference.