PDP-11 SMD drive cabling

From: Pete Turnbull <pete_at_dunnington.u-net.com>
Date: Sat Dec 23 21:14:17 2000

On Dec 24, 1:58, Tony Duell wrote:
> > Now then, I've got an RL02 pack labeled RSX-11M, which I'm hoping
> > contains a complete RSX-11M distribution. If I can get an RL02
> I would doubt it. From what I remmeber, RSX11M 4.x was about 3 RL02 packs
> 5 RL01 packs, or 1 RK07 pack. 3.x might be a bit smaller, but it would be
> a squeeze to get it onto a single RL02, I think.

You can get a working system on one RL02, you can get a minimal working
system onto a pair of RX03s (double-sided RX02), you can just barely get a
bootable system onto a pair of RX02s (I've done all of the above).
 However, the distribution comes on five RL02s, of which you need at least
two (maybe three, it's a long time since I did a SYSGEN) to build a working

3.x is indeed smaller -- I've seen several systems with all the system
required on an RL01 and user data on a second one.

> > controller board for the 11/73, will there be any problem with just
> > connecting one of the SMD cables to the CDC drive and copying RSX-11M

The bootstrap will be different, and what you need to do will depend on
what your controller emulates -- it could be multiple RL02s, a few RK06s or
RK07s, or a couple of RM02s. Or possibly other things; it will depend on
the controller. Even if the boot block were the same (some drive types
shared the same boot block), you still need the driver and that probably
isn't present on a working RL02 pack unless the original system had both
types of drive. It might be on your 11/73's disks, if you have RSX on

As for booting from "any PDP-11", no it will depend on how the system was
built. It will depend on the machine having at least as much memory as the
original, whether it was built "mapped" or "unmapped" (memory management),
and whether it was built for separate I&D space. Other differences will
probably generate error messages, but as far as I remember won't stop it

I'm sure someone else asked about this on the list a year or two ago; it
might be worth looking through the archive.

Pete						Peter Turnbull
						Network Manager
						Dept. of Computer Science
						University of York
Received on Sat Dec 23 2000 - 21:14:17 GMT

This archive was generated by hypermail 2.3.0 : Fri Oct 10 2014 - 23:32:50 BST