17 Jul
2004
17 Jul
'04
7:11 p.m.
On Jul 17, 22:47, Robert Armstrong wrote:
Is there a description anywhere of the backplane changes that need
to
be made to upgrade a BA11-N (H9273 backplane) for 22
bit addressing?
All you need to do is take 4 lengths of wire-wrap wire (or something
similar) and join together all the pins that connect to the BC1
fingers, all the BD1, all the BE1, and all the BF1.
If you can view (or print) PostScript files there's a diagram showing
the finger layout at
http://www.dunnington.u-net.com/public/PDP-11/
QBusConns.ps is actual size, QBusConnsBig.ps is somewhat larger. I
expect there are text lists of the signals/fingers around the web too.
If you plan to use a processor with PMI memory you might also want to
link AF1 on the first (top) slot to AF1 on the slot (or two slots)
immediately below. That's the SRUN connection; without it the RUN LED
won't light.
--
Pete Peter Turnbull
Network Manager
University of York