On Tue, Jun 21, 2016 at 9:05 PM, Michael Thompson < michael.99.thomp...@gmail.com> wrote:
> The RICM just picked up a PDP-11/40 chassis that was modified to accept a > PDP-11/23 board set. It also contains a custom board to interface the > PDP-11/23 to the original PDP-11/40 front panel. It is quite an > accomplishment to get the Q-Bus board set working in the Unibus chassis. > I looked at the backplane pictures that I took after the rescue. I assumed that the hex-wide 8-slot backplane in the front of the card cage was the original 11/40 processor backplane. On the back it says "LSI 11 BACKPLANE", so the operation is not so mysterious. I had never seen a hex-wide Q-bus backplane before this. There are some pictures of the system and the Q-Bus to 11/40 front panel interface here: http://www.ricomputermuseum.org/Home/equipment/dec-pdp-1140 -- Michael Thompson