On Fri, Oct 20, 2023 at 12:11 PM Jon Elson via cctalk <cctalk@classiccmp.org> wrote: > On 10/20/23 03:59, Michael Thompson via cctalk wrote: > > The RICM has an empty 11/20 chassis and the power supply. All it needs is > > the processor backplanes. Is there any chance you have a set of backplanes > > available? > > > I have a DD11-PK backplane (Part No. 70-11523) with a few > bent pins. None are bent so badly they can't be > straightened. From 11/04 or 11/34. Free if you pay shipping.
DD11-PK is for 11/34 (top two slots for CPU). PDP-11/04 uses standard DD11-DK (single-board CPU, doesn't need special slots). The 11/20 is entirely different. It has three 4-slot backplanes for CPU boards with "random" wiring and Unibus out on AB of final slot. It would be unusual but not impossible to see the 11/20 CPU backplane assembly outside of a BA11-C cabinet. If one had 12 DEC backplane blocks, one could make a replacement but it would be quite an undertaking. Might be easier to make a PCB-based replacement with modern connectors. Could also upgrade power input scheme while at it. -ethan
