DEC PDP-14 Programmable Controller simulator

I have written a PDP-14 simulator using the simh framework. Paired with a PDP-8 simulator as a front end it passes all the DEC diagnostics. A pointless effort, perhaps, because there isn't much that can be done with it without connecting it to something to control. In the course of research, I saw that there was an option to replace the braided core ROM that was standard, with a R/W core memory. It used a 4k memory module from the PDP-11 (MM11-E) with a special interface module in the PDP-14. I can find no documentation for the interface other than the wire-wrap list for the slot in the PDP-14 that it went into. From the signals available I have not been able to reverse engineer the instructions used to write the core or any detail really on how it might have been used. The option was MM14-A consisting of an interface (M7407), memory (MM11-E), chassis, and power supply. If anybody is still reading, I would be very interested in ANY information about it. -chuck