Plessy core memory

I assume theat "DD11-F" is a typo; there is, AFAIK, no DD11-F, and a Web search revealeddidn't turn anything up. (There are DD11-CF and -CK backplanes, as well as -DF and -DK, but the -CF and -CK differ only in power harness length.) The: https://gunkies.org/wiki/MS11-M_MOS_memory I'm guessing it used the parts that the IC vendors could provide. Not sure. Per: https://gunkies.org/wiki/Modified_UNIBUS_Device#Pinout https://gunkies.org/wiki/Extended_UNIBUS#Pinout These are _some_ of the MUD/EUB pin clashes: Pin EUB MUD AN1 - A21 - Parity P1 AP1 - A20 - Parity P0 BE1 - A19 - Internal SSYN BE2 - A18 - Parity Detect I don't think those would harm anything. Not sure about power pins - and have no incentive to research it, as I have no need/interest in trying it. Maybe Plessey designed them to go in a DD11-B? I know I've seen other third-party cards that would go in oddball slots. Why not? The two hexes in slots 2&3, the quad in 1 or 4. Wow; never heard of those. I'll have to do a CHWiki page for them. Luckily, the maint manual is online. There's also a DA11-B. All that does is allow DMA devices on the -11/24's UNIBUS access to the entire main memory: https://gunkies.org/wiki/PDP-11/24#System_bus_structure So if you hooked up an -11/10 to an -11/24 with a DA11-F, then with the UNIBUS Map on, the -11/10's CPU and/or DMA devices would have access to the entire EUB memory via the 24's UNIBUS Map, is all. That _is_ why we collect old computers! ;-) Noel