11/44 memory question

You don't need grant cards in the 11/44 backplane slots 9-12 since they are not SPC slots. The AB portion of the slot is 'extended unibus' EUB (adds address lines 18-21 for 22b addressing) but the CDEF sections are not SPC slots. If they are not used for memory they should be left empty; you can put a grant card (either type) in these unused slots -- it won't hurt anything, but it is not necessary. Empty memory slots cannot be used for UNIBUS SPC modules either. Only the last two quad slots 13,14 CDEF in the 11/44 backplane are SPC and these require G727A/G7273 grant cards depending on whether the NPG wire has been removed. The modules have the grant propagation lines intact because they could *theoretically* go in a MUD (modified unibus, 18b, with associated SPC section) or an EUB (22b) slot. These modules work in the 11/44 (dedicated EUB memory) slots or the 11/24 (MUD/EUB/SPC slots) which need grant propagation.