11/44 memory question

[Dennis Boone]

 > 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.

FWIW, my "PDP-11/44 System Technical Manual" (EK-KD11Z-TM-001,
1980) provides this information on pages 3-1 and 3-6.

De