16 May
2012
16 May
'12
12:38 p.m.
This machine has a controller for RK05 drives which takes 4 unibus
slots. It may have been the driver for the case choice.
Yes, that would explaim it.
The PDP11/04 CPU board (and for that matter the 11/34 CPU boards) has to
go in a special 9 slot backpalne. The remaining slots of that can be used
for the frontpanel interface (if you have one), memory, SPC (small
peripheral controllers) and so on.
The RK11-D cotnrolelr for the RK05 is 4 boars that have to go in their
own speical 4-slot backplen, they can't go in the CPU backplane slots.
Now, the 5.25" box (BA11-L) can only take one 9 slot or 2 4 slot
backplanes. So it can take the CPU backplane, but there's no space for
the RK11-D.
The 10.5" box (BA11-K) can take the CPU (9 slot) backplane, and 3 mroe 4
slot backpalens, or a 9 sltor and a 4 slot backplane (actually, it can
take 6 4 slot backples too, if you're not using it for the CPU). So you
could put the CPU backplane nad hte RK11-D in there and have room to spare.
Having the CPU io nthe bigger box would be simpler and cheaper than
adding a second box as an expansion cabinet to hold the RK11-D.
-tony