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Qbus
March 6th, 2011, 10:51 AM
On my 11/23 I have three empty slots between the last card in the first frame and the 9400YD card and its jumper to the 9401 on the second frame. I installed all my memory M8044DK cards in the second frame but want to know do I need to install M9047 grant cards in the empty slots in the first frame for the memory and BDV-11 in the bottom frame? Do M8044 get vectors or interrupts? My idea is and not necessarily right but what I think, the grant cards carry the interrupts or vectors to the CPU, they are carried looping thru each card with the cards requiring the highest priority being closest to the CPU, by having three open slots in the top frame their may be a issue although I am running somewhat.

RSX11M+
March 6th, 2011, 02:35 PM
In your case, there is probably no need to install any grant cards.

However, as soon as an I/O device which generates either interrupts or DMA were to be placed in your second backplane, you would need grant cards in the FIRST backplane in any empty AB slots between the expansion cables and the CPU.

You seem to be asking general rules for device order... Chapter 11, page 11-2 in the 11/03 Users Guide EK-LSI11-TM-002.pdf pretty much covers it.

In general, memory devices do not generate interrupts or DMA, so your MSV11 and BDV11 need not be contiguous with other cards, although it is not customary to place RAM memory so far from the CPU.

Usually, my systems are: CPU, Console Serial, Memory, other IO, Disk Controllers.

NOTE:

When one has a mixed "S" style bus and an RLV11 requiring CD slots, this order preference needs to be compromised. You have only ABCD slots, so this does not effect you.
Device order establishes device priority. [not to be confused with interrupt priority] Hence, console serial is the most important device if I expect to be able to use MicroODT to resolve potential hardware problems. DMA generating devices at the end, large block ones last.

Am I answering what you want to know?