Thanks - I guess I should have done this first :-) Actually it says pretty much what I expected except for figure 1-9 on page 1-8. This shows that slots 4 and 6 in the H9273 are wired differently (it implies that they have no QBUS connection!) from the adjacent slots. That seems hard to believe - can that really be true?? Were these slots reserved only for things like the second card in the RLV11? Another question - this diagram implies that the BDV11 is always in the bottom slot regardless of how many cards you have. Is that correct? Do you need grant continuity cards then for all the empty slots? Other than that, table 2-1 describes the jumpers and it looks like it says pretty much the same thing as the Microcomputers and Interfaces handbook - W2 and W3 are inserted for the first chassis, and removed for an expansion chassis. It doesn't look like any of the front panel jumpers would be affected by the type of the CPU card. Thanks again, Bob