I wish the classiccmp archives were back online for in 1997 Daniel A. Seagraves has similar issues. My VAX 11/780 still hasn't booted, I just can't seem to be able to close the loop to proper UDA50 use. Today I checked the UNIBUS backplane NPG wiring and I found that the CA1-CA2 jumper was under slot 2,3,4,6 and 8 while there was no such jumper under slot 5. Since the first 4 slots were all full with those standard printer and serial interface I left those alone and placed M7485 in slot 5 and M7486 in slot 6. Before I had it reversed. My UDA50 user guide seems to imply that the usual arrangement is first M7486 and the M7485, however, this is not stated in writing (only in pictures.) What is stated in writing is that the M7485 absolutely must have that NPG jumper removed whereas for M7486 it didn't matter. They go on saying that if NPG jumper is removed for both slots, then the two cards can be swapped into either order. I concluded that I could swap them as long as M7485 has the NPG jumper removed, hence I could make that arrangement without having to actually cut a wire on the backplane. Both cards now show the idle cycling-pattern, no errors, but also no reaction to the host computer when I try to make it boot. I guess now the question is: is any of my assumptions wrong about the ordering of the two UDA50 modules? And: did I set the right UNIBUS address and does my DUABOO.CMD file actually use that same address. Is there any simple way of manually testing the UNIBUS address by DEPOSITing some machine program to read out some UNIBUS register so that I can scan the bus to check the right address rather than having to rely on me making no mistakes? thanks, -Gunther