strange behavior with microvaxii in ba23 box

[hush]

hey all, was working on my mvii build last night, and after shutting it down to get some dinner i came back to it having a whole host of issues. i have been working through bit by bit trying to figure out what is wrong, but the current issue i am having has me stumped. my backplane (h9278) is laid out as follows:

ka630
mem 4m
mem 8m
qbone
delqa|dhq11
rqdx3

CD GRANT lines on the qbone are closed. if i boot into microvax diagnostic monitor with this configuration, it can only see the following devices:

• RQDXA (qbone)
• DEQNAA
• RQDXB (rqdx3)

if i pull the rqdx3 from this configuration, i will see the following:

• RQDXA (qbone)
• DHU11
• DEQNAA

stranger still, if i boot into either vms or mdm in the configuration where the rqdx3 is working and present, but with a drive attached, the controller will not be recognized. any thoughts? please let me know if any of this is unclear, it's a bit of a braindump after a frustrating few hours...

quick crappy mspaint visual in case it helps

 

[cruff]

Do you perchance have another emulated device on the Qbone that might be causing some interference? What happens if you move the Qbone after the other devices?

 

[hush]

Do you perchance have another emulated device on the Qbone that might be causing some interference? What happens if you move the Qbone after the other devices?

at the time i'm testing i'm only booting either vms (two disks, same controller) or mdm (rx50s, one at a time, same controller)

i previously had the qbone at the very end of the bus when the machine started having these issues, i moved it under the memory to start building up and testing one device at a time, so afaik the behavior isn't any different whether it's above or below, it's like there's just this strange blank spot in my backplane that i can't figure out, but it isn't the slot itself

e: i know that for pdp11 systems the starting LUN must be jumpered to prevent conflicts across controllers, but i believed that wasn't the case on VAXen. DUB starts at LUN 0, as does DUA. maybe i'm wrong?

 

[cruff]

Do you have an addressing conflict between the rqdx3 and the dhu11?